diff --git a/pkg/auth/server.go b/pkg/auth/server.go
index e3ab3c7..8929f6a 100644
--- a/pkg/auth/server.go
+++ b/pkg/auth/server.go
@@ -8,7 +8,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/cloudwebrtc/go-sip-ua/pkg/util"
 	"github.com/ghettovoice/gosip/log"
 	"github.com/ghettovoice/gosip/sip"
 )
@@ -108,9 +107,7 @@ func (auth *ServerAuthorizer) requestAuthentication(request sip.Request, tx sip.
 		created: time.Now(),
 	}
 	response.SetBody("", true)
-	util.BuildContactHeader("Contact", request, response, nil)
 	tx.Respond(response)
-	return
 }
 
 func (auth *ServerAuthorizer) checkAuthorization(request sip.Request, tx sip.ServerTransaction,
diff --git a/pkg/session/session.go b/pkg/session/session.go
index 070e60e..0646de0 100644
--- a/pkg/session/session.go
+++ b/pkg/session/session.go
@@ -10,7 +10,7 @@ import (
 	gosip_util "github.com/ghettovoice/gosip/util"
 )
 
-type RequestCallback func(ctx context.Context, request sip.Request, authorizer sip.Authorizer, waitForResult bool) (sip.Response, error)
+type RequestCallback func(ctx context.Context, request sip.Request, authorizer sip.Authorizer, waitForResult bool, attempt int) (sip.Response, error)
 
 type Session struct {
 	lock           sync.Mutex
@@ -240,7 +240,7 @@ func (s *Session) Bye() {
 
 func (s *Session) sendRequest(req sip.Request) (sip.Response, error) {
 	s.Log().Debugf(s.uaType+" send request: %v => \n%v", req.Method(), req)
-	return s.requestCallbck(context.TODO(), req, nil, false)
+	return s.requestCallbck(context.TODO(), req, nil, false, 1)
 }
 
 // Reject Reject incoming call or for re-INVITE or UPDATE,
@@ -249,6 +249,7 @@ func (s *Session) Reject(statusCode sip.StatusCode, reason string) {
 	request := s.request
 	s.Log().Debugf("Reject: Request => %s, body => %s", request.Short(), request.Body())
 	response := sip.NewResponseFromRequest(request.MessageID(), request, statusCode, reason, "")
+	response.AppendHeader(s.localURI.AsContactHeader())
 	tx.Respond(response)
 }
 
@@ -346,7 +347,7 @@ func (s *Session) Provisional(statusCode sip.StatusCode, reason string) {
 	} else {
 		response = sip.NewResponseFromRequest(request.MessageID(), request, statusCode, reason, "")
 	}
-
+	response.AppendHeader(s.localURI.AsContactHeader())
 	s.response = response
 	tx.Respond(response)
 }
@@ -370,14 +371,21 @@ func (s *Session) makeRequest(uaType string, method sip.RequestMethod, msgID sip
 	to := s.remoteURI.Clone().AsToHeader()
 	newRequest.AppendHeader(to)
 	newRequest.SetRecipient(s.request.Recipient())
+	sip.CopyHeaders("Via", inviteRequest, newRequest)
 
 	if uaType == "UAC" {
-		sip.CopyHeaders("Via", inviteRequest, newRequest)
+		if contact, ok := s.request.Contact(); ok {
+			newRequest.AppendHeader(contact)
+		}
+
 		if len(inviteRequest.GetHeaders("Route")) > 0 {
 			sip.CopyHeaders("Route", inviteRequest, newRequest)
 		}
 	} else if uaType == "UAS" {
-		sip.CopyHeaders("Via", inviteRequest, newRequest)
+		if contact, ok := s.response.Contact(); ok {
+			newRequest.AppendHeader(contact)
+		}
+
 		if len(inviteResponse.GetHeaders("Route")) > 0 {
 			sip.CopyHeaders("Route", inviteResponse, newRequest)
 		}
@@ -389,6 +397,7 @@ func (s *Session) makeRequest(uaType string, method sip.RequestMethod, msgID sip
 	newRequest.AppendHeader(&maxForwardsHeader)
 	sip.CopyHeaders("Call-ID", inviteRequest, newRequest)
 	sip.CopyHeaders("CSeq", inviteRequest, newRequest)
+
 	cseq, _ := newRequest.CSeq()
 	cseq.SeqNo++
 	cseq.MethodName = method
diff --git a/pkg/stack/stack.go b/pkg/stack/stack.go
index a7f003f..7d1d3cc 100644
--- a/pkg/stack/stack.go
+++ b/pkg/stack/stack.go
@@ -334,7 +334,6 @@ func (s *SipStack) AckInviteRequest(request sip.Request, response sip.Response)
 	ackRequest := sip.NewAckRequest("", request, response, "", log.Fields{
 		"sent_at": time.Now(),
 	})
-	ackRequest.SetRecipient(request.Recipient())
 	if err := s.Send(ackRequest); err != nil {
 		s.Log().WithFields(map[string]interface{}{
 			"invite_request":  request.Short(),
@@ -348,7 +347,6 @@ func (s *SipStack) CancelRequest(request sip.Request, response sip.Response) {
 	cancelRequest := sip.NewCancelRequest("", request, log.Fields{
 		"sent_at": time.Now(),
 	})
-	cancelRequest.SetRecipient(request.Recipient())
 	if err := s.Send(cancelRequest); err != nil {
 		s.Log().WithFields(map[string]interface{}{
 			"invite_request":  request.Short(),
diff --git a/pkg/ua/register.go b/pkg/ua/register.go
index 463c5b6..2fdd138 100644
--- a/pkg/ua/register.go
+++ b/pkg/ua/register.go
@@ -76,7 +76,7 @@ func (r *Register) SendRegister(expires uint32) error {
 		r.authorizer = auth.NewClientAuthorizer(profile.AuthInfo.AuthUser, profile.AuthInfo.Password)
 	}
 
-	resp, err := ua.RequestWithContext(r.ctx, *r.request, r.authorizer, true)
+	resp, err := ua.RequestWithContext(r.ctx, *r.request, r.authorizer, true, 1)
 
 	if err != nil {
 		ua.Log().Errorf("Request [%s] failed, err => %v", sip.REGISTER, err)
diff --git a/pkg/ua/ua.go b/pkg/ua/ua.go
index 2d39891..e4f06aa 100644
--- a/pkg/ua/ua.go
+++ b/pkg/ua/ua.go
@@ -3,7 +3,7 @@ package ua
 import (
 	"context"
 	"fmt"
-	"net"
+	"strconv"
 	"sync"
 
 	"github.com/cloudwebrtc/go-sip-ua/pkg/account"
@@ -102,32 +102,6 @@ func (ua *UserAgent) buildRequest(
 	return &req, nil
 }
 
-func (ua *UserAgent) buildViaHopHeader(target sip.SipUri) *sip.ViaHop {
-	protocol := "udp"
-	if nt, ok := target.UriParams().Get("transport"); ok {
-		protocol = nt.String()
-	}
-	s := ua.config.SipStack
-	netinfo := s.GetNetworkInfo(protocol)
-
-	var host string = netinfo.Host
-	if net.ParseIP(target.Host()).IsLoopback() {
-		host = "127.0.0.1"
-	}
-
-	port := netinfo.Port
-
-	viaHop := &sip.ViaHop{
-		ProtocolName:    "SIP",
-		ProtocolVersion: "2.0",
-		Transport:       protocol,
-		Host:            host,
-		Port:            port,
-		Params:          sip.NewParams().Add("branch", sip.String{Str: sip.GenerateBranch()}),
-	}
-	return viaHop
-}
-
 func (ua *UserAgent) SendRegister(profile *account.Profile, recipient sip.SipUri, expires uint32, userdata interface{}) (*Register, error) {
 	register := NewRegister(ua, profile, recipient, userdata)
 	err := register.SendRegister(expires)
@@ -169,7 +143,7 @@ func (ua *UserAgent) Invite(profile *account.Profile, target sip.Uri, recipient
 		authorizer = auth.NewClientAuthorizer(profile.AuthInfo.AuthUser, profile.AuthInfo.Password)
 	}
 
-	resp, err := ua.RequestWithContext(context.TODO(), *request, authorizer, false)
+	resp, err := ua.RequestWithContext(context.TODO(), *request, authorizer, false, 1)
 	if err != nil {
 		ua.Log().Errorf("INVITE: Request [INVITE] failed, err => %v", err)
 		return nil, err
@@ -188,7 +162,7 @@ func (ua *UserAgent) Invite(profile *account.Profile, target sip.Uri, recipient
 		}
 	}
 
-	return nil, fmt.Errorf("Invite session not found, unknown errors.")
+	return nil, fmt.Errorf("invite session not found, unknown errors")
 }
 
 func (ua *UserAgent) Request(req *sip.Request) (sip.ClientTransaction, error) {
@@ -198,6 +172,32 @@ func (ua *UserAgent) Request(req *sip.Request) (sip.ClientTransaction, error) {
 func (ua *UserAgent) handleBye(request sip.Request, tx sip.ServerTransaction) {
 	ua.Log().Debugf("handleBye: Request => %s, body => %s", request.Short(), request.Body())
 	response := sip.NewResponseFromRequest(request.MessageID(), request, 200, "OK", "")
+
+	if viaHop, ok := request.ViaHop(); ok {
+		var (
+			host string
+			port sip.Port
+		)
+		host = viaHop.Host
+		if viaHop.Params != nil {
+			if received, ok := viaHop.Params.Get("received"); ok && received.String() != "" {
+				host = received.String()
+			}
+			if rport, ok := viaHop.Params.Get("rport"); ok && rport != nil && rport.String() != "" {
+				if p, err := strconv.Atoi(rport.String()); err == nil {
+					port = sip.Port(uint16(p))
+				}
+			} else if request.Recipient().Port() != nil {
+				port = *request.Recipient().Port()
+			} else {
+				port = sip.DefaultPort(request.Transport())
+			}
+		}
+
+		dest := fmt.Sprintf("%v:%v", host, port)
+		response.SetDestination(dest)
+	}
+
 	tx.Respond(response)
 	callID, ok := request.CallID()
 	if ok {
@@ -290,7 +290,7 @@ func (ua *UserAgent) handleInvite(request sip.Request, tx sip.ServerTransaction)
 }
 
 // RequestWithContext .
-func (ua *UserAgent) RequestWithContext(ctx context.Context, request sip.Request, authorizer sip.Authorizer, waitForResult bool) (sip.Response, error) {
+func (ua *UserAgent) RequestWithContext(ctx context.Context, request sip.Request, authorizer sip.Authorizer, waitForResult bool, attempt int) (sip.Response, error) {
 	s := ua.config.SipStack
 	tx, err := s.Request(request)
 	if err != nil {
@@ -401,12 +401,13 @@ func (ua *UserAgent) RequestWithContext(ctx context.Context, request sip.Request
 				}
 
 				// unauth request
-				if (response.StatusCode() == 401 || response.StatusCode() == 407) && authorizer != nil {
+				needAuth := (response.StatusCode() == 401 || response.StatusCode() == 407) && attempt < 2
+				if needAuth && authorizer != nil {
 					if err := authorizer.AuthorizeRequest(request, response); err != nil {
 						errs <- err
 						return
 					}
-					if response, err := ua.RequestWithContext(ctx, request, nil, true); err == nil {
+					if response, err := ua.RequestWithContext(ctx, request, authorizer, true, attempt+1); err == nil {
 						responses <- response
 					} else {
 						errs <- err
@@ -455,7 +456,6 @@ func (ua *UserAgent) RequestWithContext(ctx context.Context, request sip.Request
 					if v, found := ua.iss.Load(*callID); found {
 						is := v.(*session.Session)
 						ua.iss.Delete(*callID)
-						// handle Ringing or Processing with sdp
 						is.SetState(session.Failure)
 						ua.handleInviteState(is, &request, &response, session.Failure, nil)
 					}
@@ -466,7 +466,6 @@ func (ua *UserAgent) RequestWithContext(ctx context.Context, request sip.Request
 				if ok {
 					if v, found := ua.iss.Load(*callID); found {
 						if request.IsInvite() {
-							// handle Ringing or Processing with sdp
 							is := v.(*session.Session)
 							is.SetState(session.Confirmed)
 							ua.handleInviteState(is, &request, &response, session.Confirmed, nil)