Any Issues If SIP proxy uses different source/dest ports?

[Spoke]

1. Brekeke Product Name and version:

SIP 2.0

2. Java version:

J2SE Runtime environment 5.0 update 11

3. OS type and the version:

XP Pro Version 2002; SP1

4. UA (phone), gateway or other hardware/software involved:

Assorted SIP phones: D-Link, LG-Nortel.
Private network: proprietary hardware and SIP proxy software

5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/networkpatterns.html :

Pattern 7; SIP proxy in private network is proprietary s/w; Brekeke SIP server is on the enterprise side. NAT is enabled on the private network.

6. Your problem:

For enterprise phone to private network phone call, handshaking between SIP proxy and Brekeke mostly ok. Enterprise phone sends INVITE to Brekeke who forward it to SIP proxy who forwards it to the callee phone. When private network callee phone goes off-hook and sends 200OK w/Session Description message to SIP proxy, proxy forwards 200OK to Brekeke but Brekeke doesn't forward to enterprise (calling) phone and call not established.

We notice that proprietary proxy transmits on port 6001 (after NAT translation) but listens on port 5060. Any issue that Brekeke would not forward 200OK to calling phone if it recieves 200OK from port 6001 instead of 5060 since Brekeke sent the INVITE to sip proxy at 5060?

Thanks,
Jerry
l

[voipwell.com]

Hi,

I don't think Brekeke can receive on both 5060 and 6001 so if brekeke is behind a nat you can try to use a port trigger to change the 6001 packets to 5060.

Nick

[Spoke]

Hi Nick,

Thank you for the response. The packets from my SIP proxy to Brekeke have destination port 5060 as needed for Brekeke to receive properly. My question is whether Brekeke has issues if my SIP proxy sends packets with souce port of 6001 when my SIP proxy receives packets on 5060.

Does my SIP proxy sending/listening on 6001/5060 cause any issues for Brekeke?

Thanks,
Jerry

[voipwell.com]

Oh, I see.

Brekeke shoudn't have a problem with the source port since many ata's and ip phones use alternate ports after going thru a nat. I'm not sure what is causing your problem.

Nick