diff --git a/README.md b/README.md
index 078f8fc..03082cb 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
 # bc
 
 Own p2p network and own blockchain libraries written in Go, to develop own decentralized apps.
+
+The purpose of this code is to learn to develop a p2p network and a blockchain system.
diff --git a/peer/main.go b/peer/main.go
index 9f462a0..0b34144 100644
--- a/peer/main.go
+++ b/peer/main.go
@@ -30,8 +30,10 @@ func main() {
 	check(err)
 	blockchain.Print()
 
+	//initialize p2plib
+	configuredMsgCases := createMsgHandlerCases()
 	tp = p2plib.InitializePeer(os.Args[1], "127.0.0.1",
-		os.Args[2], os.Args[3], config.ServerIP, config.ServerPort)
+		os.Args[2], os.Args[3], config.ServerIP, config.ServerPort, configuredMsgCases)
 
 	if tp.RunningPeer.Role == "client" {
 		color.Red("http://" + config.IP + ":" + config.ServerRESTPort)
diff --git a/peer/messageHandler.go b/peer/messageHandler.go
new file mode 100644
index 0000000..9c2bdec
--- /dev/null
+++ b/peer/messageHandler.go
@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+
+	p2plib "./p2plib"
+
+	blockchainlib "./blockchainlib"
+)
+
+func createMsgHandlerCases() map[string]func(p2plib.Peer, p2plib.Msg) {
+	configuredMsgCases := make(map[string]func(p2plib.Peer, p2plib.Msg))
+	configuredMsgCases["Block"] = func(peer p2plib.Peer, msg p2plib.Msg) {
+		//TODO check if the block is signed by an autorized emitter
+		//block = msg.Data converted to Block
+		var block blockchainlib.Block
+		if !blockchain.BlockExists(block) {
+			blockchain.AddBlock(block)
+			p2plib.PropagateData(peer, "block in string format")
+		}
+	}
+
+	fmt.Println(configuredMsgCases)
+	return configuredMsgCases
+}
diff --git a/peer/p2plib/init.go b/peer/p2plib/init.go
index 7e66149..15c04cb 100644
--- a/peer/p2plib/init.go
+++ b/peer/p2plib/init.go
@@ -4,12 +4,17 @@ import (
 	"fmt"
 	"math/rand"
 	"time"
+
+	"github.com/fatih/color"
 )
 
-func InitializePeer(role, ip, port, restport, serverip, serverport string) ThisPeer {
+func InitializePeer(role, ip, port, restport, serverip, serverport string,
+	configuredMsgCases map[string]func(Peer, Msg)) ThisPeer {
 	//initialize some vars
 	rand.Seed(time.Now().Unix())
 
+	InitializeDefaultMsgCases(configuredMsgCases)
+
 	var tp ThisPeer
 	tp.Running = true
 	tp.RunningPeer.Role = role
@@ -41,3 +46,35 @@ func InitializePeer(role, ip, port, restport, serverip, serverport string) ThisP
 	return tp
 
 }
+
+func InitializeDefaultMsgCases(configuredMsgCases map[string]func(Peer, Msg)) {
+	//msgCases := make(map[string]func(Peer, Msg)) --> no, it's used the global
+	msgCases = make(map[string]func(Peer, Msg))
+
+	//get the user configured msgCases
+	for k, v := range configuredMsgCases {
+		msgCases[k] = v
+	}
+
+	msgCases["Hi"] = func(peer Peer, msg Msg) {
+		color.Yellow(msg.Type)
+		color.Green(msg.Content)
+	}
+
+	msgCases["PeersList"] = func(peer Peer, msg Msg) {
+		color.Blue("newPeerslist")
+		fmt.Println(msg.PeersList)
+		color.Red("PeersList")
+
+		UpdateNetworkPeersList(peer.Conn, msg.PeersList)
+		PropagatePeersList(peer)
+		PrintPeersList()
+	}
+
+	msgCases["Data"] = func(peer Peer, msg Msg) {
+		color.Yellow(msg.Type)
+		color.Green(msg.Content)
+		PropagateData(peer, "data")
+	}
+	fmt.Println(msgCases)
+}
diff --git a/peer/p2plib/messages.go b/peer/p2plib/messages.go
index 3a8e507..be8f40a 100644
--- a/peer/p2plib/messages.go
+++ b/peer/p2plib/messages.go
@@ -2,11 +2,8 @@ package p2plib
 
 import (
 	"encoding/json"
-	"fmt"
 	"log"
 	"time"
-
-	"github.com/fatih/color"
 )
 
 type Msg struct {
@@ -17,46 +14,24 @@ type Msg struct {
 	Data      []byte    `json:"data"`
 }
 
+type Case struct {
+	Case     string
+	Function func(Peer, Msg)
+}
+
+var msgCases map[string]func(Peer, Msg)
+
 func MessageHandler(peer Peer, msg Msg) {
 
 	log.Println("[New msg]")
 	log.Println(msg)
 
-	switch msg.Type {
-	case "Hi":
-		color.Yellow(msg.Type)
-		color.Green(msg.Content)
-		break
-	case "PeersList":
-		color.Blue("newPeerslist")
-		fmt.Println(msg.PeersList)
-		color.Red("PeersList")
-
-		UpdateNetworkPeersList(peer.Conn, msg.PeersList)
-		PropagatePeersList(peer)
-		PrintPeersList()
-		break
-	case "PeersList_Response":
-		//for the moment is not beeing used
-		color.Blue("newPeerslist, from PeersList_Response")
-		fmt.Println(msg.PeersList)
-		color.Red("PeersList_Response")
-
-		UpdateNetworkPeersList(peer.Conn, msg.PeersList)
-		PropagatePeersList(peer)
-		PrintPeersList()
-		break
-	case "Block":
-		/*//TODO check if the block is signed by an autorized emitter
-		if !blockchain.blockExists(msg.Block) {
-			blockchain.addBlock(msg.Block)
-			propagateBlock(msg.Block)
-		}*/
-		break
-	default:
-		log.Println("Msg.Type not supported")
-		break
-	}
+	/*for c, caseFunction := range msgCases {
+		if msg.Type == c {
+			caseFunction(peer, msg)
+		}
+	}*/
+	msgCases[msg.Type](peer, msg)
 
 }
 func (msg *Msg) Construct(msgtype string, msgcontent string) {
diff --git a/peer/p2plib/peers.go b/peer/p2plib/peers.go
index a67e7c1..db623b6 100644
--- a/peer/p2plib/peers.go
+++ b/peer/p2plib/peers.go
@@ -147,6 +147,21 @@ func PrintPeersList() {
 	}
 	fmt.Println("")
 }
+func PropagateData(p Peer, s string) {
+	//prepare the msg to send to all connected peers
+	var msg Msg
+	msg.Construct("Data", "new Data")
+	msg.Data = []byte(s)
+	msgB := msg.ToBytes()
+	for _, peer := range globalTP.PeersConnections.Outcoming.Peers {
+		if peer.Conn != nil {
+			if peer.ID != p.ID && p.ID != "" {
+				_, err := peer.Conn.Write(msgB)
+				check(err)
+			}
+		}
+	}
+}
 
 //send the block to all the peers of the outcomingPeersList
 /*func PropagateBlock(b Block) {
diff --git a/peer/p2plib/petitions.go b/peer/p2plib/petitions.go
new file mode 100644
index 0000000..c0e4f49
--- /dev/null
+++ b/peer/p2plib/petitions.go
@@ -0,0 +1,6 @@
+package p2plib
+
+func SendPetition(peer Peer, petition string) {
+	_, err := peer.Conn.Write([]byte(petition))
+	check(err)
+}