During the setup of some calls (approx. 1 in 600) a SIP invite is sent from the customer towards the
SBC and eventually towards the PGW. The PGW after the expected messages responds with a SIP OK
towards the SBC with SDP containing the info for the remote media endpoint (in this case a Cisco MGX
VXSM blade). Packet captures have shown the address that is sent out of the PGW and towards the SBC
is what is expected. However, the SBC shows a different value and therefore the media stream is not
set up correctly.
All the PGWs involved in the signalling all agree on one IP address and port number so it is only
the SBC that is incorrect. MGCP at the media gateway shows the correct IP and port.
Customer IP Phone (SIP or SCCP) --> CUBE (SIP) --> MPLS WAN --> ACE SBC (SIP) --> PGW (EISUP) -->
PGW (EISUP) --> PGW (ISUP IP protocols) --> SLT
Cust IP Phone --> CUBE --> ACE SBC --> MGX VXSM --> PSTN
ACE SBC Output
No media timeout remaining: 221 s
Reserved Bandwidth: 9828 (bytes/second)
Status: In Service
VRF Name: XXX-core-context01
Local Address: 10.16.248.65
Local Port: 16752
Remote Address: 18.104.22.168
Remote Port: 26966
RTP Packets Received: 18646
RTP Packets Sent: 19197
RTP Packets Discarded: 0
RTP Data Received: 5220880 (bytes)
RTP Data Sent: 5375160 (bytes)
The main question is has anyone seen this before?
Software/Hardware used: Cisco PGW Softswitch Version:9.7(3) CSCOgs026/CSCOnn026 & ACE SBC loader: Version 12.2 system: Version 3.0(1)AS31(2)
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