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B2BUA: ACK for RE-INVITE contains wrong branch

7 posts · Brekeke SIP Server Forum

Lambert98 Original post
1. Brekeke Product Name and version:
SIP Server 2.37.4
2. Java version:

3. OS type and the version:

4. UA (phone), gateway or other hardware/software involved:

5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/ ... terns.html :

6. Your problem:
The ACK for a RE_INVITE contains same branch as the RE_INVITE
-> same transaction : ACK is ignored and OK is send until timeout

Traces:
initial INVITE:

ZGvE5}L3INVITE sip:5006@172.24.5.159;transport=UDP SIP/2.0
Via: SIP/2.0/UDP 172.24.5.160:5060;branch=z9hG4bK-d8754z-15149f755fde85e7-1---d8754z-

!ZGE+as*INVITE sip:5006@172.24.5.154:5070 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.159:5060;rport;branch=z9hG4bKa8993331addb381431c22-64254860-e2c0d829

ZG!E@SIP/2.0 200 OK
Via: SIP/2.0/UDP 172.24.5.159:5060;rport=5060;branch=z9hG4bKa8993331addb381431c22-64254860-e2c0d829;received=172.24.5.159

vZGE+SS5SIP/2.0 200 OK
Via: SIP/2.0/UDP 172.24.5.160:5060;branch=z9hG4bK-d8754z-15149f755fde85e7-1---d8754z-

ZGvE@eTIACK sip:5006@172.24.5.159:5060 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.160:5060;branch=z9hG4bK-d8754z-4618044a1c18d3d3-1---d8754z-

!ZGE,%ACK sip:5006@172.24.5.154:5070 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.159:5060;rport;branch=z9hG4bK94fca43df022561431c22-64254860-a14c453d


Re-INVITE

ZGvEAwC+INVITE sip:5006@172.24.5.159:5060 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.160:5060;branch=z9hG4bK-d8754z-e869f48e9f027bc4-1---d8754z-

!ZGE*'INVITE sip:5006@172.24.5.154:5070 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.159:5060;rport;branch=z9hG4bKcbe79e218904f51431c22-64254860-15c73934

ZG!E0@USIP/2.0 200 OK
Via: SIP/2.0/UDP 172.24.5.159:5060;rport=5060;branch=z9hG4bKcbe79e218904f51431c22-64254860-15c73934;received=172.24.5.159

vZGE*JSIP/2.0 200 OK
Via: SIP/2.0/UDP 172.24.5.160:5060;branch=z9hG4bK-d8754z-e869f48e9f027bc4-1---d8754z-

ZGvE[JACK sip:5006@172.24.5.159:5060 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.160:5060;branch=z9hG4bK-d8754z-4ae409aee10d745c-1---d8754z-

!ZGE+xACK sip:5006@172.24.5.154:5070 SIP/2.0
Via: SIP/2.0/UDP 172.24.5.159:5060;rport;branch=z9hG4bKcbe79e218904f51431c22-64254860-15c73934
tuie2
Who sent such an ACK packet?

Can you post these packets in http://pcapr.net/?
Lambert98
tuie2
Lambert98,
I will look at it.
tuie2
Does the same issue happen even if you don't use B2B UA mode at Brekeke SIP Server?
Lambert98
No -- in 'normal' mode it works well. The ACK's are correct. Everything is working as expected
tuie2
I checked it with a Brekeke developer.
He said it is a bug in the B2B-UA mode.

It will be fixed in a future version.