diff --git a/swarm/network/request_test.go b/swarm/network/request_test.go
index 8e032c6a3b..758559cf5f 100644
--- a/swarm/network/request_test.go
+++ b/swarm/network/request_test.go
@@ -17,9 +17,29 @@
 package network
 
 import (
+	"context"
+	crand "crypto/rand"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"sync"
+	"sync/atomic"
 	"testing"
+	"time"
 
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/protocols"
+	"github.com/ethereum/go-ethereum/p2p/simulations"
+	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
 	p2ptest "github.com/ethereum/go-ethereum/p2p/testing"
+	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/ethereum/go-ethereum/swarm/storage"
 )
 
@@ -200,3 +220,364 @@ func TestStreamerUpstreamRetrieveRequestMsgExchange(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+// serviceName is used with the exec adapter so the exec'd binary knows which
+// service to execute
+const serviceName = "delivery"
+
+var services = adapters.Services{
+	serviceName: newService,
+}
+
+var (
+	adapter  = flag.String("adapter", "sim", "type of simulation: sim|socket|exec|docker")
+	loglevel = flag.Int("loglevel", 5, "verbosity of logs")
+)
+
+type roundRobinStore struct {
+	index  uint32
+	stores []storage.ChunkStore
+}
+
+func newRoundRobinStore(stores ...storage.ChunkStore) *roundRobinStore {
+	return &roundRobinStore{
+		stores: stores,
+	}
+}
+
+func (rrs *roundRobinStore) Get(key storage.Key) (*storage.Chunk, error) {
+	return nil, errors.New("get not well defined on round robin store")
+}
+
+func (rrs *roundRobinStore) Put(chunk *storage.Chunk) {
+	i := atomic.AddUint32(&rrs.index, 1)
+	idx := int(i) % len(rrs.stores)
+	log.Trace(fmt.Sprintf("put %v into localstore %v", chunk.Key, idx))
+	rrs.stores[idx].Put(chunk)
+}
+
+func (rrs *roundRobinStore) Close() {
+	for _, store := range rrs.stores {
+		store.Close()
+	}
+}
+
+func init() {
+	flag.Parse()
+	// register the Delivery service which will run as a devp2p
+	// protocol when using the exec adapter
+	adapters.RegisterServices(services)
+
+	log.Root().SetHandler(log.LvlFilterHandler(log.Lvl(*loglevel), log.StreamHandler(os.Stderr, log.TerminalFormat(false))))
+}
+
+func testSimulation(t *testing.T, simf func(adapters.NodeAdapter) (*simulations.StepResult, error)) {
+	var err error
+	var result *simulations.StepResult
+	startedAt := time.Now()
+
+	switch *adapter {
+	case "sim":
+		t.Logf("simadapter")
+		result, err = simf(adapters.NewSimAdapter(services))
+	case "socket":
+		result, err = simf(adapters.NewSocketAdapter(services))
+	case "exec":
+		baseDir, err0 := ioutil.TempDir("", "swarm-test")
+		if err0 != nil {
+			t.Fatal(err0)
+		}
+		defer os.RemoveAll(baseDir)
+		result, err = simf(adapters.NewExecAdapter(baseDir))
+	case "docker":
+		adapter, err0 := adapters.NewDockerAdapter()
+		if err0 != nil {
+			t.Fatal(err0)
+		}
+		result, err = simf(adapter)
+	default:
+		t.Fatal("adapter needs to be one of sim, socket, exec, docker")
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("Simulation with %d nodes passed in %s", len(result.Passes), result.FinishedAt.Sub(result.StartedAt))
+	var min, max time.Duration
+	var sum int
+	for _, pass := range result.Passes {
+		duration := pass.Sub(result.StartedAt)
+		if sum == 0 || duration < min {
+			min = duration
+		}
+		if duration > max {
+			max = duration
+		}
+		sum += int(duration.Nanoseconds())
+	}
+	t.Logf("Min: %s, Max: %s, Average: %s", min, max, time.Duration(sum/len(result.Passes))*time.Nanosecond)
+	finishedAt := time.Now()
+	t.Logf("Setup: %s, shutdown: %s", result.StartedAt.Sub(startedAt), finishedAt.Sub(result.FinishedAt))
+}
+
+func TestDeliveryFromNodes(t *testing.T) {
+	testSimulation(t, testDeliveryFromNodes)
+}
+
+var (
+	delivery    *Delivery
+	localStores []storage.ChunkStore
+	fileHash    storage.Key
+	nodeCount   int
+)
+
+func setLocalStores(n int) (func(), error) {
+	var datadirs []string
+	localStores = make([]storage.ChunkStore, n)
+	var err error
+	for i := 0; i < n; i++ {
+		// TODO: remove temp datadir after test
+		var datadir string
+		datadir, err = ioutil.TempDir("", "streamer")
+		if err != nil {
+			break
+		}
+		var localStore *storage.LocalStore
+		localStore, err = storage.NewTestLocalStore(datadir)
+		if err != nil {
+			break
+		}
+		datadirs = append(datadirs, datadir)
+		localStores[i] = localStore
+	}
+	teardown := func() {
+		for _, datadir := range datadirs {
+			os.RemoveAll(datadir)
+		}
+	}
+	return teardown, err
+}
+
+func mustReadAll(dpa *storage.DPA, hash storage.Key) (int, error) {
+	r := dpa.Retrieve(fileHash)
+	buf := make([]byte, 1024)
+	var n, total int
+	var err error
+	for (total == 0 || n > 0) && err == nil {
+		log.Warn(fmt.Sprintf("reading %v bytes at offset %v", len(buf), total))
+		n, err = r.ReadAt(buf, int64(total))
+		total += n
+	}
+	log.Warn(fmt.Sprintf("read %v bytes at offset %v", len(buf), total))
+	if err != nil && err != io.EOF {
+		return total, err
+	}
+	return total, nil
+}
+
+func testDeliveryFromNodes(adapter adapters.NodeAdapter) (*simulations.StepResult, error) {
+	nodes := 2
+	conns := 0
+	size := 8100
+	skipCheck := true
+
+	trigger := func(net *simulations.Network) chan discover.NodeID {
+		triggerC := make(chan discover.NodeID)
+		ticker := time.NewTicker(500 * time.Millisecond)
+		go func() {
+			defer ticker.Stop()
+			for range ticker.C {
+				triggerC <- net.Nodes[0].ID()
+			}
+		}()
+		return triggerC
+	}
+
+	action := func(net *simulations.Network) func(context.Context) error {
+		rrdpa := storage.NewDPA(newRoundRobinStore(localStores[1:]...), storage.NewChunkerParams())
+		rrdpa.Start()
+		dpacs := storage.NewDpaChunkStore(localStores[0].(*storage.LocalStore), func(chunk *storage.Chunk) error { return delivery.RequestFromPeers(chunk.Key[:], skipCheck) })
+		dpa := storage.NewDPA(dpacs, storage.NewChunkerParams())
+		dpa.Start()
+		return func(context.Context) error {
+			defer rrdpa.Stop()
+			hash, wait, err := rrdpa.Store(crand.Reader, int64(size))
+			if err != nil {
+				return err
+			}
+			wait()
+			fileHash = hash
+			go func() {
+				defer dpa.Stop()
+				log.Debug(fmt.Sprintf("retrieve %v", fileHash))
+				n, err := mustReadAll(dpa, fileHash)
+				log.Debug(fmt.Sprintf("retrieved %v", fileHash), "read", n, "err", err)
+			}()
+			return nil
+		}
+	}
+
+	check := func(net *simulations.Network, dpa *storage.DPA) func(ctx context.Context, id discover.NodeID) (bool, error) {
+		return func(ctx context.Context, id discover.NodeID) (bool, error) {
+			select {
+			case <-ctx.Done():
+				return false, ctx.Err()
+			default:
+			}
+			log.Warn(fmt.Sprintf("try to locally retrieve %v", fileHash))
+			total, err := mustReadAll(dpa, fileHash)
+			if err != nil || total != size {
+				log.Warn(fmt.Sprintf("number of bytes read %v/%v (error: %v)", total, size, err))
+				return false, nil
+			}
+			return true, nil
+			// node := net.GetNode(id)
+			// if node == nil {
+			// 	return false, fmt.Errorf("unknown node: %s", id)
+			// }
+			// client, err := node.Client()
+			// if err != nil {
+			// 	return false, fmt.Errorf("error getting node client: %s", err)
+			// }
+			// var response int
+			// if err := client.Call(&response, "test_haslocal", hash); err != nil {
+			// 	return false, fmt.Errorf("error getting bzz_has response: %s", err)
+			// }
+			// log.Debug(fmt.Sprintf("node has: %v\n%v", id, response))
+			// return response == 0, nil
+		}
+	}
+
+	result, err := runSimulation(nodes, conns, action, trigger, check, adapter)
+	if err != nil {
+		return nil, fmt.Errorf("Setting up simulation failed: %v", err)
+	}
+	if result.Error != nil {
+		return nil, fmt.Errorf("Simulation failed: %s", result.Error)
+	}
+	return result, err
+}
+
+func runSimulation(nodes, conns int, action func(*simulations.Network) func(context.Context) error, trigger func(*simulations.Network) chan discover.NodeID, check func(*simulations.Network, *storage.DPA) func(context.Context, discover.NodeID) (bool, error), adapter adapters.NodeAdapter) (*simulations.StepResult, error) {
+	// create network
+	net := simulations.NewNetwork(adapter, &simulations.NetworkConfig{
+		ID:             "0",
+		DefaultService: serviceName,
+	})
+	defer net.Shutdown()
+	teardown, err := setLocalStores(nodes)
+	defer teardown()
+	if err != nil {
+		return nil, err
+	}
+	ids := make([]discover.NodeID, nodes)
+	nodeCount = 0
+	for i := 0; i < nodes; i++ {
+		node, err := net.NewNode()
+		if err != nil {
+			return nil, fmt.Errorf("error starting node: %s", err)
+		}
+		if err := net.Start(node.ID()); err != nil {
+			return nil, fmt.Errorf("error starting node %s: %s", node.ID().TerminalString(), err)
+		}
+		ids[i] = node.ID()
+	}
+
+	// run a simulation which connects the 10 nodes in a ring and waits
+	// for full peer discovery
+	var addrs [][]byte
+	wg := sync.WaitGroup{}
+	for i := range ids {
+		// collect the overlay addresses, to
+		addrs = append(addrs, ToOverlayAddr(ids[i].Bytes()))
+		for j := 0; j < conns; j++ {
+			var k int
+			if j == 0 {
+				k = i - 1
+			} else {
+				k = rand.Intn(len(ids))
+			}
+			if i > 0 {
+				wg.Add(1)
+				go func(i, k int) {
+					defer wg.Done()
+					net.Connect(ids[i], ids[k])
+				}(i, k)
+			}
+		}
+	}
+	wg.Wait()
+	log.Debug(fmt.Sprintf("nodes: %v", len(addrs)))
+
+	// 64 nodes ~ 1min
+	// 128 nodes ~
+	dpa := storage.NewDPA(localStores[0], storage.NewChunkerParams())
+	dpa.Start()
+	timeout := 300 * time.Second
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	result := simulations.NewSimulation(net).Run(ctx, &simulations.Step{
+		Action:  action(net),
+		Trigger: trigger(net),
+		Expect: &simulations.Expectation{
+			Nodes: ids,
+			Check: check(net, dpa),
+		},
+	})
+	return result, nil
+}
+
+func newService(ctx *adapters.ServiceContext) (node.Service, error) {
+	id := ctx.Config.ID
+	addr := NewAddrFromNodeID(id)
+	kad := NewKademlia(addr.Over(), NewKadParams())
+	localStore := localStores[nodeCount]
+	dbAccess := NewDbAccess(localStore.(*storage.LocalStore))
+	streamer := NewStreamer(NewDelivery(kad, dbAccess))
+	if nodeCount == 0 {
+		delivery = streamer.delivery
+	}
+	nodeCount++
+	run := func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
+		bzzPeer := &bzzPeer{
+			Peer:      protocols.NewPeer(p, rw, StreamerSpec),
+			localAddr: addr,
+			BzzAddr:   NewAddrFromNodeID(p.ID()),
+		}
+		kad.On(bzzPeer)
+		streamer.Subscribe(p.ID(), retrieveRequestStream, nil, 0, 0, Top, true)
+		return streamer.Run(bzzPeer)
+	}
+
+	return &testDeliveryService{
+		run: run,
+	}, nil
+}
+
+type testDeliveryService struct {
+	run func(p *p2p.Peer, rw p2p.MsgReadWriter) error
+}
+
+func (tds *testDeliveryService) Protocols() []p2p.Protocol {
+	return []p2p.Protocol{
+		{
+			Name:    StreamerSpec.Name,
+			Version: StreamerSpec.Version,
+			Length:  StreamerSpec.Length(),
+			Run:     tds.run,
+			// NodeInfo: ,
+			// PeerInfo: ,
+		},
+	}
+}
+
+func (b *testDeliveryService) APIs() []rpc.API {
+	return []rpc.API{}
+}
+
+func (b *testDeliveryService) Start(server *p2p.Server) error {
+	return nil
+}
+
+func (b *testDeliveryService) Stop() error {
+	return nil
+}
diff --git a/swarm/network/streamer_test.go b/swarm/network/streamer_test.go
index 0d58d552c2..df1f92e3b5 100644
--- a/swarm/network/streamer_test.go
+++ b/swarm/network/streamer_test.go
@@ -25,16 +25,16 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/crypto/sha3"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/protocols"
 	p2ptest "github.com/ethereum/go-ethereum/p2p/testing"
 	"github.com/ethereum/go-ethereum/swarm/storage"
 )
 
-func init() {
-	log.Root().SetHandler(log.CallerFileHandler(log.LvlFilterHandler(log.LvlWarn, log.StreamHandler(os.Stderr, log.TerminalFormat(true)))))
-}
+//
+// func init() {
+// 	log.Root().SetHandler(log.CallerFileHandler(log.LvlFilterHandler(log.LvlWarn, log.StreamHandler(os.Stderr, log.TerminalFormat(true)))))
+// }
 
 // TODO: extract newStreamer
 func newStreamerTester(t *testing.T) (*p2ptest.ProtocolTester, *Streamer, *storage.LocalStore, func(), error) {
diff --git a/swarm/storage/dpa.go b/swarm/storage/dpa.go
index 5f0a95470e..508a712013 100644
--- a/swarm/storage/dpa.go
+++ b/swarm/storage/dpa.go
@@ -80,7 +80,7 @@ func NewLocalDPA(datadir string, basekey []byte) (*DPA, error) {
 }
 
 func NewDPA(store ChunkStore, params *ChunkerParams) *DPA {
-	chunker := NewTreeChunker(params)
+	chunker := NewPyramidChunker(params)
 	return &DPA{
 		Chunker:    chunker,
 		ChunkStore: store,
diff --git a/swarm/storage/pyramid.go b/swarm/storage/pyramid.go
index 28736cf319..5e160a7fed 100644
--- a/swarm/storage/pyramid.go
+++ b/swarm/storage/pyramid.go
@@ -136,10 +136,11 @@ func NewPyramidChunker(params *ChunkerParams) (self *PyramidChunker) {
 	return
 }
 
-func (self *PyramidChunker) Join(key Key, chunkC chan *Chunk) LazySectionReader {
+func (self *PyramidChunker) Join(key Key, chunkC chan *Chunk, depth int) LazySectionReader {
 	return &LazyChunkReader{
 		key:       key,
 		chunkC:    chunkC,
+		depth:     depth,
 		chunkSize: self.chunkSize,
 		branches:  self.branches,
 		hashSize:  self.hashSize,