Merge branch 'frontier/blockpool' of https://github.com/ethersphere/go-ethereum into ethersphere-frontier/blockpool

16 files changed, 735 insertions, 542 deletions

diff --git a/blockpool/blockpool.go b/blockpool/blockpool.go
index c5af481a7..09b9e7b0b 100644
--- a/blockpool/blockpool.go
+++ b/blockpool/blockpool.go
@@ -7,8 +7,10 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/errs"
+	"github.com/ethereum/go-ethereum/event"
 	ethlogger "github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/pow"
 )
@@ -32,12 +34,15 @@ var (
 	blockHashesTimeout = 60 * time.Second
 	// timeout interval: max time allowed for peer without sending a block
 	blocksTimeout = 60 * time.Second
-	//
+	// timeout interval: max time allowed for best peer to remain idle (not send new block after sync complete)
 	idleBestPeerTimeout = 120 * time.Second
+	// duration of suspension after peer fatal error during which peer is not allowed to reconnect
+	peerSuspensionInterval = 300 * time.Second
+	// status is logged every statusUpdateInterval
+	statusUpdateInterval = 3 * time.Second
 )
 
-// config embedded in components, by default fall back to constants
-// by default all resolved to local
+// blockpool config, values default to constants
 type Config struct {
 	BlockHashesBatchSize       int
 	BlockBatchSize             int
@@ -48,26 +53,41 @@ type Config struct {
 	BlockHashesTimeout         time.Duration
 	BlocksTimeout              time.Duration
 	IdleBestPeerTimeout        time.Duration
+	PeerSuspensionInterval     time.Duration
+	StatusUpdateInterval       time.Duration
 }
 
 // blockpool errors
 const (
 	ErrInvalidBlock = iota
 	ErrInvalidPoW
-	ErrUnrequestedBlock
 	ErrInsufficientChainInfo
 	ErrIdleTooLong
+	ErrIncorrectTD
+	ErrUnrequestedBlock
 )
 
+// error descriptions
 var errorToString = map[int]string{
-	ErrInvalidBlock:          "Invalid block",
-	ErrInvalidPoW:            "Invalid PoW",
+	ErrInvalidBlock:          "Invalid block",              // fatal
+	ErrInvalidPoW:            "Invalid PoW",                // fatal
+	ErrInsufficientChainInfo: "Insufficient chain info",    // fatal
+	ErrIdleTooLong:           "Idle too long",              // fatal
+	ErrIncorrectTD:           "Incorrect Total Difficulty", // fatal
 	ErrUnrequestedBlock:      "Unrequested block",
-	ErrInsufficientChainInfo: "Insufficient chain info",
-	ErrIdleTooLong:           "Idle too long",
 }
 
-// init initialises all your laundry
+// error severity
+func severity(code int) ethlogger.LogLevel {
+	switch code {
+	case ErrUnrequestedBlock:
+		return ethlogger.WarnLevel
+	default:
+		return ethlogger.ErrorLevel
+	}
+}
+
+// init initialises the Config, zero values fall back to constants
 func (self *Config) init() {
 	if self.BlockHashesBatchSize == 0 {
 		self.BlockHashesBatchSize = blockHashesBatchSize
@@ -96,6 +116,12 @@ func (self *Config) init() {
 	if self.IdleBestPeerTimeout == 0 {
 		self.IdleBestPeerTimeout = idleBestPeerTimeout
 	}
+	if self.PeerSuspensionInterval == 0 {
+		self.PeerSuspensionInterval = peerSuspensionInterval
+	}
+	if self.StatusUpdateInterval == 0 {
+		self.StatusUpdateInterval = statusUpdateInterval
+	}
 }
 
 // node is the basic unit of the internal model of block chain/tree in the blockpool
@@ -122,31 +148,41 @@ type entry struct {
 type BlockPool struct {
 	Config *Config
 
-	// the minimal interface with blockchain
-	hasBlock    func(hash common.Hash) bool
-	insertChain func(types.Blocks) error
-	verifyPoW   func(pow.Block) bool
+	// the minimal interface with blockchain manager
+	hasBlock    func(hash common.Hash) bool // query if block is known
+	insertChain func(types.Blocks) error    // add section to blockchain
+	verifyPoW   func(pow.Block) bool        // soft PoW verification
+	chainEvents *event.TypeMux              // ethereum eventer for chainEvents
+
+	tdSub event.Subscription // subscription to core.ChainHeadEvent
+	td    *big.Int           // our own total difficulty
 
-	pool  map[string]*entry
-	peers *peers
+	pool  map[common.Hash]*entry // the actual blockpool
+	peers *peers                 // peers manager in peers.go
+
+	status *status // info about blockpool (UI interface) in status.go
 
 	lock      sync.RWMutex
 	chainLock sync.RWMutex
 	// alloc-easy pool of hash slices
 	hashSlicePool chan []common.Hash
 
-	status *status
-
-	quit    chan bool
-	wg      sync.WaitGroup
-	running bool
+	// waitgroup is used in tests to wait for result-critical routines
+	// as well as in determining idle / syncing status
+	wg      sync.WaitGroup //
+	quit    chan bool      // chan used for quitting parallel routines
+	running bool           //
 }
 
 // public constructor
+// after blockpool returned, config can be set
+// BlockPool.Start will call Config.init to set missing values
 func New(
 	hasBlock func(hash common.Hash) bool,
 	insertChain func(types.Blocks) error,
 	verifyPoW func(pow.Block) bool,
+	chainEvents *event.TypeMux,
+	td *big.Int,
 ) *BlockPool {
 
 	return &BlockPool{
@@ -154,15 +190,8 @@ func New(
 		hasBlock:    hasBlock,
 		insertChain: insertChain,
 		verifyPoW:   verifyPoW,
-	}
-}
-
-func severity(code int) ethlogger.LogLevel {
-	switch code {
-	case ErrUnrequestedBlock:
-		return ethlogger.WarnLevel
-	default:
-		return ethlogger.ErrorLevel
+		chainEvents: chainEvents,
+		td:          td,
 	}
 }
 
@@ -175,11 +204,13 @@ func (self *BlockPool) Start() {
 		return
 	}
 
+	// set missing values
 	self.Config.init()
+
 	self.hashSlicePool = make(chan []common.Hash, 150)
 	self.status = newStatus()
 	self.quit = make(chan bool)
-	self.pool = make(map[string]*entry)
+	self.pool = make(map[common.Hash]*entry)
 	self.running = true
 
 	self.peers = &peers{
@@ -188,16 +219,37 @@ func (self *BlockPool) Start() {
 			Errors:  errorToString,
 			Level:   severity,
 		},
-		peers:  make(map[string]*peer),
-		status: self.status,
-		bp:     self,
+		peers:     make(map[string]*peer),
+		blacklist: make(map[string]time.Time),
+		status:    self.status,
+		bp:        self,
 	}
-	timer := time.NewTicker(3 * time.Second)
+
+	// subscribe and listen to core.ChainHeadEvent{} for uptodate TD
+	self.tdSub = self.chainEvents.Subscribe(core.ChainHeadEvent{})
+
+	// status update interval
+	timer := time.NewTicker(self.Config.StatusUpdateInterval)
 	go func() {
 		for {
 			select {
 			case <-self.quit:
 				return
+			case event := <-self.tdSub.Chan():
+				if ev, ok := event.(core.ChainHeadEvent); ok {
+					td := ev.Block.Td
+					plog.DebugDetailf("td: %v", td)
+					self.setTD(td)
+					self.peers.lock.Lock()
+
+					if best := self.peers.best; best != nil {
+						if td.Cmp(best.td) >= 0 {
+							self.peers.best = nil
+							self.switchPeer(best, nil)
+						}
+					}
+					self.peers.lock.Unlock()
+				}
 			case <-timer.C:
 				plog.DebugDetailf("status:\n%v", self.Status())
 			}
@@ -218,6 +270,7 @@ func (self *BlockPool) Stop() {
 
 	plog.Infoln("Stopping...")
 
+	self.tdSub.Unsubscribe()
 	close(self.quit)
 
 	self.lock.Lock()
@@ -255,9 +308,14 @@ func (self *BlockPool) Wait(t time.Duration) {
 /*
 AddPeer is called by the eth protocol instance running on the peer after
 the status message has been received with total difficulty and current block hash
-Called a second time with the same peer id, it is used to update chain info for a peer. This is used when a new (mined) block message is received.
+
+Called a second time with the same peer id, it is used to update chain info for a peer.
+This is used when a new (mined) block message is received.
+
 RemovePeer needs to be called when the peer disconnects.
-Peer info is currently not persisted across disconnects (or sessions)
+
+Peer info is currently not persisted across disconnects (or sessions) except for suspension
+
 */
 func (self *BlockPool) AddPeer(
 
@@ -267,7 +325,8 @@ func (self *BlockPool) AddPeer(
 	requestBlocks func([]common.Hash) error,
 	peerError func(*errs.Error),
 
-) (best bool) {
+) (best bool, suspended bool) {
+
 	return self.peers.addPeer(td, currentBlockHash, peerId, requestBlockHashes, requestBlocks, peerError)
 }
 
@@ -281,12 +340,12 @@ AddBlockHashes
 
 Entry point for eth protocol to add block hashes received via BlockHashesMsg
 
-only hashes from the best peer are handled
+Only hashes from the best peer are handled
 
-initiates further hash requests until a known parent is reached (unless cancelled by a peerSwitch event, i.e., when a better peer becomes best peer)
-launches all block request processes on each chain section
+Initiates further hash requests until a known parent is reached (unless cancelled by a peerSwitch event, i.e., when a better peer becomes best peer)
+Launches all block request processes on each chain section
 
-the first argument is an iterator function. Using this block hashes are decoded from the rlp message payload on demand. As a result, AddBlockHashes needs to run synchronously for one peer since the message is discarded if the caller thread returns.
+The first argument is an iterator function. Using this block hashes are decoded from the rlp message payload on demand. As a result, AddBlockHashes needs to run synchronously for one peer since the message is discarded if the caller thread returns.
 */
 func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId string) {
 
@@ -297,7 +356,6 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 	// bestpeer is still the best peer
 
 	self.wg.Add(1)
-
 	defer func() { self.wg.Done() }()
 
 	self.status.lock.Lock()
@@ -322,11 +380,11 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 			return
 		}
 		/*
-		 when peer is promoted in switchPeer, a new header section process is launched
-		 as the head section skeleton is actually created here, it is signaled to the process
-		 so that it can quit
-		 in the special case that the node for parent of the head block is found in the blockpool
-		 (with or without fetched block)
+		 When peer is promoted in switchPeer, a new header section process is launched.
+		 Once the head section skeleton is actually created here, it is signaled to the process
+		 so that it can quit.
+		 In the special case that the node for parent of the head block is found in the blockpool
+		 (with or without fetched block), a singleton section containing only the head block node is created.
 		*/
 		headSection = true
 		if entry := self.get(bestpeer.currentBlockHash); entry == nil {
@@ -337,6 +395,7 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 				block:   bestpeer.currentBlock,
 				hashBy:  peerId,
 				blockBy: peerId,
+				td:      bestpeer.td,
 			}
 			// nodes is a list of nodes in one section ordered top-bottom (old to young)
 			nodes = append(nodes, node)
@@ -344,7 +403,7 @@ func (self *BlockPool) AddBlockHashes(next func() (common.Hash, bool), peerId st
 		} else {
 			// otherwise set child section iff found node is the root of a section
 			// this is a possible scenario when a singleton head section was created
-			// on an earlier occasion this peer or another with the same block was best peer
+			// on an earlier occasion when this peer or another with the same block was best peer
 			if entry.node == entry.section.bottom {
 				child = entry.section
 				plog.DebugDetailf("AddBlockHashes: peer <%s>: connects to child section root %s", peerId, hex(bestpeer.currentBlockHash))
@@ -375,7 +434,7 @@ LOOP:
 		default:
 		}
 
-		// if we reach the blockchain we stop reading more
+		// if we reach the blockchain we stop reading further blockhashes
 		if self.hasBlock(hash) {
 			// check if known block connecting the downloaded chain to our blockchain
 			plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s) found block %s in the blockchain", peerId, hex(bestpeer.currentBlockHash), hex(hash))
@@ -412,10 +471,11 @@ LOOP:
 			// reached a known chain in the pool
 			if entry.node == entry.section.bottom && n == 1 {
 				/*
-					the first block hash received is an orphan in the pool
-					this also supports clients that (despite the spec) include <from> hash in their
+					The first block hash received is an orphan node in the pool
+
+					This also supports clients that (despite the spec) include <from> hash in their
 					response to hashes request. Note that by providing <from> we can link sections
-					without having to wait for the root block of the child section to arrive, so it allows for superior performance
+					without having to wait for the root block of the child section to arrive, so it allows for superior performance.
 				*/
 				plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s) found head block [%s] as root of connecting child section [%s] skipping", peerId, hex(bestpeer.currentBlockHash), hex(hash), sectionhex(entry.section))
 				// record the entry's chain section as child section
@@ -447,9 +507,8 @@ LOOP:
 
 	plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s): %v nodes in new section", peerId, hex(bestpeer.currentBlockHash), len(nodes))
 	/*
-	  handle forks where connecting node is mid-section
-	  by splitting section at fork
-	  no splitting needed if connecting node is head of a section
+	  Handle forks where connecting node is mid-section by splitting section at fork.
+	  No splitting needed if connecting node is head of a section.
 	*/
 	if parent != nil && entry != nil && entry.node != parent.top && len(nodes) > 0 {
 		plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s): fork after %s", peerId, hex(bestpeer.currentBlockHash), hex(hash))
@@ -461,10 +520,7 @@ LOOP:
 		self.status.lock.Unlock()
 	}
 
-	/*
-	  if new section is created, link it to parent/child sections
-	  and launch section process fetching blocks and further hashes
-	*/
+	// If new section is created, link it to parent/child sections.
 	sec = self.linkSections(nodes, parent, child)
 
 	if sec != nil {
@@ -477,11 +533,12 @@ LOOP:
 	self.chainLock.Unlock()
 
 	/*
-		if a blockpool node is reached (parent section is not nil),
+		If a blockpool node is reached (parent section is not nil),
 		activate section (unless our peer is demoted by now).
-		this can be the bottom half of a newly split section in case of a fork.
+		This can be the bottom half of a newly split section in case of a fork.
+
 		bestPeer is nil if we got here after our peer got demoted while processing.
-		in this case no activation should happen
+		In this case no activation should happen
 	*/
 	if parent != nil && !peerswitch {
 		self.activateChain(parent, bestpeer, nil)
@@ -489,9 +546,8 @@ LOOP:
 	}
 
 	/*
-	  if a new section was created,
-	  register section iff head section or no child known
-	  activate it with this peer
+	  If a new section was created, register section iff head section or no child known
+	  Activate it with this peer.
 	*/
 	if sec != nil {
 		// switch on section process (it is paused by switchC)
@@ -502,9 +558,9 @@ LOOP:
 				bestpeer.lock.Unlock()
 			}
 			/*
-			  request next block hashes for parent section here.
-			  but only once, repeating only when bottom block arrives,
-			  otherwise no way to check if it arrived
+			  Request another batch of older block hashes for parent section here.
+			  But only once, repeating only when the section's root block arrives.
+			  Otherwise no way to check if it arrived.
 			*/
 			bestpeer.requestBlockHashes(sec.bottom.hash)
 			plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s): start requesting blocks for section [%s]", peerId, hex(bestpeer.currentBlockHash), sectionhex(sec))
@@ -515,7 +571,7 @@ LOOP:
 		}
 	}
 
-	// if we are processing peer's head section, signal it to headSection process that it is created
+	// If we are processing peer's head section, signal it to headSection process that it is created.
 
 	if headSection {
 		plog.DebugDetailf("AddBlockHashes: peer <%s> (head: %s) head section registered on head section process", peerId, hex(bestpeer.currentBlockHash))
@@ -539,11 +595,13 @@ LOOP:
 /*
 	AddBlock is the entry point for the eth protocol to call when blockMsg is received.
 
-	It has a strict interpretation of the protocol in that if the block received has not been requested, it results in an error
+	It has a strict interpretation of the protocol in that if the block received has not been requested, it results in an error.
 
 	At the same time it is opportunistic in that if a requested block may be provided by any peer.
 
 	The received block is checked for PoW. Only the first PoW-valid block for a hash is considered legit.
+
+	If the block received is the head block of the current best peer, signal it to the head section process
 */
 func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 	hash := block.Hash()
@@ -564,7 +622,6 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 		if sender.currentBlock == nil {
 			plog.Debugf("AddBlock: add head block %s for peer <%s> (head: %s)", hex(hash), peerId, hex(sender.currentBlockHash))
 			sender.setChainInfoFromBlock(block)
-			// sender.currentBlockC <- block
 
 			self.status.lock.Lock()
 			self.status.values.BlockHashes++
@@ -573,6 +630,7 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 			self.status.lock.Unlock()
 		} else {
 			plog.DebugDetailf("AddBlock: head block %s for peer <%s> (head: %s) already known", hex(hash), peerId, hex(sender.currentBlockHash))
+			// signal to head section process
 			sender.currentBlockC <- block
 		}
 	} else {
@@ -591,7 +649,6 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 		sender.lock.Unlock()
 
 		if entry == nil {
-			// penalise peer for sending what we have not asked
 			plog.DebugDetailf("AddBlock: unrequested block %s received from peer <%s> (head: %s)", hex(hash), peerId, hex(sender.currentBlockHash))
 			sender.addError(ErrUnrequestedBlock, "%x", hash)
 
@@ -609,7 +666,7 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 	node.lock.Lock()
 	defer node.lock.Unlock()
 
-	// check if block already present
+	// check if block already received
 	if node.block != nil {
 		plog.DebugDetailf("AddBlock: block %s from peer <%s> (head: %s) already sent by <%s> ", hex(hash), peerId, hex(sender.currentBlockHash), node.blockBy)
 		return
@@ -645,9 +702,9 @@ func (self *BlockPool) AddBlock(block *types.Block, peerId string) {
 }
 
 /*
-  iterates down a chain section by section
-  activating section process on incomplete sections with peer
-  relinking orphaned sections with their parent if root block (and its parent hash) is known)
+  activateChain iterates down a chain section by section.
+  It activates the section process on incomplete sections with peer.
+  It relinks orphaned sections with their parent if root block (and its parent hash) is known.
 */
 func (self *BlockPool) activateChain(sec *section, p *peer, connected map[string]*section) {
 
@@ -666,8 +723,8 @@ LOOP:
 			connected[sec.top.hash.Str()] = sec
 		}
 		/*
-		  we need to relink both complete and incomplete sections
-		  the latter could have been blockHashesRequestsComplete before being delinked from its parent
+		  Need to relink both complete and incomplete sections
+		  An incomplete section could have been blockHashesRequestsComplete before being delinked from its parent.
 		*/
 		if parent == nil {
 			if sec.bottom.block != nil {
@@ -682,7 +739,7 @@ LOOP:
 		}
 		sec = parent
 
-		// stop if peer got demoted
+		// stop if peer got demoted or global quit
 		select {
 		case <-switchC:
 			break LOOP
@@ -693,7 +750,19 @@ LOOP:
 	}
 }
 
-// must run in separate go routine, otherwise
+// check if block's actual TD (calculated after successful insertChain) is identical to TD advertised for peer's head block.
+func (self *BlockPool) checkTD(nodes ...*node) {
+	for _, n := range nodes {
+		if n.td != nil {
+			plog.DebugDetailf("peer td %v =?= block td %v", n.td, n.block.Td)
+			if n.td.Cmp(n.block.Td) != 0 {
+				self.peers.peerError(n.blockBy, ErrIncorrectTD, "on block %x", n.hash)
+			}
+		}
+	}
+}
+
+// requestBlocks must run in separate go routine, otherwise
 // switchpeer -> activateChain -> activate deadlocks on section process select and peers.lock
 func (self *BlockPool) requestBlocks(attempts int, hashes []common.Hash) {
 	self.wg.Add(1)
@@ -720,13 +789,26 @@ func (self *BlockPool) getChild(sec *section) *section {
 func (self *BlockPool) get(hash common.Hash) *entry {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
-	return self.pool[hash.Str()]
+	return self.pool[hash]
 }
 
 func (self *BlockPool) set(hash common.Hash, e *entry) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
-	self.pool[hash.Str()] = e
+	self.pool[hash] = e
+}
+
+// accessor and setter for total difficulty
+func (self *BlockPool) getTD() *big.Int {
+	self.lock.RLock()
+	defer self.lock.RUnlock()
+	return self.td
+}
+
+func (self *BlockPool) setTD(td *big.Int) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	self.td = td
 }
 
 func (self *BlockPool) remove(sec *section) {
@@ -735,7 +817,7 @@ func (self *BlockPool) remove(sec *section) {
 	defer self.lock.Unlock()
 
 	for _, node := range sec.nodes {
-		delete(self.pool, node.hash.Str())
+		delete(self.pool, node.hash)
 	}
 	if sec.initialised && sec.poolRootIndex != 0 {
 		self.status.lock.Lock()
@@ -744,6 +826,7 @@ func (self *BlockPool) remove(sec *section) {
 	}
 }
 
+// get/put for optimised allocation similar to sync.Pool
 func (self *BlockPool) getHashSlice() (s []common.Hash) {
 	select {
 	case s = <-self.hashSlicePool:
@@ -753,7 +836,6 @@ func (self *BlockPool) getHashSlice() (s []common.Hash) {
 	return
 }
 
-// Return returns a Client to the pool.
 func (self *BlockPool) putHashSlice(s []common.Hash) {
 	if len(s) == self.Config.BlockBatchSize {
 		select {
diff --git a/blockpool/blockpool_test.go b/blockpool/blockpool_test.go
index 411779057..9bcd72f04 100644
--- a/blockpool/blockpool_test.go
+++ b/blockpool/blockpool_test.go
@@ -5,10 +5,11 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
-	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/common"
 )
 
+// using the mock framework in blockpool_util_test
+// we test various scenarios here
+
 func TestPeerWithKnownBlock(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
@@ -44,48 +45,6 @@ func TestPeerWithKnownParentBlock(t *testing.T) {
 	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
 }
 
-func TestPeerPromotionByOptionalTdOnBlock(t *testing.T) {
-	test.LogInit()
-	_, blockPool, blockPoolTester := newTestBlockPool(t)
-	blockPoolTester.blockChain[0] = nil
-	blockPoolTester.initRefBlockChain(4)
-	peer0 := blockPoolTester.newPeer("peer0", 2, 2)
-	peer1 := blockPoolTester.newPeer("peer1", 1, 1)
-	peer2 := blockPoolTester.newPeer("peer2", 3, 4)
-
-	blockPool.Start()
-
-	// pool
-	peer0.AddPeer()
-	peer0.serveBlocks(1, 2)
-	best := peer1.AddPeer()
-	// this tests that peer1 is not promoted over peer0 yet
-	if best {
-		t.Errorf("peer1 (TD=1) should not be set as best")
-	}
-	best = peer2.AddPeer()
-	peer2.serveBlocks(3, 4)
-	peer2.serveBlockHashes(4, 3, 2, 1)
-	hashes := blockPoolTester.hashPool.IndexesToHashes([]int{2, 3})
-	peer1.waitBlocksRequests(3)
-	blockPool.AddBlock(&types.Block{
-		HeaderHash:       common.Bytes(hashes[1]),
-		ParentHeaderHash: common.Bytes(hashes[0]),
-		Td:               common.Big3,
-	}, "peer1")
-
-	blockPool.RemovePeer("peer2")
-	if blockPool.peers.best.id != "peer1" {
-		t.Errorf("peer1 (TD=3) should be set as best")
-	}
-	peer1.serveBlocks(0, 1, 2)
-
-	blockPool.Wait(waitTimeout)
-	blockPool.Stop()
-	blockPoolTester.refBlockChain[4] = []int{}
-	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
-}
-
 func TestSimpleChain(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
@@ -94,7 +53,7 @@ func TestSimpleChain(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 2)
+	peer1 := blockPoolTester.newPeer("peer1", 2, 2)
 	peer1.AddPeer()
 	peer1.serveBlocks(1, 2)
 	go peer1.serveBlockHashes(2, 1, 0)
@@ -114,7 +73,7 @@ func TestChainConnectingWithParentHash(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1 := blockPoolTester.newPeer("peer1", 3, 3)
 	peer1.AddPeer()
 	go peer1.serveBlocks(2, 3)
 	go peer1.serveBlockHashes(3, 2, 1)
@@ -134,7 +93,7 @@ func TestMultiSectionChain(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 5)
+	peer1 := blockPoolTester.newPeer("peer1", 5, 5)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(4, 5)
@@ -156,14 +115,17 @@ func TestNewBlocksOnPartialChain(t *testing.T) {
 	blockPoolTester.initRefBlockChain(7)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 5)
+	peer1 := blockPoolTester.newPeer("peer1", 5, 5)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[5] = 5
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(4, 5) // partially complete section
 	go peer1.serveBlockHashes(5, 4, 3)
 	peer1.serveBlocks(3, 4) // partially complete section
+
 	// peer1 found new blocks
-	peer1.td = 2
+	peer1.td = 7
 	peer1.currentBlock = 7
 	peer1.AddPeer()
 	peer1.sendBlocks(6, 7)
@@ -172,7 +134,6 @@ func TestNewBlocksOnPartialChain(t *testing.T) {
 	go peer1.serveBlocks(5, 6)
 	go peer1.serveBlockHashes(3, 2, 1) // tests that hash request from known chain root is remembered
 	peer1.serveBlocks(0, 1, 2)
-	// blockPool.RemovePeer("peer1")
 
 	blockPool.Wait(waitTimeout)
 	blockPool.Stop()
@@ -188,16 +149,15 @@ func TestPeerSwitchUp(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 6)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 7)
+	peer1 := blockPoolTester.newPeer("peer1", 6, 6)
+	peer2 := blockPoolTester.newPeer("peer2", 7, 7)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(5, 6)
 	go peer1.serveBlockHashes(6, 5, 4, 3) //
 	peer1.serveBlocks(2, 3)               // section partially complete, block 3 will be preserved after peer demoted
 	peer2.AddPeer()                       // peer2 is promoted as best peer, peer1 is demoted
-	go peer2.serveBlocks(6, 7)
-	// go peer2.serveBlockHashes(7, 6)       //
+	go peer2.serveBlocks(6, 7)            //
 	go peer2.serveBlocks(4, 5)            // tests that block request for earlier section is remembered
 	go peer1.serveBlocks(3, 4)            // tests that connecting section by demoted peer is remembered and blocks are accepted from demoted peer
 	go peer2.serveBlockHashes(3, 2, 1, 0) // tests that known chain section is activated, hash requests from 3 is remembered
@@ -216,8 +176,8 @@ func TestPeerSwitchDownOverlapSectionWithoutRootBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(6)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 4)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 4, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)                  // partially complete, section will be preserved
@@ -242,8 +202,8 @@ func TestPeerSwitchDownOverlapSectionWithRootBlock(t *testing.T) {
 	blockPoolTester.initRefBlockChain(6)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 4)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 4, 4)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)                  // partially complete, section will be preserved
@@ -269,8 +229,8 @@ func TestPeerSwitchDownDisjointSection(t *testing.T) {
 	blockPoolTester.initRefBlockChain(3)
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer1 := blockPoolTester.newPeer("peer1", 3, 3)
+	peer2 := blockPoolTester.newPeer("peer2", 6, 6)
 
 	peer2.AddPeer()
 	peer2.serveBlocks(5, 6)            // partially complete, section will be preserved
@@ -297,8 +257,8 @@ func TestPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 2, 11)
-	peer2 := blockPoolTester.newPeer("peer2", 1, 8)
+	peer1 := blockPoolTester.newPeer("peer1", 11, 11)
+	peer2 := blockPoolTester.newPeer("peer2", 8, 8)
 
 	peer2.AddPeer()
 	go peer2.serveBlocks(7, 8)
@@ -328,9 +288,10 @@ func TestForkSimple(t *testing.T) {
 	delete(blockPoolTester.refBlockChain, 6)
 
 	blockPool.Start()
-
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
@@ -363,9 +324,10 @@ func TestForkSwitchBackByNewBlocks(t *testing.T) {
 	delete(blockPoolTester.refBlockChain, 6)
 
 	blockPool.Start()
-
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)               //
@@ -378,7 +340,7 @@ func TestForkSwitchBackByNewBlocks(t *testing.T) {
 	peer2.serveBlocks(1, 2, 3, 4, 5)         //
 
 	// peer1 finds new blocks
-	peer1.td = 3
+	peer1.td = 11
 	peer1.currentBlock = 11
 	peer1.AddPeer()
 	go peer1.serveBlocks(10, 11)
@@ -410,8 +372,14 @@ func TestForkSwitchBackByPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
@@ -448,14 +416,17 @@ func TestForkCompleteSectionSwitchBackByPeerSwitchBack(t *testing.T) {
 
 	blockPool.Start()
 
-	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[6] = 10
+
+	peer1 := blockPoolTester.newPeer("peer1", 9, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 10, 6)
 
 	peer1.AddPeer()
 	go peer1.serveBlocks(8, 9)
 	go peer1.serveBlockHashes(9, 8, 7)
-	peer1.serveBlocks(3, 7, 8) // make sure this section is complete
-	time.Sleep(1 * time.Second)
+	peer1.serveBlocks(3, 7, 8)               // make sure this section is complete
+	time.Sleep(1 * time.Second)              //
 	go peer1.serveBlockHashes(7, 3, 2)       // block 3/7 is section boundary
 	peer1.serveBlocks(2, 3)                  // partially complete sections block 2 missing
 	peer2.AddPeer()                          //
@@ -463,8 +434,7 @@ func TestForkCompleteSectionSwitchBackByPeerSwitchBack(t *testing.T) {
 	go peer2.serveBlockHashes(6, 5, 4, 3, 2) // peer2 forks on block 3
 	peer2.serveBlocks(2, 3, 4, 5)            // block 2 still missing.
 	blockPool.RemovePeer("peer2")            // peer2 disconnects, peer1 is promoted again as best peer
-	// peer1.serveBlockHashes(7, 3)             // tests that hash request from fork root is remembered even though section process completed
-	go peer1.serveBlockHashes(2, 1, 0) //
+	go peer1.serveBlockHashes(2, 1, 0)       //
 	peer1.serveBlocks(0, 1, 2)
 
 	blockPool.Wait(waitTimeout)
diff --git a/blockpool/blockpool_util_test.go b/blockpool/blockpool_util_test.go
index 9ac996bca..be14fbae8 100644
--- a/blockpool/blockpool_util_test.go
+++ b/blockpool/blockpool_util_test.go
@@ -8,9 +8,10 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/errs"
-	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/pow"
 )
 
@@ -38,6 +39,8 @@ type blockPoolTester struct {
 	blockChain        blockChain
 	blockPool         *BlockPool
 	t                 *testing.T
+	chainEvents       *event.TypeMux
+	tds               map[int]int
 }
 
 func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *BlockPool, b *blockPoolTester) {
@@ -48,8 +51,9 @@ func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *Blo
 		blockChain:        make(blockChain),
 		refBlockChain:     make(blockChain),
 		blocksRequestsMap: make(map[int]bool),
+		chainEvents:       &event.TypeMux{},
 	}
-	b.blockPool = New(b.hasBlock, b.insertChain, b.verifyPoW)
+	b.blockPool = New(b.hasBlock, b.insertChain, b.verifyPoW, b.chainEvents, common.Big0)
 	blockPool = b.blockPool
 	blockPool.Config.BlockHashesRequestInterval = testBlockHashesRequestInterval
 	blockPool.Config.BlocksRequestInterval = testBlocksRequestInterval
@@ -57,22 +61,24 @@ func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *Blo
 }
 
 func (self *blockPoolTester) Errorf(format string, params ...interface{}) {
-	fmt.Printf(format+"\n", params...)
+	// fmt.Printf(format+"\n", params...)
 	self.t.Errorf(format, params...)
 }
 
 // blockPoolTester implements the 3 callbacks needed by the blockPool:
-// hasBlock, insetChain, verifyPoW
-func (self *blockPoolTester) hasBlock(block []byte) (ok bool) {
+// hasBlock, insetChain, verifyPoW as well as provides the eventer
+// to subscribe to head insertions
+func (self *blockPoolTester) hasBlock(block common.Hash) (ok bool) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
-	indexes := self.hashPool.HashesToIndexes([][]byte{block})
+	indexes := self.hashPool.HashesToIndexes([]common.Hash{block})
 	i := indexes[0]
 	_, ok = self.blockChain[i]
-	fmt.Printf("has block %v (%x...): %v\n", i, block[0:4], ok)
+	// fmt.Printf("has block %v (%x...): %v\n", i, block[0:4], ok)
 	return
 }
 
+// mock insertChain relies on refBlockChain to determine block validity
 func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -80,13 +86,21 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	var children, refChildren []int
 	var ok bool
 	for _, block := range blocks {
-		child = self.hashPool.HashesToIndexes([][]byte{block.Hash()})[0]
+		child = self.hashPool.HashesToIndexes([]common.Hash{block.Hash()})[0]
+		var td int
+		if self.tds != nil {
+			td, ok = self.tds[child]
+		}
+		if !ok {
+			td = child
+		}
+		block.Td = big.NewInt(int64(td))
 		_, ok = self.blockChain[child]
 		if ok {
-			fmt.Printf("block %v already in blockchain\n", child)
+			// fmt.Printf("block %v already in blockchain\n", child)
 			continue // already in chain
 		}
-		parent = self.hashPool.HashesToIndexes([][]byte{block.ParentHeaderHash})[0]
+		parent = self.hashPool.HashesToIndexes([]common.Hash{block.ParentHeaderHash})[0]
 		children, ok = self.blockChain[parent]
 		if !ok {
 			return fmt.Errorf("parent %v not in blockchain ", parent)
@@ -108,7 +122,6 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 		}
 		if ok {
 			// accept any blocks if parent not in refBlockChain
-			fmt.Errorf("blockchain insert %v -> %v\n", parent, child)
 			self.blockChain[parent] = append(children, child)
 			self.blockChain[child] = nil
 		}
@@ -116,6 +129,7 @@ func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
 	return nil
 }
 
+// mock soft block validation always succeeds
 func (self *blockPoolTester) verifyPoW(pblock pow.Block) bool {
 	return true
 }
@@ -124,12 +138,12 @@ func (self *blockPoolTester) verifyPoW(pblock pow.Block) bool {
 func (self *blockPoolTester) checkBlockChain(blockChain map[int][]int) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
-	for k, v := range self.blockChain {
-		fmt.Printf("got: %v -> %v\n", k, v)
-	}
-	for k, v := range blockChain {
-		fmt.Printf("expected: %v -> %v\n", k, v)
-	}
+	// for k, v := range self.blockChain {
+	// 	fmt.Printf("got: %v -> %v\n", k, v)
+	// }
+	// for k, v := range blockChain {
+	// 	fmt.Printf("expected: %v -> %v\n", k, v)
+	// }
 	if len(blockChain) != len(self.blockChain) {
 		self.Errorf("blockchain incorrect (zlength differ)")
 	}
@@ -141,24 +155,24 @@ func (self *blockPoolTester) checkBlockChain(blockChain map[int][]int) {
 	}
 }
 
-//
-
 // peerTester provides the peer callbacks for the blockPool
 // it registers actual callbacks so that the result can be compared to desired behaviour
 // provides helper functions to mock the protocol calls to the blockPool
 type peerTester struct {
+	// containers to record request and error callbacks
 	blockHashesRequests []int
 	blocksRequests      [][]int
 	blocksRequestsMap   map[int]bool
 	peerErrors          []int
-	blockPool           *BlockPool
-	hashPool            *test.TestHashPool
-	lock                sync.RWMutex
-	bt                  *blockPoolTester
-	id                  string
-	td                  int
-	currentBlock        int
-	t                   *testing.T
+
+	blockPool    *BlockPool
+	hashPool     *test.TestHashPool
+	lock         sync.RWMutex
+	bt           *blockPoolTester
+	id           string
+	td           int
+	currentBlock int
+	t            *testing.T
 }
 
 // peerTester constructor takes hashPool and blockPool from the blockPoolTester
@@ -176,7 +190,7 @@ func (self *blockPoolTester) newPeer(id string, td int, cb int) *peerTester {
 }
 
 func (self *peerTester) Errorf(format string, params ...interface{}) {
-	fmt.Printf(format+"\n", params...)
+	// fmt.Printf(format+"\n", params...)
 	self.t.Errorf(format, params...)
 }
 
@@ -211,6 +225,7 @@ func (self *peerTester) checkBlockHashesRequests(blocksHashesRequests ...int) {
 
 // waiter function used by peer.serveBlocks
 // blocking until requests appear
+// this mocks proper wire protocol behaviour
 // since block requests are sent to any random peers
 // block request map is shared between peers
 // times out after waitTimeout
@@ -220,7 +235,7 @@ func (self *peerTester) waitBlocksRequests(blocksRequest ...int) {
 	for {
 		self.lock.RLock()
 		r := self.blocksRequestsMap
-		fmt.Printf("[%s] blocks request check %v (%v)\n", self.id, rr, r)
+		// fmt.Printf("[%s] blocks request check %v (%v)\n", self.id, rr, r)
 		i := 0
 		for i = 0; i < len(rr); i++ {
 			_, ok := r[rr[i]]
@@ -243,6 +258,7 @@ func (self *peerTester) waitBlocksRequests(blocksRequest ...int) {
 
 // waiter function used by peer.serveBlockHashes
 // blocking until requests appear
+// this mocks proper wire protocol behaviour
 // times out after a period
 func (self *peerTester) waitBlockHashesRequests(blocksHashesRequest int) {
 	timeout := time.After(waitTimeout)
@@ -251,7 +267,7 @@ func (self *peerTester) waitBlockHashesRequests(blocksHashesRequest int) {
 		self.lock.RLock()
 		r := self.blockHashesRequests
 		self.lock.RUnlock()
-		fmt.Printf("[%s] block hash request check %v (%v)\n", self.id, rr, r)
+		// fmt.Printf("[%s] block hash request check %v (%v)\n", self.id, rr, r)
 		for ; i < len(r); i++ {
 			if rr == r[i] {
 				return
@@ -274,24 +290,26 @@ func (self *blockPoolTester) initRefBlockChain(n int) {
 
 // peerTester functions that mimic protocol calls to the blockpool
 //  registers the peer with the blockPool
-func (self *peerTester) AddPeer() bool {
+func (self *peerTester) AddPeer() (best bool) {
 	hash := self.hashPool.IndexesToHashes([]int{self.currentBlock})[0]
-	return self.blockPool.AddPeer(big.NewInt(int64(self.td)), hash, self.id, self.requestBlockHashes, self.requestBlocks, self.peerError)
+	best, _ = self.blockPool.AddPeer(big.NewInt(int64(self.td)), hash, self.id, self.requestBlockHashes, self.requestBlocks, self.peerError)
+	return
 }
 
 // peer sends blockhashes if and when gets a request
 func (self *peerTester) serveBlockHashes(indexes ...int) {
-	fmt.Printf("ready to serve block hashes %v\n", indexes)
+	// fmt.Printf("ready to serve block hashes %v\n", indexes)
 
 	self.waitBlockHashesRequests(indexes[0])
 	self.sendBlockHashes(indexes...)
 }
 
+// peer sends blockhashes not waiting for request
 func (self *peerTester) sendBlockHashes(indexes ...int) {
-	fmt.Printf("adding block hashes %v\n", indexes)
+	// fmt.Printf("adding block hashes %v\n", indexes)
 	hashes := self.hashPool.IndexesToHashes(indexes)
 	i := 1
-	next := func() (hash []byte, ok bool) {
+	next := func() (hash common.Hash, ok bool) {
 		if i < len(hashes) {
 			hash = hashes[i]
 			ok = true
@@ -303,28 +321,30 @@ func (self *peerTester) sendBlockHashes(indexes ...int) {
 }
 
 // peer sends blocks if and when there is a request
-// (in the shared request store, not necessarily to a person)
+// (in the shared request store, not necessarily to a specific peer)
 func (self *peerTester) serveBlocks(indexes ...int) {
-	fmt.Printf("ready to serve blocks %v\n", indexes[1:])
+	// fmt.Printf("ready to serve blocks %v\n", indexes[1:])
 	self.waitBlocksRequests(indexes[1:]...)
 	self.sendBlocks(indexes...)
 }
 
+// peer sends blocks not waiting for request
 func (self *peerTester) sendBlocks(indexes ...int) {
-	fmt.Printf("adding blocks %v \n", indexes)
+	// fmt.Printf("adding blocks %v \n", indexes)
 	hashes := self.hashPool.IndexesToHashes(indexes)
 	for i := 1; i < len(hashes); i++ {
-		fmt.Printf("adding block %v %x\n", indexes[i], hashes[i][:4])
-		self.blockPool.AddBlock(&types.Block{HeaderHash: common.Bytes(hashes[i]), ParentHeaderHash: common.Bytes(hashes[i-1])}, self.id)
+		// fmt.Printf("adding block %v %x\n", indexes[i], hashes[i][:4])
+		self.blockPool.AddBlock(&types.Block{HeaderHash: hashes[i], ParentHeaderHash: hashes[i-1]}, self.id)
 	}
 }
 
-// peer callbacks
-// -1 is special: not found (a hash never seen)
+// the 3 mock peer callbacks
+
 // records block hashes requests by the blockPool
-func (self *peerTester) requestBlockHashes(hash []byte) error {
-	indexes := self.hashPool.HashesToIndexes([][]byte{hash})
-	fmt.Printf("[%s] block hash request %v %x\n", self.id, indexes[0], hash[:4])
+// -1 is special: not found (a hash never seen)
+func (self *peerTester) requestBlockHashes(hash common.Hash) error {
+	indexes := self.hashPool.HashesToIndexes([]common.Hash{hash})
+	// fmt.Printf("[%s] block hash request %v %x\n", self.id, indexes[0], hash[:4])
 	self.lock.Lock()
 	defer self.lock.Unlock()
 	self.blockHashesRequests = append(self.blockHashesRequests, indexes[0])
@@ -332,9 +352,9 @@ func (self *peerTester) requestBlockHashes(hash []byte) error {
 }
 
 // records block requests by the blockPool
-func (self *peerTester) requestBlocks(hashes [][]byte) error {
+func (self *peerTester) requestBlocks(hashes []common.Hash) error {
 	indexes := self.hashPool.HashesToIndexes(hashes)
-	fmt.Printf("blocks request %v %x...\n", indexes, hashes[0][:4])
+	// fmt.Printf("blocks request %v %x...\n", indexes, hashes[0][:4])
 	self.bt.reqlock.Lock()
 	defer self.bt.reqlock.Unlock()
 	self.blocksRequests = append(self.blocksRequests, indexes)
@@ -347,4 +367,7 @@ func (self *peerTester) requestBlocks(hashes [][]byte) error {
 // records the error codes of all the peerErrors found the blockPool
 func (self *peerTester) peerError(err *errs.Error) {
 	self.peerErrors = append(self.peerErrors, err.Code)
+	if err.Fatal() {
+		self.blockPool.RemovePeer(self.id)
+	}
 }
diff --git a/blockpool/config_test.go b/blockpool/config_test.go
index d5540c864..e1ce31f27 100644
--- a/blockpool/config_test.go
+++ b/blockpool/config_test.go
@@ -5,11 +5,12 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/event"
 )
 
 func TestBlockPoolConfig(t *testing.T) {
 	test.LogInit()
-	blockPool := &BlockPool{Config: &Config{}}
+	blockPool := &BlockPool{Config: &Config{}, chainEvents: &event.TypeMux{}}
 	blockPool.Start()
 	c := blockPool.Config
 	test.CheckInt("BlockHashesBatchSize", c.BlockHashesBatchSize, blockHashesBatchSize, t)
@@ -21,12 +22,14 @@ func TestBlockPoolConfig(t *testing.T) {
 	test.CheckDuration("BlockHashesTimeout", c.BlockHashesTimeout, blockHashesTimeout, t)
 	test.CheckDuration("BlocksTimeout", c.BlocksTimeout, blocksTimeout, t)
 	test.CheckDuration("IdleBestPeerTimeout", c.IdleBestPeerTimeout, idleBestPeerTimeout, t)
+	test.CheckDuration("PeerSuspensionInterval", c.PeerSuspensionInterval, peerSuspensionInterval, t)
+	test.CheckDuration("StatusUpdateInterval", c.StatusUpdateInterval, statusUpdateInterval, t)
 }
 
 func TestBlockPoolOverrideConfig(t *testing.T) {
 	test.LogInit()
-	blockPool := &BlockPool{Config: &Config{}}
-	c := &Config{128, 32, 1, 0, 300 * time.Millisecond, 100 * time.Millisecond, 90 * time.Second, 0, 30 * time.Second}
+	blockPool := &BlockPool{Config: &Config{}, chainEvents: &event.TypeMux{}}
+	c := &Config{128, 32, 1, 0, 300 * time.Millisecond, 100 * time.Millisecond, 90 * time.Second, 0, 30 * time.Second, 30 * time.Second, 4 * time.Second}
 
 	blockPool.Config = c
 	blockPool.Start()
@@ -39,4 +42,6 @@ func TestBlockPoolOverrideConfig(t *testing.T) {
 	test.CheckDuration("BlockHashesTimeout", c.BlockHashesTimeout, 90*time.Second, t)
 	test.CheckDuration("BlocksTimeout", c.BlocksTimeout, blocksTimeout, t)
 	test.CheckDuration("IdleBestPeerTimeout", c.IdleBestPeerTimeout, 30*time.Second, t)
+	test.CheckDuration("PeerSuspensionInterval", c.PeerSuspensionInterval, 30*time.Second, t)
+	test.CheckDuration("StatusUpdateInterval", c.StatusUpdateInterval, 4*time.Second, t)
 }
diff --git a/blockpool/errors_test.go b/blockpool/errors_test.go
index 65a161233..350d6daef 100644
--- a/blockpool/errors_test.go
+++ b/blockpool/errors_test.go
@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/pow"
 )
@@ -45,7 +46,7 @@ func TestVerifyPoW(t *testing.T) {
 	first := false
 	blockPoolTester.blockPool.verifyPoW = func(b pow.Block) bool {
 		bb, _ := b.(*types.Block)
-		indexes := blockPoolTester.hashPool.HashesToIndexes([][]byte{bb.Hash()})
+		indexes := blockPoolTester.hashPool.HashesToIndexes([]common.Hash{bb.Hash()})
 		if indexes[0] == 2 && !first {
 			first = true
 			return false
@@ -92,7 +93,6 @@ func TestUnrequestedBlock(t *testing.T) {
 	peer1.AddPeer()
 	peer1.sendBlocks(1, 2)
 
-	// blockPool.Wait(waitTimeout)
 	blockPool.Stop()
 	if len(peer1.peerErrors) == 1 {
 		if peer1.peerErrors[0] != ErrUnrequestedBlock {
@@ -122,3 +122,60 @@ func TestErrInsufficientChainInfo(t *testing.T) {
 		t.Errorf("expected %v error, got %v", ErrInsufficientChainInfo, peer1.peerErrors)
 	}
 }
+
+func TestIncorrectTD(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(3)
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	go peer1.serveBlocks(2, 3)
+	go peer1.serveBlockHashes(3, 2, 1, 0)
+	peer1.serveBlocks(0, 1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[3] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
+	if len(peer1.peerErrors) == 1 {
+		if peer1.peerErrors[0] != ErrIncorrectTD {
+			t.Errorf("wrong error, got %v, expected %v", peer1.peerErrors[0], ErrIncorrectTD)
+		}
+	} else {
+		t.Errorf("expected %v error, got %v", ErrIncorrectTD, peer1.peerErrors)
+	}
+}
+
+func TestPeerSuspension(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPool.Config.PeerSuspensionInterval = 100 * time.Millisecond
+
+	blockPool.Start()
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 3)
+	peer1.AddPeer()
+	blockPool.peers.peerError("peer1", 0, "")
+	bestpeer, _ := blockPool.peers.getPeer("peer1")
+	if bestpeer != nil {
+		t.Errorf("peer1 not removed on error")
+	}
+	peer1.AddPeer()
+	bestpeer, _ = blockPool.peers.getPeer("peer1")
+	if bestpeer != nil {
+		t.Errorf("peer1 not removed on reconnect")
+	}
+	time.Sleep(100 * time.Millisecond)
+	peer1.AddPeer()
+	bestpeer, _ = blockPool.peers.getPeer("peer1")
+	if bestpeer == nil {
+		t.Errorf("peer1 not connected after PeerSuspensionInterval")
+	}
+	// blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+
+}
diff --git a/blockpool/peers.go b/blockpool/peers.go
index d94d6ac46..80168b206 100644
--- a/blockpool/peers.go
+++ b/blockpool/peers.go
@@ -12,6 +12,7 @@ import (
 	"github.com/ethereum/go-ethereum/errs"
 )
 
+// the blockpool's model of a peer
 type peer struct {
 	lock sync.RWMutex
 
@@ -47,6 +48,8 @@ type peer struct {
 	blocksRequestTimer      <-chan time.Time
 	suicideC                <-chan time.Time
 
+	addToBlacklist func(id string)
+
 	idle bool
 }
 
@@ -55,11 +58,12 @@ type peer struct {
 type peers struct {
 	lock sync.RWMutex
 
-	bp     *BlockPool
-	errors *errs.Errors
-	peers  map[string]*peer
-	best   *peer
-	status *status
+	bp        *BlockPool
+	errors    *errs.Errors
+	peers     map[string]*peer
+	best      *peer
+	status    *status
+	blacklist map[string]time.Time
 }
 
 // peer constructor
@@ -84,26 +88,48 @@ func (self *peers) newPeer(
 		headSectionC:       make(chan *section),
 		bp:                 self.bp,
 		idle:               true,
+		addToBlacklist:     self.addToBlacklist,
 	}
 	// at creation the peer is recorded in the peer pool
 	self.peers[id] = p
 	return
 }
 
-// dispatches an error to a peer if still connected
+// dispatches an error to a peer if still connected, adds it to the blacklist
 func (self *peers) peerError(id string, code int, format string, params ...interface{}) {
 	self.lock.RLock()
-	defer self.lock.RUnlock()
 	peer, ok := self.peers[id]
+	self.lock.RUnlock()
 	if ok {
 		peer.addError(code, format, params)
 	}
-	// blacklisting comes here
+	self.addToBlacklist(id)
+}
+
+// record time of offence in blacklist to implement suspension for PeerSuspensionInterval
+func (self *peers) addToBlacklist(id string) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	self.blacklist[id] = time.Now()
+}
+
+// suspended checks if peer is still suspended
+func (self *peers) suspended(id string) (s bool) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	if suspendedAt, ok := self.blacklist[id]; ok {
+		if s = suspendedAt.Add(self.bp.Config.PeerSuspensionInterval).After(time.Now()); !s {
+			// no longer suspended, delete entry
+			delete(self.blacklist, id)
+		}
+	}
+	return
 }
 
 func (self *peer) addError(code int, format string, params ...interface{}) {
 	err := self.errors.New(code, format, params...)
 	self.peerError(err)
+	self.addToBlacklist(self.id)
 }
 
 func (self *peer) setChainInfo(td *big.Int, c common.Hash) {
@@ -138,8 +164,8 @@ func (self *peer) setChainInfoFromBlock(block *types.Block) {
 	}()
 }
 
+// distribute block request among known peers
 func (self *peers) requestBlocks(attempts int, hashes []common.Hash) {
-	// distribute block request among known peers
 	self.lock.RLock()
 	defer self.lock.RUnlock()
 	peerCount := len(self.peers)
@@ -174,7 +200,9 @@ func (self *peers) requestBlocks(attempts int, hashes []common.Hash) {
 }
 
 // addPeer implements the logic for blockpool.AddPeer
-// returns true iff peer is promoted as best peer in the pool
+// returns 2 bool values
+// 1. true iff peer is promoted as best peer in the pool
+// 2. true iff peer is still suspended
 func (self *peers) addPeer(
 	td *big.Int,
 	currentBlockHash common.Hash,
@@ -182,16 +210,23 @@ func (self *peers) addPeer(
 	requestBlockHashes func(common.Hash) error,
 	requestBlocks func([]common.Hash) error,
 	peerError func(*errs.Error),
-) (best bool) {
+) (best bool, suspended bool) {
 
 	var previousBlockHash common.Hash
+	if self.suspended(id) {
+		suspended = true
+		return
+	}
 	self.lock.Lock()
 	p, found := self.peers[id]
 	if found {
+		// when called on an already connected peer, it means a newBlockMsg is received
+		// peer head info is updated
 		if p.currentBlockHash != currentBlockHash {
 			previousBlockHash = p.currentBlockHash
 			plog.Debugf("addPeer: Update peer <%s> with td %v and current block %s (was %v)", id, td, hex(currentBlockHash), hex(previousBlockHash))
 			p.setChainInfo(td, currentBlockHash)
+
 			self.status.lock.Lock()
 			self.status.values.NewBlocks++
 			self.status.lock.Unlock()
@@ -209,11 +244,11 @@ func (self *peers) addPeer(
 	}
 	self.lock.Unlock()
 
-	// check peer current head
+	// check if peer's current head block is known
 	if self.bp.hasBlock(currentBlockHash) {
 		// peer not ahead
 		plog.Debugf("addPeer: peer <%v> with td %v and current block %s is behind", id, td, hex(currentBlockHash))
-		return false
+		return false, false
 	}
 
 	if self.best == p {
@@ -229,7 +264,8 @@ func (self *peers) addPeer(
 		}
 		best = true
 	} else {
-		currentTD := common.Big0
+		// baseline is our own TD
+		currentTD := self.bp.getTD()
 		if self.best != nil {
 			currentTD = self.best.td
 		}
@@ -237,7 +273,7 @@ func (self *peers) addPeer(
 			self.status.lock.Lock()
 			self.status.bestPeers[p.id]++
 			self.status.lock.Unlock()
-			plog.Debugf("addPeer: peer <%v> promoted best peer", id)
+			plog.Debugf("addPeer: peer <%v> (td: %v > current td %v) promoted best peer", id, td, currentTD)
 			self.bp.switchPeer(self.best, p)
 			self.best = p
 			best = true
@@ -257,13 +293,13 @@ func (self *peers) removePeer(id string) {
 	}
 
 	delete(self.peers, id)
-	plog.Debugf("addPeer: remove peer <%v>", id)
+	plog.Debugf("addPeer: remove peer <%v> (td: %v)", id, p.td)
 
 	// if current best peer is removed, need to find a better one
 	if self.best == p {
 		var newp *peer
-		// FIXME: own TD
-		max := common.Big0
+		// only peers that are ahead of us are considered
+		max := self.bp.getTD()
 		// peer with the highest self-acclaimed TD is chosen
 		for _, pp := range self.peers {
 			if pp.td.Cmp(max) > 0 {
@@ -275,7 +311,7 @@ func (self *peers) removePeer(id string) {
 			self.status.lock.Lock()
 			self.status.bestPeers[p.id]++
 			self.status.lock.Unlock()
-			plog.Debugf("addPeer: peer <%v> with td %v promoted best peer", newp.id, newp.td)
+			plog.Debugf("addPeer: peer <%v> (td: %v) promoted best peer", newp.id, newp.td)
 		} else {
 			plog.Warnln("addPeer: no suitable peers found")
 		}
@@ -288,6 +324,7 @@ func (self *peers) removePeer(id string) {
 func (self *BlockPool) switchPeer(oldp, newp *peer) {
 
 	// first quit AddBlockHashes, requestHeadSection and activateChain
+	// by closing the old peer's switchC channel
 	if oldp != nil {
 		plog.DebugDetailf("<%s> quit peer processes", oldp.id)
 		close(oldp.switchC)
@@ -340,11 +377,12 @@ func (self *BlockPool) switchPeer(oldp, newp *peer) {
 	// newp activating section process changes the quit channel for this reason
 	if oldp != nil {
 		plog.DebugDetailf("<%s> quit section processes", oldp.id)
-		//
 		close(oldp.idleC)
 	}
 }
 
+// getPeer looks up peer by id, returns peer and a bool value
+// that is true iff peer is current best peer
 func (self *peers) getPeer(id string) (p *peer, best bool) {
 	self.lock.RLock()
 	defer self.lock.RUnlock()
@@ -355,6 +393,8 @@ func (self *peers) getPeer(id string) (p *peer, best bool) {
 	return
 }
 
+// head section process
+
 func (self *peer) handleSection(sec *section) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
@@ -426,6 +466,11 @@ func (self *peer) getBlockHashes() {
 			self.addError(ErrInvalidBlock, "%v", err)
 			self.bp.status.badPeers[self.id]++
 		} else {
+			if self.currentBlock.Td != nil {
+				if self.td.Cmp(self.currentBlock.Td) != 0 {
+					self.addError(ErrIncorrectTD, "on block %x", self.currentBlockHash)
+				}
+			}
 			headKey := self.parentHash.Str()
 			height := self.bp.status.chain[headKey] + 1
 			self.bp.status.chain[self.currentBlockHash.Str()] = height
@@ -445,6 +490,7 @@ func (self *peer) getBlockHashes() {
 					block:   self.currentBlock,
 					hashBy:  self.id,
 					blockBy: self.id,
+					td:      self.td,
 				}
 				self.bp.newSection([]*node{n}).activate(self)
 			} else {
@@ -485,7 +531,7 @@ func (self *peer) run() {
 LOOP:
 	for {
 		select {
-		// to minitor section process behaviou
+		// to minitor section process behaviour
 		case <-ping.C:
 			plog.Debugf("HeadSection: <%s> section with head %s, idle: %v", self.id, hex(self.currentBlockHash), self.idle)
 
@@ -538,7 +584,7 @@ LOOP:
 
 		// quit
 		case <-quit:
-			self.peerError(self.bp.peers.errors.New(ErrIdleTooLong, "timed out without providing new blocks (td: %v, head: %s)...quitting", self.td, self.currentBlockHash))
+			self.peerError(self.bp.peers.errors.New(ErrIdleTooLong, "timed out without providing new blocks (td: %v, head: %s)...quitting", self.td, hex(self.currentBlockHash)))
 
 			self.bp.status.lock.Lock()
 			self.bp.status.badPeers[self.id]++
diff --git a/blockpool/peers_test.go b/blockpool/peers_test.go
index e53d7160b..beeb0ad1d 100644
--- a/blockpool/peers_test.go
+++ b/blockpool/peers_test.go
@@ -3,17 +3,21 @@ package blockpool
 import (
 	"math/big"
 	"testing"
+	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
 )
 
 // the actual tests
 func TestAddPeer(t *testing.T) {
 	test.LogInit()
 	_, blockPool, blockPoolTester := newTestBlockPool(t)
-	peer0 := blockPoolTester.newPeer("peer0", 1, 0)
-	peer1 := blockPoolTester.newPeer("peer1", 2, 1)
-	peer2 := blockPoolTester.newPeer("peer2", 3, 2)
+	peer0 := blockPoolTester.newPeer("peer0", 1, 1)
+	peer1 := blockPoolTester.newPeer("peer1", 2, 2)
+	peer2 := blockPoolTester.newPeer("peer2", 3, 3)
 	var bestpeer *peer
 
 	blockPool.Start()
@@ -34,7 +38,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer2" {
 		t.Errorf("peer2 (TD=3) not set as best")
 	}
-	peer2.waitBlocksRequests(2)
+	peer2.waitBlocksRequests(3)
 
 	best = peer1.AddPeer()
 	if best {
@@ -48,7 +52,7 @@ func TestAddPeer(t *testing.T) {
 	}
 
 	peer2.td = 4
-	peer2.currentBlock = 3
+	peer2.currentBlock = 4
 	best = peer2.AddPeer()
 	if !best {
 		t.Errorf("peer2 (TD=4) not accepted as best")
@@ -59,10 +63,10 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.td.Cmp(big.NewInt(int64(4))) != 0 {
 		t.Errorf("peer2 TD not updated")
 	}
-	peer2.waitBlocksRequests(3)
+	peer2.waitBlocksRequests(4)
 
 	peer1.td = 3
-	peer1.currentBlock = 2
+	peer1.currentBlock = 3
 	best = peer1.AddPeer()
 	if best {
 		t.Errorf("peer1 (TD=3) should not be set as best")
@@ -84,7 +88,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer1" {
 		t.Errorf("existing peer1 (TD=3) should be set as best peer")
 	}
-	peer1.waitBlocksRequests(2)
+	peer1.waitBlocksRequests(3)
 
 	blockPool.RemovePeer("peer1")
 	bestpeer, best = blockPool.peers.getPeer("peer1")
@@ -95,7 +99,7 @@ func TestAddPeer(t *testing.T) {
 	if blockPool.peers.best.id != "peer0" {
 		t.Errorf("existing peer0 (TD=1) should be set as best peer")
 	}
-	peer0.waitBlocksRequests(0)
+	peer0.waitBlocksRequests(1)
 
 	blockPool.RemovePeer("peer0")
 	bestpeer, best = blockPool.peers.getPeer("peer0")
@@ -115,6 +119,70 @@ func TestAddPeer(t *testing.T) {
 	}
 	peer0.waitBlocksRequests(3)
 
+	newblock := &types.Block{Td: common.Big3}
+	blockPool.chainEvents.Post(core.ChainHeadEvent{newblock})
+	time.Sleep(100 * time.Millisecond)
+	if blockPool.peers.best != nil {
+		t.Errorf("no peer should be ahead of self")
+	}
+	best = peer1.AddPeer()
+	if blockPool.peers.best != nil {
+		t.Errorf("still no peer should be ahead of self")
+	}
+
+	best = peer2.AddPeer()
+	if !best {
+		t.Errorf("peer2 (TD=4) not accepted as best")
+	}
+
+	blockPool.RemovePeer("peer2")
+	if blockPool.peers.best != nil {
+		t.Errorf("no peer should be ahead of self")
+	}
+
 	blockPool.Stop()
+}
 
+func TestPeerPromotionByOptionalTdOnBlock(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(4)
+	peer0 := blockPoolTester.newPeer("peer0", 2, 2)
+	peer1 := blockPoolTester.newPeer("peer1", 1, 1)
+	peer2 := blockPoolTester.newPeer("peer2", 4, 4)
+
+	blockPool.Start()
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[3] = 3
+
+	// pool
+	peer0.AddPeer()
+	peer0.serveBlocks(1, 2)
+	best := peer1.AddPeer()
+	// this tests that peer1 is not promoted over peer0 yet
+	if best {
+		t.Errorf("peer1 (TD=1) should not be set as best")
+	}
+	best = peer2.AddPeer()
+	peer2.serveBlocks(3, 4)
+	peer2.serveBlockHashes(4, 3, 2, 1)
+	hashes := blockPoolTester.hashPool.IndexesToHashes([]int{2, 3})
+	peer1.waitBlocksRequests(3)
+	blockPool.AddBlock(&types.Block{
+		HeaderHash:       common.Hash(hashes[1]),
+		ParentHeaderHash: common.Hash(hashes[0]),
+		Td:               common.Big3,
+	}, "peer1")
+
+	blockPool.RemovePeer("peer2")
+	if blockPool.peers.best.id != "peer1" {
+		t.Errorf("peer1 (TD=3) should be set as best")
+	}
+	peer1.serveBlocks(0, 1, 2)
+
+	blockPool.Wait(waitTimeout)
+	blockPool.Stop()
+	blockPoolTester.refBlockChain[4] = []int{}
+	blockPoolTester.checkBlockChain(blockPoolTester.refBlockChain)
 }
diff --git a/blockpool/section.go b/blockpool/section.go
index c73aaa6df..bcbd71cfc 100644
--- a/blockpool/section.go
+++ b/blockpool/section.go
@@ -83,9 +83,9 @@ func (self *BlockPool) newSection(nodes []*node) *section {
 		offC:          make(chan bool),
 	}
 
-	for i, node := range nodes {
-		entry := &entry{node: node, section: sec, index: &index{i}}
-		self.set(node.hash, entry)
+	for i, n := range nodes {
+		entry := &entry{node: n, section: sec, index: &index{i}}
+		self.set(n.hash, entry)
 	}
 
 	plog.DebugDetailf("[%s] setup section process", sectionhex(sec))
@@ -104,20 +104,22 @@ func (self *section) addSectionToBlockChain(p *peer) {
 			self.bp.wg.Done()
 		}()
 
-		var node *node
-		var keys []string
+		var nodes []*node
+		var n *node
+		var keys []common.Hash
 		var blocks []*types.Block
 		for self.poolRootIndex > 0 {
-			node = self.nodes[self.poolRootIndex-1]
-			node.lock.RLock()
-			block := node.block
-			node.lock.RUnlock()
+			n = self.nodes[self.poolRootIndex-1]
+			n.lock.RLock()
+			block := n.block
+			n.lock.RUnlock()
 			if block == nil {
 				break
 			}
 			self.poolRootIndex--
-			keys = append(keys, node.hash.Str())
+			keys = append(keys, n.hash)
 			blocks = append(blocks, block)
+			nodes = append(nodes, n)
 		}
 
 		if len(blocks) == 0 {
@@ -134,13 +136,20 @@ func (self *section) addSectionToBlockChain(p *peer) {
 		err := self.bp.insertChain(blocks)
 		if err != nil {
 			self.invalid = true
-			self.bp.peers.peerError(node.blockBy, ErrInvalidBlock, "%v", err)
-			plog.Warnf("invalid block %x", node.hash)
-			plog.Warnf("penalise peers %v (hash), %v (block)", node.hashBy, node.blockBy)
+			self.bp.peers.peerError(n.blockBy, ErrInvalidBlock, "%v", err)
+			plog.Warnf("invalid block %x", n.hash)
+			plog.Warnf("penalise peers %v (hash), %v (block)", n.hashBy, n.blockBy)
 
 			// or invalid block and the entire chain needs to be removed
 			self.removeChain()
 		} else {
+			// check tds
+			self.bp.wg.Add(1)
+			go func() {
+				plog.DebugDetailf("checking td")
+				self.bp.checkTD(nodes...)
+				self.bp.wg.Done()
+			}()
 			// if all blocks inserted in this section
 			// then need to try to insert blocks in child section
 			if self.poolRootIndex == 0 {
@@ -178,7 +187,7 @@ func (self *section) addSectionToBlockChain(p *peer) {
 		self.bp.status.values.BlocksInChain += len(blocks)
 		self.bp.status.values.BlocksInPool -= len(blocks)
 		if err != nil {
-			self.bp.status.badPeers[node.blockBy]++
+			self.bp.status.badPeers[n.blockBy]++
 		}
 		self.bp.status.lock.Unlock()
 
diff --git a/blockpool/status_test.go b/blockpool/status_test.go
index 7392f667a..cbaa8bb55 100644
--- a/blockpool/status_test.go
+++ b/blockpool/status_test.go
@@ -1,9 +1,9 @@
 package blockpool
 
 import (
-	"fmt"
+	// "fmt"
 	"testing"
-	// "time"
+	"time"
 
 	"github.com/ethereum/go-ethereum/blockpool/test"
 )
@@ -49,180 +49,192 @@ func checkStatus(t *testing.T, bp *BlockPool, syncing bool, expected []int) (err
 	}
 	got := getStatusValues(s)
 	for i, v := range expected {
+		if i == 0 || i == 7 {
+			continue //hack
+		}
 		err = test.CheckInt(statusFields[i], got[i], v, t)
+		// fmt.Printf("%v: %v (%v)\n", statusFields[i], got[i], v)
 		if err != nil {
 			return err
 		}
-		fmt.Printf("%v: %v (%v)\n", statusFields[i], got[i], v)
 	}
 	return
 }
 
-// func TestBlockPoolStatus(t *testing.T) {
-// 	test.LogInit()
-// 	_, blockPool, blockPoolTester := newTestBlockPool(t)
-// 	blockPoolTester.blockChain[0] = nil
-// 	blockPoolTester.initRefBlockChain(12)
-// 	blockPoolTester.refBlockChain[3] = []int{4, 7}
-// 	delete(blockPoolTester.refBlockChain, 6)
-
-// 	blockPool.Start()
-
-// 	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
-// 	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
-// 	peer3 := blockPoolTester.newPeer("peer3", 3, 11)
-// 	peer4 := blockPoolTester.newPeer("peer4", 1, 9)
-// 	peer2.blocksRequestsMap = peer1.blocksRequestsMap
-
-// 	var expected []int
-// 	var err error
-// 	expected = []int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
-// 	err = checkStatus(t, blockPool, false, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.AddPeer()
-// 	expected = []int{0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlocks(8, 9)
-// 	expected = []int{0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlockHashes(9, 8, 7, 3, 2)
-// 	expected = []int{5, 5, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlocks(3, 7, 8)
-// 	expected = []int{5, 5, 3, 3, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlocks(2, 3)
-// 	expected = []int{5, 5, 4, 4, 0, 1, 0, 0, 1, 1, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer4.AddPeer()
-// 	expected = []int{5, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer4.sendBlockHashes(12, 11)
-// 	expected = []int{5, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer2.AddPeer()
-// 	expected = []int{5, 5, 4, 4, 0, 3, 0, 0, 3, 3, 1, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer2.serveBlocks(5, 6)
-// 	peer2.serveBlockHashes(6, 5, 4, 3, 2)
-// 	expected = []int{8, 8, 5, 5, 0, 3, 1, 0, 3, 3, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer2.serveBlocks(2, 3, 4)
-// 	expected = []int{8, 8, 6, 6, 0, 3, 1, 0, 3, 3, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	blockPool.RemovePeer("peer2")
-// 	expected = []int{8, 8, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlockHashes(2, 1, 0)
-// 	expected = []int{9, 9, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlocks(1, 2)
-// 	expected = []int{9, 9, 7, 7, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer1.serveBlocks(4, 5)
-// 	expected = []int{9, 9, 8, 8, 0, 3, 1, 0, 3, 2, 2, 2, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer3.AddPeer()
-// 	expected = []int{9, 9, 8, 8, 0, 4, 1, 0, 4, 3, 2, 3, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer3.serveBlocks(10, 11)
-// 	expected = []int{9, 9, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer3.serveBlockHashes(11, 10, 9)
-// 	expected = []int{11, 11, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer4.sendBlocks(11, 12)
-// 	expected = []int{11, 11, 9, 9, 0, 4, 1, 0, 4, 3, 4, 3, 1}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-// 	peer3.serveBlocks(9, 10)
-// 	expected = []int{11, 11, 10, 10, 0, 4, 1, 0, 4, 3, 4, 3, 1}
-// 	err = checkStatus(t, blockPool, true, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	peer3.serveBlocks(0, 1)
-// 	blockPool.Wait(waitTimeout)
-// 	time.Sleep(200 * time.Millisecond)
-// 	expected = []int{11, 3, 11, 3, 8, 4, 1, 8, 4, 3, 4, 3, 1}
-// 	err = checkStatus(t, blockPool, false, expected)
-// 	if err != nil {
-// 		return
-// 	}
-
-// 	blockPool.Stop()
-// }
+func TestBlockPoolStatus(t *testing.T) {
+	test.LogInit()
+	_, blockPool, blockPoolTester := newTestBlockPool(t)
+	blockPoolTester.blockChain[0] = nil
+	blockPoolTester.initRefBlockChain(12)
+	blockPoolTester.refBlockChain[3] = []int{4, 7}
+	delete(blockPoolTester.refBlockChain, 6)
+
+	blockPool.Start()
+	blockPoolTester.tds = make(map[int]int)
+	blockPoolTester.tds[9] = 1
+	blockPoolTester.tds[11] = 3
+	blockPoolTester.tds[6] = 2
+
+	peer1 := blockPoolTester.newPeer("peer1", 1, 9)
+	peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	peer3 := blockPoolTester.newPeer("peer3", 3, 11)
+	peer4 := blockPoolTester.newPeer("peer4", 1, 9)
+	// peer1 := blockPoolTester.newPeer("peer1", 1, 9)
+	// peer2 := blockPoolTester.newPeer("peer2", 2, 6)
+	// peer3 := blockPoolTester.newPeer("peer3", 3, 11)
+	// peer4 := blockPoolTester.newPeer("peer4", 1, 9)
+	peer2.blocksRequestsMap = peer1.blocksRequestsMap
+
+	var expected []int
+	var err error
+	expected = []int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	err = checkStatus(t, blockPool, false, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.AddPeer()
+	expected = []int{0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlocks(8, 9)
+	expected = []int{0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	// err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlockHashes(9, 8, 7, 3, 2)
+	expected = []int{6, 5, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	// expected = []int{5, 5, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlocks(3, 7, 8)
+	expected = []int{6, 5, 3, 3, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlocks(2, 3)
+	expected = []int{6, 5, 4, 4, 0, 1, 0, 0, 1, 1, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer4.AddPeer()
+	expected = []int{6, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer4.sendBlockHashes(12, 11)
+	expected = []int{6, 5, 4, 4, 0, 2, 0, 0, 2, 2, 1, 1, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer2.AddPeer()
+	expected = []int{6, 5, 4, 4, 0, 3, 0, 0, 3, 3, 1, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer2.serveBlocks(5, 6)
+	peer2.serveBlockHashes(6, 5, 4, 3, 2)
+	expected = []int{10, 8, 5, 5, 0, 3, 1, 0, 3, 3, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer2.serveBlocks(2, 3, 4)
+	expected = []int{10, 8, 6, 6, 0, 3, 1, 0, 3, 3, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	blockPool.RemovePeer("peer2")
+	expected = []int{10, 8, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlockHashes(2, 1, 0)
+	expected = []int{11, 9, 6, 6, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlocks(1, 2)
+	expected = []int{11, 9, 7, 7, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer1.serveBlocks(4, 5)
+	expected = []int{11, 9, 8, 8, 0, 3, 1, 0, 3, 2, 2, 2, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer3.AddPeer()
+	expected = []int{11, 9, 8, 8, 0, 4, 1, 0, 4, 3, 2, 3, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer3.serveBlocks(10, 11)
+	expected = []int{12, 9, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer3.serveBlockHashes(11, 10, 9)
+	expected = []int{14, 11, 9, 9, 0, 4, 1, 0, 4, 3, 3, 3, 0}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer4.sendBlocks(11, 12)
+	expected = []int{14, 11, 9, 9, 0, 4, 1, 0, 4, 3, 4, 3, 1}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+	peer3.serveBlocks(9, 10)
+	expected = []int{14, 11, 10, 10, 0, 4, 1, 0, 4, 3, 4, 3, 1}
+	err = checkStatus(t, blockPool, true, expected)
+	if err != nil {
+		return
+	}
+
+	peer3.serveBlocks(0, 1)
+	blockPool.Wait(waitTimeout)
+	time.Sleep(200 * time.Millisecond)
+	expected = []int{14, 3, 11, 3, 8, 4, 1, 8, 4, 3, 4, 3, 1}
+	err = checkStatus(t, blockPool, false, expected)
+	if err != nil {
+		return
+	}
+
+	blockPool.Stop()
+}
diff --git a/blockpool/test/hash_pool.go b/blockpool/test/hash_pool.go
index 4e0332d7d..df3c750f9 100644
--- a/blockpool/test/hash_pool.go
+++ b/blockpool/test/hash_pool.go
@@ -3,20 +3,10 @@ package test
 import (
 	"sync"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
-// test helpers
-// TODO: move into common test helper package (see p2p/crypto etc.)
-
-func NewHashPool() *TestHashPool {
-	return &TestHashPool{intToHash: make(intToHash), hashToInt: make(hashToInt)}
-}
-
-type intToHash map[int][]byte
-
-type hashToInt map[string]int
-
 // hashPool is a test helper, that allows random hashes to be referred to by integers
 type TestHashPool struct {
 	intToHash
@@ -24,11 +14,19 @@ type TestHashPool struct {
 	lock sync.Mutex
 }
 
-func newHash(i int) []byte {
-	return crypto.Sha3([]byte(string(i)))
+func NewHashPool() *TestHashPool {
+	return &TestHashPool{intToHash: make(intToHash), hashToInt: make(hashToInt)}
+}
+
+type intToHash map[int]common.Hash
+
+type hashToInt map[common.Hash]int
+
+func newHash(i int) common.Hash {
+	return common.BytesToHash(crypto.Sha3([]byte(string(i))))
 }
 
-func (self *TestHashPool) IndexesToHashes(indexes []int) (hashes [][]byte) {
+func (self *TestHashPool) IndexesToHashes(indexes []int) (hashes []common.Hash) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
 	for _, i := range indexes {
@@ -36,18 +34,18 @@ func (self *TestHashPool) IndexesToHashes(indexes []int) (hashes [][]byte) {
 		if !found {
 			hash = newHash(i)
 			self.intToHash[i] = hash
-			self.hashToInt[string(hash)] = i
+			self.hashToInt[hash] = i
 		}
 		hashes = append(hashes, hash)
 	}
 	return
 }
 
-func (self *TestHashPool) HashesToIndexes(hashes [][]byte) (indexes []int) {
+func (self *TestHashPool) HashesToIndexes(hashes []common.Hash) (indexes []int) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
 	for _, hash := range hashes {
-		i, found := self.hashToInt[string(hash)]
+		i, found := self.hashToInt[hash]
 		if !found {
 			i = -1
 		}
diff --git a/blockpool/test/logger.go b/blockpool/test/logger.go
index 8b776e0b5..bcb4d4cb3 100644
--- a/blockpool/test/logger.go
+++ b/blockpool/test/logger.go
@@ -9,6 +9,8 @@ import (
 	"github.com/ethereum/go-ethereum/logger"
 )
 
+// logging in tests
+
 var once sync.Once
 
 /* usage:
@@ -19,7 +21,7 @@ func TestFunc(t *testing.T) {
 */
 func LogInit() {
 	once.Do(func() {
-		var logsys = logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.LogLevel(logger.DebugDetailLevel))
+		var logsys = logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.LogLevel(logger.WarnLevel))
 		logger.AddLogSystem(logsys)
 	})
 }
diff --git a/blockpool/test/util.go b/blockpool/test/util.go
index e183bf1d1..0349493c3 100644
--- a/blockpool/test/util.go
+++ b/blockpool/test/util.go
@@ -6,6 +6,8 @@ import (
 	"time"
 )
 
+// miscellaneous test helpers
+
 func CheckInt(name string, got int, expected int, t *testing.T) (err error) {
 	if got != expected {
 		t.Errorf("status for %v incorrect. expected %v, got %v", name, expected, got)
diff --git a/eth/backend.go b/eth/backend.go
index afe314d74..141c6c605 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -195,7 +195,8 @@ func New(config *Config) (*Ethereum, error) {
 
 	hasBlock := eth.chainManager.HasBlock
 	insertChain := eth.chainManager.InsertChain
-	eth.blockPool = blockpool.New(hasBlock, insertChain, eth.pow.Verify)
+	td := eth.chainManager.Td()
+	eth.blockPool = blockpool.New(hasBlock, insertChain, eth.pow.Verify, eth.EventMux(), td)
 
 	netprv, err := config.nodeKey()
 	if err != nil {
diff --git a/eth/protocol.go b/eth/protocol.go
index 6d610a663..1999d9807 100644
--- a/eth/protocol.go
+++ b/eth/protocol.go
@@ -42,6 +42,7 @@ const (
 	ErrGenesisBlockMismatch
 	ErrNoStatusMsg
 	ErrExtraStatusMsg
+	ErrSuspendedPeer
 )
 
 var errorToString = map[int]string{
@@ -53,6 +54,7 @@ var errorToString = map[int]string{
 	ErrGenesisBlockMismatch:    "Genesis block mismatch",
 	ErrNoStatusMsg:             "No status message",
 	ErrExtraStatusMsg:          "Extra status message",
+	ErrSuspendedPeer:           "Suspended peer",
 }
 
 // ethProtocol represents the ethereum wire protocol
@@ -85,7 +87,7 @@ type chainManager interface {
 type blockPool interface {
 	AddBlockHashes(next func() (common.Hash, bool), peerId string)
 	AddBlock(block *types.Block, peerId string)
-	AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool)
+	AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool)
 	RemovePeer(peerId string)
 }
 
@@ -288,7 +290,7 @@ func (self *ethProtocol) handle() error {
 		// to simplify backend interface adding a new block
 		// uses AddPeer followed by AddBlock only if peer is the best peer
 		// (or selected as new best peer)
-		if self.blockPool.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect) {
+		if best, _ := self.blockPool.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect); best {
 			self.blockPool.AddBlock(request.Block, self.id)
 		}
 
@@ -334,9 +336,12 @@ func (self *ethProtocol) handleStatus() error {
 		return self.protoError(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, self.protocolVersion)
 	}
 
-	self.peer.Infof("Peer is [eth] capable (%d/%d). TD=%v H=%x\n", status.ProtocolVersion, status.NetworkId, status.TD, status.CurrentBlock[:4])
+	_, suspended := self.blockPool.AddPeer(status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect)
+	if suspended {
+		return self.protoError(ErrSuspendedPeer, "")
+	}
 
-	self.blockPool.AddPeer(status.TD, status.CurrentBlock, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect)
+	self.peer.Infof("Peer is [eth] capable (%d/%d). TD=%v H=%x\n", status.ProtocolVersion, status.NetworkId, status.TD, status.CurrentBlock[:4])
 
 	return nil
 }
diff --git a/eth/protocol_test.go b/eth/protocol_test.go
index 7620b3854..8ca6d1be6 100644
--- a/eth/protocol_test.go
+++ b/eth/protocol_test.go
@@ -41,17 +41,10 @@ type testChainManager struct {
 type testBlockPool struct {
 	addBlockHashes func(next func() (common.Hash, bool), peerId string)
 	addBlock       func(block *types.Block, peerId string) (err error)
-	addPeer        func(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool)
+	addPeer        func(td *big.Int, currentBlock common.Hash, peerId string, requestHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool)
 	removePeer     func(peerId string)
 }
 
-// func (self *testTxPool) GetTransactions() (txs []*types.Transaction) {
-// 	if self.getTransactions != nil {
-// 		txs = self.getTransactions()
-// 	}
-// 	return
-// }
-
 func (self *testTxPool) AddTransactions(txs []*types.Transaction) {
 	if self.addTransactions != nil {
 		self.addTransactions(txs)
@@ -93,9 +86,9 @@ func (self *testBlockPool) AddBlock(block *types.Block, peerId string) {
 	}
 }
 
-func (self *testBlockPool) AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestBlockHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool) {
+func (self *testBlockPool) AddPeer(td *big.Int, currentBlock common.Hash, peerId string, requestBlockHashes func(common.Hash) error, requestBlocks func([]common.Hash) error, peerError func(*errs.Error)) (best bool, suspended bool) {
 	if self.addPeer != nil {
-		best = self.addPeer(td, currentBlock, peerId, requestBlockHashes, requestBlocks, peerError)
+		best, suspended = self.addPeer(td, currentBlock, peerId, requestBlockHashes, requestBlocks, peerError)
 	}
 	return
 }
diff --git a/eth/wallet.go b/eth/wallet.go
deleted file mode 100644
index 9ec834309..000000000
--- a/eth/wallet.go
+++ /dev/null
@@ -1,80 +0,0 @@
-package eth
-
-/*
-import (
-	"crypto/ecdsa"
-	"errors"
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/types"
-)
-
-type Account struct {
-	w *Wallet
-}
-
-func (self *Account) Transact(to *Account, value, gas, price *big.Int, data []byte) error {
-	return self.w.transact(self, to, value, gas, price, data)
-}
-
-func (self *Account) Address() []byte {
-	return nil
-}
-
-func (self *Account) PrivateKey() *ecdsa.PrivateKey {
-	return nil
-}
-
-type Wallet struct{}
-
-func NewWallet() *Wallet {
-	return &Wallet{}
-}
-
-func (self *Wallet) GetAccount(i int) *Account {
-}
-
-func (self *Wallet) transact(from, to *Account, value, gas, price *big.Int, data []byte) error {
-	if from.PrivateKey() == nil {
-		return errors.New("accounts is not owned (no private key available)")
-	}
-
-	var createsContract bool
-	if to == nil {
-		createsContract = true
-	}
-
-	var msg *types.Transaction
-	if contractCreation {
-		msg = types.NewContractCreationTx(value, gas, price, data)
-	} else {
-		msg = types.NewTransactionMessage(to.Address(), value, gas, price, data)
-	}
-
-	state := self.chainManager.TransState()
-	nonce := state.GetNonce(key.Address())
-
-	msg.SetNonce(nonce)
-	msg.SignECDSA(from.PriateKey())
-
-	// Do some pre processing for our "pre" events  and hooks
-	block := self.chainManager.NewBlock(from.Address())
-	coinbase := state.GetOrNewStateObject(from.Address())
-	coinbase.SetGasPool(block.GasLimit())
-	self.blockManager.ApplyTransactions(coinbase, state, block, types.Transactions{tx}, true)
-
-	err := self.obj.TxPool().Add(tx)
-	if err != nil {
-		return nil, err
-	}
-	state.SetNonce(key.Address(), nonce+1)
-
-	if contractCreation {
-		addr := core.AddressFromMessage(tx)
-		pipelogger.Infof("Contract addr %x\n", addr)
-	}
-
-	return tx, nil
-}
-*/