Port in contact header of 200 Ok from IMSDROID is being changed. This port is not same as the port where INVITE was sent. Problem arises while sening ACK to IMSDROID from SIPp.


What steps will reproduce the problem?
1.Send Invite from sipp, Sipp gets 200 Ok message from IMSDROID.
2. Port in 200 Ok is different to which Invite was sent.
3. Ack is unreachable to IMSDROID.

What is the expected output? What do you see instead?
How to send ACK to IMSDROID on the port received in contact header of 200 Ok 
message.

What version of the product are you using? On what operating system?
IMSDroid/v2.0.453 on Android OS.

Please provide any additional information below.
REGISTER sip:doubango.org SIP/2.0
Via: SIP/2.0/UDP 10.0.2.15:39307;branch=z9hG4bK2017126983;rport
From: <sip:rahusin@doubango.org>;tag=1980742754
To: <sip:rahusin@doubango.org>
Contact: 
sip:rahusin@10.0.2.15:39307;transport=udp>;expires=1700;+g.oma.sip-im;language="
en,fr";+g.3gpp.smsip;+g.oma.sip-im.large-message;audio;+g.3gpp.icsi-ref="urn%3Au
rn-7%3A3gpp-application.ims.iari.gsma-vs";+g.3gpp.cs-voice

Call-ID: 433400ff-b23e-8fcb-c5ea-89bc6564d3da

CSeq: 232177567 REGISTER

Content-Length: 0

Max-Forwards: 70

Authorization: Digest 
username="rahusin",realm="doubango.org",nonce="",uri="sip:doubango.org",response
=""

Allow: INVITE, ACK, CANCEL, BYE, MESSAGE, OPTIONS, NOTIFY, PRACK, UPDATE, REFER

Privacy: none

P-Access-Network-Info: ADSL;utran-cell-id-3gpp=00000000

User-Agent: IM-client/OMA1.0 android-ngn-stack/v2.0.453 (doubango r653)

P-Preferred-Identity: <sip:rahusin@doubango.org>

Supported: path

SIP/2.0 200 OK

Via: SIP/2.0/UDP 10.0.2.15:39307;branch=z9hG4bK2017126983;rport

From: <sip:rahusin@doubango.org>;tag=1980742754

To: <sip:rahusin@doubango.org>;tag=2222

Call-ID: 433400ff-b23e-8fcb-c5ea-89bc6564d3da

CSeq: 232177567 REGISTER

Contact: sip:user2@10.76.205.240:5090;transport=UDP

INVITE sip:rahusin@10.76.205.187 SIP/2.0

Via: SIP/2.0/UDP 10.76.205.240:5090;branch=z9hG4bK-6162-1-0-6162

From: rahul <sip:rahul@10.76.205.240>;tag=a57ddeb8bdd6ff12

To: <sip:rahusin@10.76.205.187>

Contact: <sip:rahul@10.76.205.240:5090;transport=UDP;user=phone>

Supported: replaces

Call-ID: 1-6162@10.76.205.240

CSeq: 55257 INVITE

User-Agent: Grandstream BT100 1.0.6.7

Max-Forwards: 70

Allow: INVITE,ACK,CANCEL,BYE,NOTIFY,REFER,OPTIONS,INFO,SUBSCRIBE

Content-Type: application/sdp

Session-Expires: 3600

Content-Length: 197

v=0

o=doubango 1983 678901 IN IP4 10.0.2.15

s=-

c=IN IP4 10.0.2.15

t=0 0

m=audio 55320 RTP/AVP 8 101

a=ptime:20

a=rtpmap:8 PCMA/8000/1

a=rtpmap:101 telephone-event/8000/1

a=fmtp:101 0-15SIP/2.0 100 Trying (sent from the Transaction Layer)

Via: SIP/2.0/UDP 10.76.205.240:5090;branch=z9hG4bK-6162-1-0-6162

From: "rahul "<sip:rahul@10.76.205.240>;tag=a57ddeb8bdd6ff12

To: <sip:rahusin@10.76.205.187>

Call-ID: 1-6162@10.76.205.240

CSeq: 55257 INVITE

Content-Length: 0

SIP/2.0 180 Ringing

Via: SIP/2.0/UDP 10.76.205.240:5090;branch=z9hG4bK-6162-1-0-6162

From: "rahul "<sip:rahul@10.76.205.240>;tag=a57ddeb8bdd6ff12

To: <sip:rahusin@10.76.205.187>;tag=728496906

Contact: <sip:rahusin@10.0.2.15:39455;transport=udp>

Call-ID: 1-6162@10.76.205.240

CSeq: 55257 INVITE

Content-Length: 0

Allow: ACK, BYE, CANCEL, INVITE, MESSAGE, NOTIFY, OPTIONS, PRACK, REFER, UPDATE

SIP/2.0 200 Ok

Via: SIP/2.0/UDP 10.76.205.240:5090;branch=z9hG4bK-6162-1-0-6162

From: "rahul "<sip:rahul@10.76.205.240>;tag=a57ddeb8bdd6ff12

To: <sip:rahusin@10.76.205.187>;tag=728496906

Contact: <sip:rahusin@10.0.2.15:39455;transport=udp>

Call-ID: 1-6162@10.76.205.240

CSeq: 55257 INVITE

Allow: ACK, BYE, CANCEL, INVITE, MESSAGE, NOTIFY, OPTIONS, PRACK, REFER, UPDATE

Content-type: application/sdp
Content-Length: 197

v=0
o=doubango 1983 678901 IN IP4 10.0.2.15
s=-
c=IN IP4 10.0.2.15
t=0 0
m=audio 55320 RTP/AVP 8 101
a=ptime:20
a=rtpmap:8 PCMA/8000/1

Original issue reported on code.google.com by rahulsin...@gmail.com on 20 Jan 2012 at 6:29

Fahed123 / imsdroid

Port in contact header of 200 Ok from IMSDROID is being changed. This port is not same as the port where INVITE was sent. Problem arises while sening ACK to IMSDROID from SIPp. #321