Bug ID 597835: Branch parameter in inserted VIA header not consistent as per spec

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.1 HF10, 11.5.1 HF11, 11.5.2 HF1, 11.5.3 HF1, 11.5.3 HF2, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1

Fixed In:
13.0.0, 12.1.2, 11.6.1 HF2

Opened: Jun 07, 2016

Severity: 3-Major

Related Article: K12228503


MRF SIP in LoadBalancing Operation Mode inserts a VIA header to SIP request messages. This VIA header is removed from the returned response message. The VIA header contains encrypted routing information to route the response message. The SIP spec states that all messages in the same transaction should contain the same branch header. The code used to encrypt the branch field returns a different value each time.


Some servers have code to verify the brach fields in the VIA header do not change within a transaction. These servers complain when they see the fields change.


-- Enabling SIP Via header insertion on the BIG-IP system. -- SIP MRF profile. -- Need to cancel an INVITE.



Fix Information

The system now ensures the branch field in the via header does not change.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips