diff --git a/swarm/network/simulation/node.go b/swarm/network/simulation/node.go
index 46c2bb866..f66b0afd0 100644
--- a/swarm/network/simulation/node.go
+++ b/swarm/network/simulation/node.go
@@ -234,9 +234,9 @@ func (s *Simulation) UploadSnapshot(ctx context.Context, snapshotFile string, op
 	if err != nil {
 		return err
 	}
-	defer f.Close()
 
 	jsonbyte, err := ioutil.ReadAll(f)
+	f.Close()
 	if err != nil {
 		return err
 	}
diff --git a/swarm/pss/prox_test.go b/swarm/pss/prox_test.go
index bc32e612d..908a0d330 100644
--- a/swarm/pss/prox_test.go
+++ b/swarm/pss/prox_test.go
@@ -4,10 +4,7 @@ import (
 	"context"
 	"crypto/ecdsa"
 	"encoding/binary"
-	"errors"
 	"fmt"
-	"strconv"
-	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -39,24 +36,20 @@ type handlerNotification struct {
 }
 
 type testData struct {
-	mu               sync.Mutex
-	sim              *simulation.Simulation
-	handlerDone      bool // set to true on termination of the simulation run
-	requiredMessages int
-	allowedMessages  int
-	messageCount     int
-	kademlias        map[enode.ID]*network.Kademlia
-	nodeAddrs        map[enode.ID][]byte      // make predictable overlay addresses from the generated random enode ids
-	recipients       map[int][]enode.ID       // for logging output only
-	allowed          map[int][]enode.ID       // allowed recipients
-	expectedMsgs     map[enode.ID][]uint64    // message serials we expect respective nodes to receive
-	allowedMsgs      map[enode.ID][]uint64    // message serials we expect respective nodes to receive
-	senders          map[int]enode.ID         // originating nodes of the messages (intention is to choose as far as possible from the receiving neighborhood)
-	handlerC         chan handlerNotification // passes message from pss message handler to simulation driver
-	doneC            chan struct{}            // terminates the handler channel listener
-	errC             chan error               // error to pass to main sim thread
-	msgC             chan handlerNotification // message receipt notification to main sim thread
-	msgs             [][]byte                 // recipient addresses of messages
+	sim                *simulation.Simulation
+	kademlias          map[enode.ID]*network.Kademlia
+	nodeAddresses      map[enode.ID][]byte // make predictable overlay addresses from the generated random enode ids
+	senders            map[int]enode.ID    // originating nodes of the messages (intention is to choose as far as possible from the receiving neighborhood)
+	recipientAddresses [][]byte
+
+	requiredMsgCount int
+	requiredMsgs     map[enode.ID][]uint64 // message serials we expect respective nodes to receive
+	allowedMsgs      map[enode.ID][]uint64 // message serials we expect respective nodes to receive
+
+	notifications []handlerNotification // notification queue
+	totalMsgCount int
+	handlerDone   bool // set to true on termination of the simulation run
+	mu            sync.Mutex
 }
 
 var (
@@ -64,67 +57,60 @@ var (
 	topic = BytesToTopic([]byte{0xf3, 0x9e, 0x06, 0x82})
 )
 
-func (d *testData) getMsgCount() int {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	return d.messageCount
+func (td *testData) pushNotification(val handlerNotification) {
+	td.mu.Lock()
+	td.notifications = append(td.notifications, val)
+	td.mu.Unlock()
 }
 
-func (d *testData) incrementMsgCount() int {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	d.messageCount++
-	return d.messageCount
-}
-
-func (d *testData) isDone() bool {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	return d.handlerDone
-}
-
-func (d *testData) setDone() {
-	d.mu.Lock()
-	defer d.mu.Unlock()
-	d.handlerDone = true
-}
-
-func getCmdParams(t *testing.T) (int, int, time.Duration) {
-	args := strings.Split(t.Name(), "/")
-	msgCount, err := strconv.ParseInt(args[2], 10, 16)
-	if err != nil {
-		t.Fatal(err)
+func (td *testData) popNotification() (first handlerNotification, exist bool) {
+	td.mu.Lock()
+	if len(td.notifications) > 0 {
+		exist = true
+		first = td.notifications[0]
+		td.notifications = td.notifications[1:]
 	}
-	nodeCount, err := strconv.ParseInt(args[1], 10, 16)
-	if err != nil {
-		t.Fatal(err)
-	}
-	timeoutStr := fmt.Sprintf("%ss", args[3])
-	timeoutDur, err := time.ParseDuration(timeoutStr)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return int(msgCount), int(nodeCount), timeoutDur
+	td.mu.Unlock()
+	return first, exist
+}
+
+func (td *testData) getMsgCount() int {
+	td.mu.Lock()
+	defer td.mu.Unlock()
+	return td.totalMsgCount
+}
+
+func (td *testData) incrementMsgCount() int {
+	td.mu.Lock()
+	defer td.mu.Unlock()
+	td.totalMsgCount++
+	return td.totalMsgCount
+}
+
+func (td *testData) isDone() bool {
+	td.mu.Lock()
+	defer td.mu.Unlock()
+	return td.handlerDone
+}
+
+func (td *testData) setDone() {
+	td.mu.Lock()
+	defer td.mu.Unlock()
+	td.handlerDone = true
 }
 
 func newTestData() *testData {
 	return &testData{
-		kademlias:    make(map[enode.ID]*network.Kademlia),
-		nodeAddrs:    make(map[enode.ID][]byte),
-		recipients:   make(map[int][]enode.ID),
-		allowed:      make(map[int][]enode.ID),
-		expectedMsgs: make(map[enode.ID][]uint64),
-		allowedMsgs:  make(map[enode.ID][]uint64),
-		senders:      make(map[int]enode.ID),
-		handlerC:     make(chan handlerNotification),
-		doneC:        make(chan struct{}),
-		errC:         make(chan error),
-		msgC:         make(chan handlerNotification),
+		kademlias:     make(map[enode.ID]*network.Kademlia),
+		nodeAddresses: make(map[enode.ID][]byte),
+		requiredMsgs:  make(map[enode.ID][]uint64),
+		allowedMsgs:   make(map[enode.ID][]uint64),
+		senders:       make(map[int]enode.ID),
 	}
 }
 
-func (d *testData) getKademlia(nodeId *enode.ID) (*network.Kademlia, error) {
-	kadif, ok := d.sim.NodeItem(*nodeId, simulation.BucketKeyKademlia)
+func (td *testData) getKademlia(nodeId *enode.ID) (*network.Kademlia, error) {
+	kadif, ok := td.sim.NodeItem(*nodeId, simulation.BucketKeyKademlia)
 	if !ok {
 		return nil, fmt.Errorf("no kademlia entry for %v", nodeId)
 	}
@@ -135,29 +121,29 @@ func (d *testData) getKademlia(nodeId *enode.ID) (*network.Kademlia, error) {
 	return kad, nil
 }
 
-func (d *testData) init(msgCount int) error {
+func (td *testData) init(msgCount int) error {
 	log.Debug("TestProxNetwork start")
 
-	for _, nodeId := range d.sim.NodeIDs() {
-		kad, err := d.getKademlia(&nodeId)
+	for _, nodeId := range td.sim.NodeIDs() {
+		kad, err := td.getKademlia(&nodeId)
 		if err != nil {
 			return err
 		}
-		d.nodeAddrs[nodeId] = kad.BaseAddr()
+		td.nodeAddresses[nodeId] = kad.BaseAddr()
 	}
 
 	for i := 0; i < int(msgCount); i++ {
 		msgAddr := pot.RandomAddress() // we choose message addresses randomly
-		d.msgs = append(d.msgs, msgAddr.Bytes())
+		td.recipientAddresses = append(td.recipientAddresses, msgAddr.Bytes())
 		smallestPo := 256
 		var targets []enode.ID
 		var closestPO int
 
 		// loop through all nodes and find the required and allowed recipients of each message
 		// (for more information, please see the comment to the main test function)
-		for _, nod := range d.sim.Net.GetNodes() {
-			po, _ := pof(d.msgs[i], d.nodeAddrs[nod.ID()], 0)
-			depth := d.kademlias[nod.ID()].NeighbourhoodDepth()
+		for _, nod := range td.sim.Net.GetNodes() {
+			po, _ := pof(td.recipientAddresses[i], td.nodeAddresses[nod.ID()], 0)
+			depth := td.kademlias[nod.ID()].NeighbourhoodDepth()
 
 			// only nodes with closest IDs (wrt the msg address) will be required recipients
 			if po > closestPO {
@@ -169,28 +155,25 @@ func (d *testData) init(msgCount int) error {
 			}
 
 			if po >= depth {
-				d.allowedMessages++
-				d.allowed[i] = append(d.allowed[i], nod.ID())
-				d.allowedMsgs[nod.ID()] = append(d.allowedMsgs[nod.ID()], uint64(i))
+				td.allowedMsgs[nod.ID()] = append(td.allowedMsgs[nod.ID()], uint64(i))
 			}
 
 			// a node with the smallest PO (wrt msg) will be the sender,
 			// in order to increase the distance the msg must travel
 			if po < smallestPo {
 				smallestPo = po
-				d.senders[i] = nod.ID()
+				td.senders[i] = nod.ID()
 			}
 		}
 
-		d.requiredMessages += len(targets)
+		td.requiredMsgCount += len(targets)
 		for _, id := range targets {
-			d.recipients[i] = append(d.recipients[i], id)
-			d.expectedMsgs[id] = append(d.expectedMsgs[id], uint64(i))
+			td.requiredMsgs[id] = append(td.requiredMsgs[id], uint64(i))
 		}
 
-		log.Debug("nn for msg", "targets", len(d.recipients[i]), "msgidx", i, "msg", common.Bytes2Hex(msgAddr[:8]), "sender", d.senders[i], "senderpo", smallestPo)
+		log.Debug("nn for msg", "targets", len(targets), "msgidx", i, "msg", common.Bytes2Hex(msgAddr[:8]), "sender", td.senders[i], "senderpo", smallestPo)
 	}
-	log.Debug("msgs to receive", "count", d.requiredMessages)
+	log.Debug("recipientAddresses to receive", "count", td.requiredMsgCount)
 	return nil
 }
 
@@ -213,144 +196,161 @@ func (d *testData) init(msgCount int) error {
 // nodes Y and Z will be considered required recipients of the msg,
 // whereas nodes X, Y and Z will be allowed recipients.
 func TestProxNetwork(t *testing.T) {
-	t.Run("16/16/15", testProxNetwork)
+	t.Run("16_nodes,_16_messages,_16_seconds", func(t *testing.T) {
+		testProxNetwork(t, 16, 16, 16*time.Second)
+	})
 }
 
-// params in run name: nodes/msgs
 func TestProxNetworkLong(t *testing.T) {
 	if !*longrunning {
 		t.Skip("run with --longrunning flag to run extensive network tests")
 	}
-	t.Run("8/100/30", testProxNetwork)
-	t.Run("16/100/30", testProxNetwork)
-	t.Run("32/100/60", testProxNetwork)
-	t.Run("64/100/60", testProxNetwork)
-	t.Run("128/100/120", testProxNetwork)
+	t.Run("8_nodes,_100_messages,_30_seconds", func(t *testing.T) {
+		testProxNetwork(t, 8, 100, 30*time.Second)
+	})
+	t.Run("16_nodes,_100_messages,_30_seconds", func(t *testing.T) {
+		testProxNetwork(t, 16, 100, 30*time.Second)
+	})
+	t.Run("32_nodes,_100_messages,_60_seconds", func(t *testing.T) {
+		testProxNetwork(t, 32, 100, 1*time.Minute)
+	})
+	t.Run("64_nodes,_100_messages,_60_seconds", func(t *testing.T) {
+		testProxNetwork(t, 64, 100, 1*time.Minute)
+	})
+	t.Run("128_nodes,_100_messages,_120_seconds", func(t *testing.T) {
+		testProxNetwork(t, 128, 100, 2*time.Minute)
+	})
 }
 
-func testProxNetwork(t *testing.T) {
-	tstdata := newTestData()
-	msgCount, nodeCount, timeout := getCmdParams(t)
+func testProxNetwork(t *testing.T, nodeCount int, msgCount int, timeout time.Duration) {
+	td := newTestData()
 	handlerContextFuncs := make(map[Topic]handlerContextFunc)
 	handlerContextFuncs[topic] = nodeMsgHandler
-	services := newProxServices(tstdata, true, handlerContextFuncs, tstdata.kademlias)
-	tstdata.sim = simulation.New(services)
-	defer tstdata.sim.Close()
+	services := newProxServices(td, true, handlerContextFuncs, td.kademlias)
+	td.sim = simulation.New(services)
+	defer td.sim.Close()
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 	filename := fmt.Sprintf("testdata/snapshot_%d.json", nodeCount)
-	err := tstdata.sim.UploadSnapshot(ctx, filename)
+	err := td.sim.UploadSnapshot(ctx, filename)
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = tstdata.init(msgCount) // initialize the test data
+	err = td.init(msgCount) // initialize the test data
 	if err != nil {
 		t.Fatal(err)
 	}
 	wrapper := func(c context.Context, _ *simulation.Simulation) error {
-		return testRoutine(tstdata, c)
+		return testRoutine(td, c)
 	}
-	result := tstdata.sim.Run(ctx, wrapper) // call the main test function
+	result := td.sim.Run(ctx, wrapper) // call the main test function
 	if result.Error != nil {
-		// context deadline exceeded
-		// however, it might just mean that not all possible messages are received
-		// now we must check if all required messages are received
-		cnt := tstdata.getMsgCount()
-		log.Debug("TestProxNetwork finished", "rcv", cnt)
-		if cnt < tstdata.requiredMessages {
+		timedOut := result.Error == context.DeadlineExceeded
+		if !timedOut || td.getMsgCount() < td.requiredMsgCount {
 			t.Fatal(result.Error)
 		}
 	}
-	t.Logf("completed %d", result.Duration)
 }
 
-func (tstdata *testData) sendAllMsgs() {
-	for i, msg := range tstdata.msgs {
-		log.Debug("sending msg", "idx", i, "from", tstdata.senders[i])
-		nodeClient, err := tstdata.sim.Net.GetNode(tstdata.senders[i]).Client()
+func (td *testData) sendAllMsgs() error {
+	nodes := make(map[int]*rpc.Client)
+	for i := range td.recipientAddresses {
+		nodeClient, err := td.sim.Net.GetNode(td.senders[i]).Client()
 		if err != nil {
-			tstdata.errC <- err
+			return err
 		}
+		nodes[i] = nodeClient
+	}
+
+	for i, msg := range td.recipientAddresses {
+		log.Debug("sending msg", "idx", i, "from", td.senders[i])
+		nodeClient := nodes[i]
 		var uvarByte [8]byte
 		binary.PutUvarint(uvarByte[:], uint64(i))
 		nodeClient.Call(nil, "pss_sendRaw", hexutil.Encode(msg), hexutil.Encode(topic[:]), hexutil.Encode(uvarByte[:]))
 	}
-	log.Debug("all messages sent")
+	return nil
+}
+
+func isMoreTimeLeft(ctx context.Context) bool {
+	select {
+	case <-ctx.Done():
+		return false
+	default:
+		return true
+	}
 }
 
 // testRoutine is the main test function, called by Simulation.Run()
-func testRoutine(tstdata *testData, ctx context.Context) error {
-	go handlerChannelListener(tstdata, ctx)
-	go tstdata.sendAllMsgs()
-	received := 0
+func testRoutine(td *testData, ctx context.Context) error {
 
-	// collect incoming messages and terminate with corresponding status when message handler listener ends
-	for {
-		select {
-		case err := <-tstdata.errC:
-			return err
-		case hn := <-tstdata.msgC:
-			received++
-			log.Debug("msg received", "msgs_received", received, "total_expected", tstdata.requiredMessages, "id", hn.id, "serial", hn.serial)
-			if received == tstdata.allowedMessages {
-				close(tstdata.doneC)
-				return nil
-			}
+	hasMoreRound := func(err error, hadMessage bool) bool {
+		return err == nil && (hadMessage || isMoreTimeLeft(ctx))
+	}
+
+	if err := td.sendAllMsgs(); err != nil {
+		return err
+	}
+
+	var err error
+	received := 0
+	hadMessage := false
+
+	for oneMoreRound := true; oneMoreRound; oneMoreRound = hasMoreRound(err, hadMessage) {
+		message, hadMessage := td.popNotification()
+
+		if !isMoreTimeLeft(ctx) {
+			// Stop handlers from sending more messages.
+			// Note: only best effort, race is possible.
+			td.setDone()
 		}
+
+		if hadMessage {
+			if td.isAllowedMessage(message) {
+				received++
+				log.Debug("msg received", "msgs_received", received, "total_expected", td.requiredMsgCount, "id", message.id, "serial", message.serial)
+			} else {
+				err = fmt.Errorf("message %d received by wrong recipient %v", message.serial, message.id)
+			}
+		} else {
+			time.Sleep(32 * time.Millisecond)
+		}
+	}
+
+	if err != nil {
+		return err
+	}
+
+	if td.getMsgCount() < td.requiredMsgCount {
+		return ctx.Err()
 	}
 	return nil
 }
 
-func handlerChannelListener(tstdata *testData, ctx context.Context) {
-	for {
-		select {
-		case <-tstdata.doneC: // graceful exit
-			tstdata.setDone()
-			tstdata.errC <- nil
-			return
-
-		case <-ctx.Done(): // timeout or cancel
-			tstdata.setDone()
-			tstdata.errC <- ctx.Err()
-			return
-
-		// incoming message from pss message handler
-		case handlerNotification := <-tstdata.handlerC:
-			// check if recipient has already received all its messages and notify to fail the test if so
-			aMsgs := tstdata.allowedMsgs[handlerNotification.id]
-			if len(aMsgs) == 0 {
-				tstdata.setDone()
-				tstdata.errC <- fmt.Errorf("too many messages received by recipient %x", handlerNotification.id)
-				return
-			}
-
-			// check if message serial is in expected messages for this recipient and notify to fail the test if not
-			idx := -1
-			for i, msg := range aMsgs {
-				if handlerNotification.serial == msg {
-					idx = i
-					break
-				}
-			}
-			if idx == -1 {
-				tstdata.setDone()
-				tstdata.errC <- fmt.Errorf("message %d received by wrong recipient %v", handlerNotification.serial, handlerNotification.id)
-				return
-			}
-
-			// message is ok, so remove that message serial from the recipient expectation array and notify the main sim thread
-			aMsgs[idx] = aMsgs[len(aMsgs)-1]
-			aMsgs = aMsgs[:len(aMsgs)-1]
-			tstdata.msgC <- handlerNotification
+func (td *testData) isAllowedMessage(n handlerNotification) bool {
+	// check if message serial is in expected messages for this recipient
+	for _, s := range td.allowedMsgs[n.id] {
+		if n.serial == s {
+			return true
 		}
 	}
+	return false
 }
 
-func nodeMsgHandler(tstdata *testData, config *adapters.NodeConfig) *handler {
+func (td *testData) removeAllowedMessage(id enode.ID, index int) {
+	last := len(td.allowedMsgs[id]) - 1
+	td.allowedMsgs[id][index] = td.allowedMsgs[id][last]
+	td.allowedMsgs[id] = td.allowedMsgs[id][:last]
+}
+
+func nodeMsgHandler(td *testData, config *adapters.NodeConfig) *handler {
 	return &handler{
 		f: func(msg []byte, p *p2p.Peer, asymmetric bool, keyid string) error {
-			cnt := tstdata.incrementMsgCount()
-			log.Debug("nodeMsgHandler rcv", "cnt", cnt)
+			if td.isDone() {
+				return nil // terminate if simulation is over
+			}
+
+			td.incrementMsgCount()
 
 			// using simple serial in message body, makes it easy to keep track of who's getting what
 			serial, c := binary.Uvarint(msg)
@@ -358,15 +358,7 @@ func nodeMsgHandler(tstdata *testData, config *adapters.NodeConfig) *handler {
 				log.Crit(fmt.Sprintf("corrupt message received by %x (uvarint parse returned %d)", config.ID, c))
 			}
 
-			if tstdata.isDone() {
-				return errors.New("handlers aborted") // terminate if simulation is over
-			}
-
-			// pass message context to the listener in the simulation
-			tstdata.handlerC <- handlerNotification{
-				id:     config.ID,
-				serial: serial,
-			}
+			td.pushNotification(handlerNotification{id: config.ID, serial: serial})
 			return nil
 		},
 		caps: &handlerCaps{
@@ -378,7 +370,7 @@ func nodeMsgHandler(tstdata *testData, config *adapters.NodeConfig) *handler {
 
 // an adaptation of the same services setup as in pss_test.go
 // replaces pss_test.go when those tests are rewritten to the new swarm/network/simulation package
-func newProxServices(tstdata *testData, allowRaw bool, handlerContextFuncs map[Topic]handlerContextFunc, kademlias map[enode.ID]*network.Kademlia) map[string]simulation.ServiceFunc {
+func newProxServices(td *testData, allowRaw bool, handlerContextFuncs map[Topic]handlerContextFunc, kademlias map[enode.ID]*network.Kademlia) map[string]simulation.ServiceFunc {
 	stateStore := state.NewInmemoryStore()
 	kademlia := func(id enode.ID, bzzkey []byte) *network.Kademlia {
 		if k, ok := kademlias[id]; ok {
@@ -415,6 +407,9 @@ func newProxServices(tstdata *testData, allowRaw bool, handlerContextFuncs map[T
 				UnderlayAddr: addr.Under(),
 				HiveParams:   hp,
 			}
+			bzzKey := network.PrivateKeyToBzzKey(bzzPrivateKey)
+			pskad := kademlia(ctx.Config.ID, bzzKey)
+			b.Store(simulation.BucketKeyKademlia, pskad)
 			return network.NewBzz(config, kademlia(ctx.Config.ID, addr.OAddr), stateStore, nil, nil), nil, nil
 		},
 		"pss": func(ctx *adapters.ServiceContext, b *sync.Map) (node.Service, func(), error) {
@@ -434,6 +429,7 @@ func newProxServices(tstdata *testData, allowRaw bool, handlerContextFuncs map[T
 			}
 			bzzKey := network.PrivateKeyToBzzKey(bzzPrivateKey)
 			pskad := kademlia(ctx.Config.ID, bzzKey)
+			b.Store(simulation.BucketKeyKademlia, pskad)
 			ps, err := NewPss(pskad, pssp)
 			if err != nil {
 				return nil, nil, err
@@ -442,7 +438,7 @@ func newProxServices(tstdata *testData, allowRaw bool, handlerContextFuncs map[T
 			// register the handlers we've been passed
 			var deregisters []func()
 			for tpc, hndlrFunc := range handlerContextFuncs {
-				deregisters = append(deregisters, ps.Register(&tpc, hndlrFunc(tstdata, ctx.Config)))
+				deregisters = append(deregisters, ps.Register(&tpc, hndlrFunc(td, ctx.Config)))
 			}
 
 			// if handshake mode is set, add the controller
@@ -459,8 +455,6 @@ func newProxServices(tstdata *testData, allowRaw bool, handlerContextFuncs map[T
 				Public:    false,
 			})
 
-			b.Store(simulation.BucketKeyKademlia, pskad)
-
 			// return Pss and cleanups
 			return ps, func() {
 				// run the handler deregister functions in reverse order
diff --git a/swarm/pss/pss_test.go b/swarm/pss/pss_test.go
index ea7a591b1..9884ffbe9 100644
--- a/swarm/pss/pss_test.go
+++ b/swarm/pss/pss_test.go
@@ -1364,7 +1364,7 @@ func TestNetwork(t *testing.T) {
 }
 
 // params in run name:
-// nodes/msgs/addrbytes/adaptertype
+// nodes/recipientAddresses/addrbytes/adaptertype
 // if adaptertype is exec uses execadapter, simadapter otherwise
 func TestNetwork2000(t *testing.T) {
 	if !*longrunning {