SG-1100 changing ports on NAT

  • We are having an issue with an SG-1100 that has a VoIP PBX behind it. Everything is fine except when there is a call to a call group. For information, all the users are remote and the PBX is located in a data center behind this firewall - the issue results in "no audio" in either direction until the user places the call on hold, then picks it back up.

    We ran a packet capture on the WAN side when this was happening. The PBX changes RTP ports as soon as the call is established. For some reason after the port change the SG1100 is changing the source port on the outbound RTP packets. It doesn't do this to any other calls even though they are using the same port range.

    The PCAP is too large to upload here, it's less than 2mg but too large.

    Any thoughts on how to correct this issue?

  • Banned

  • @Grimson thanks, appreciate it and the reminder to read the manual :-), this is a totally new product for us, so I appreciate it. I'll make these changes and do some testing.

  • @Grimson - I implemented these settings over the weekend [24/7 operation] and this clearly corrected the audio problem with the SIP trunks! THANK YOU