Last Modified: Jul 18, 2026
Affected Product(s):
BIG-IP CGN
Known Affected Versions:
11.5.1, 11.5.1 hf1, 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, 11.5.2 hf1, 11.5.3, 11.5.3 hf1, 11.5.3 hf2, 11.5.4, 11.5.4 hf1, 11.5.4 hf2, 11.5.4 hf3, 11.5.4 hf4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10
Fixed In:
11.6.0
Opened: May 21, 2013 Severity: 2-Critical Related Article:
K15993
SIP messages are sent directly to the peer and not to the SIP-Proxy when both peers are inside the NAT.
Some SIP messages may not be seen by the SIP-Proxy and cause missed messages and accounting gaps.
-- CGNAT and SIP-ALG are configured. -- Peer1 and Peer2 are in the NAT'd network (subscribers). -- SIP-Proxy is located outside the NAT network (internet).
None
SIP messages through the SIP-ALG are no longer hairpinned when the destination address is not inside the NAT.