Symptom
A Session Initiation Protocol (SIP) phone is not able to register to a Private Branch Exchange (PBX) service through Network Address Translation (NAT).
Conditions
A phone sends SIP traffic through a router with NAT enabled:
Phone+---->Switch+---->Router w/NAT +---->Internet+---->PBX
The communication fails because NAT is not able to send back the traffic to the IP phone. There is evidence of unidirectional traffic.
Workaround
Run:
configure terminal
no ip nat service all-algs
exit
clear ip nat trans *
Further Problem Description
To gather the NAT debugs run:
debug platform hardware qfp active feature nat datapath all
request platform software trace rotate all
archive tar /create tar_tracelogs.tar bootflash:/tracelogs/
Send the tracelogs to TAC to be decoded, the information stored in the 'CPP_CP_F#' contains the NAT debugs.
This bug was found in a device with Quantum Flow Processor (QFP)
