diff --git a/cs/cs.go b/cs/cs.go
index b9a2412..4435b8c 100644
--- a/cs/cs.go
+++ b/cs/cs.go
@@ -3,6 +3,7 @@ package cs
 import (
 	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"net/http/httputil"
 	"strings"
@@ -21,12 +22,13 @@ import (
 type ChargePointRequestMetadata struct {
 	ChargePointID string
 	HTTPRequest   *http.Request
+	Host          string
 }
 
 // ChargePointMessageHandler handles the OCPP messages coming from the charger
 type ChargePointMessageHandler func(cprequest cpreq.ChargePointRequest, metadata ChargePointRequestMetadata) (cpresp.ChargePointResponse, error)
 
-type ChargePointConnectionListener func(cpID string)
+type ChargePointConnectionListener func(cpID string, host string)
 type CentralSystem interface {
 	// Run the central system on the given port
 	// and handles each incoming ChargepointRequest
@@ -63,8 +65,8 @@ func New() CentralSystem {
 		connChans:       make(map[string]chan struct{}, 0),
 		connsCount:      make(map[string]int, 0),
 		connsConnected:  make(map[string]bool, 0),
-		connListener:    func(cpID string) {},
-		disconnListener: func(cpID string) {},
+		connListener:    func(cpID string, host string) {},
+		disconnListener: func(cpID string, host string) {},
 	}
 }
 
@@ -94,7 +96,12 @@ func (csys *centralSystem) Run(port string, cphandler ChargePointMessageHandler)
 
 func (csys *centralSystem) handleWebsocket(w http.ResponseWriter, r *http.Request, cphandler ChargePointMessageHandler) {
 	log.Debug("Current WS connections map: %v", csys.conns)
-	cpID := strings.TrimPrefix(r.URL.Path, "/")
+	host, _, _ := net.SplitHostPort(r.Host)
+	if host == "" {
+		host = r.Host
+	}
+	cpID := strings.Trim(r.URL.Path, "/")
+	cpID = host + ":" + cpID
 
 	rawReq, _ := httputil.DumpRequest(r, true)
 	log.Debug("Raw WS request: %s", string(rawReq))
@@ -118,12 +125,12 @@ func (csys *centralSystem) handleWebsocket(w http.ResponseWriter, r *http.Reques
 	csys.connMux.Unlock()
 
 	log.Debug("Connected with %s", cpID)
-	go csys.connListener(cpID)
+	go csys.connListener(cpID, host)
 
 	defer func() {
 		conn.Close()
 		log.Debug("Closed connection of: %s", cpID)
-		go csys.disconnListener(cpID)
+		go csys.disconnListener(cpID, host)
 		csys.connMux.Lock()
 		csys.connsCount[cpID]--
 		// if the same CP connected more times before we do the
@@ -147,6 +154,7 @@ func (csys *centralSystem) handleWebsocket(w http.ResponseWriter, r *http.Reques
 			cpresponse, err := cphandler(cprequest, ChargePointRequestMetadata{
 				ChargePointID: cpID,
 				HTTPRequest:   r,
+				Host:          host,
 			})
 			err = conn.SendResponse(req.MessageID, cpresponse, err)
 			if err != nil {
diff --git a/messages/req/actions.go b/messages/req/actions.go
index d7a5f17..0adffa7 100644
--- a/messages/req/actions.go
+++ b/messages/req/actions.go
@@ -13,8 +13,8 @@ func FromActionName(action string) messages.Request {
 	case "BootNotification":
 		return &cpreq.BootNotification{}
 	// TODO: DataTransfer comes from both the CS and CP
-	// case "DataTransfer":
-	// 	return &cpreq.DataTransfer{}
+	case "DataTransfer":
+		return &cpreq.DataTransfer{}
 	case "DiagnosticsStatusNotification":
 		return &cpreq.DiagnosticsStatusNotification{}
 	case "FirmwareStatusNotification":
diff --git a/messages/res/actions.go b/messages/res/actions.go
index e511c9c..d9d1b8f 100644
--- a/messages/res/actions.go
+++ b/messages/res/actions.go
@@ -53,8 +53,8 @@ func FromActionName(action string) messages.Response {
 	case "BootNotification":
 		return &cpresp.BootNotification{}
 	// TODO: DataTransfer comes from both the CS and CP
-	// case "DataTransfer":
-	// 	return &cpresp.DataTransfer{}
+	case "DataTransfer":
+		return &cpresp.DataTransfer{}
 	case "DiagnosticsStatusNotification":
 		return &cpresp.DiagnosticsStatusNotification{}
 	case "FirmwareStatusNotification":
diff --git a/ocpp_test.go b/ocpp_test.go
index cc0f5a3..7ff6376 100644
--- a/ocpp_test.go
+++ b/ocpp_test.go
@@ -25,11 +25,11 @@ func Test_Connection(t *testing.T) {
 
 	csysPort := ":5050"
 	csys := cs.New()
-	csys.SetChargePointConnectionListener(func(cpID string) {
+	csys.SetChargePointConnectionListener(func(cpID string, host string) {
 		// t.Log("cpoint connected: ", cpID)
 		cpointConnected <- cpID
 	})
-	csys.SetChargePointDisconnectionListener(func(cpID string) {
+	csys.SetChargePointDisconnectionListener(func(cpID string, host string) {
 		// t.Log("cpoint disconnected: ", cpID)
 		cpointDisconnected <- cpID
 	})
diff --git a/ws/conn.go b/ws/conn.go
index b85bc00..8804b9c 100644
--- a/ws/conn.go
+++ b/ws/conn.go
@@ -182,6 +182,7 @@ func (c *Conn) ReadMessage() error {
 	log.Debug("Received a message, raw: %v", string(messageBytes))
 	msg, err := UnmarshalMessage(messageBytes)
 	if err != nil {
+		log.Error("unmarshal error=%v", err)
 		return err
 	}
 
@@ -234,6 +235,7 @@ func (c *Conn) callToRequest(call *CallMessage) (messages.Request, ErrorCode) {
 	}
 	err = json.Unmarshal(originalPayload, req)
 	if err != nil {
+		fmt.Println(err)
 		return nil, FormationViolation
 	}
 	return req, Nil