[OpenSIPS-Users] SUBSCRIBE & NOTIFY - NAT Problems

Samuel Anderson sanderson at ArnoldMagnetics.com
Thu Jun 25 21:29:08 EST 2020

Hi Everyone,

I use OpenSIPS as an SBC for an Asterisk server. The OpenSIPS server is multi-homed and has an interface on the WAN and DMZ. I'm able to make calls and send sequential requests in a dialog, such as INVITEs and BYEs, from endpoints behind NAT without any issues. My problem is when the endpoints try to  SUBSCRIBE, and Asterisk sends a NOTIFY message back. OpenSIPS is sending the NOTIFY to the original contact header specified in the SUBSCRIBE request. It is not sending the NOTIFY to the address it received it from. It does rewrite the contact header when the SUBSCRIBE message is sent to Asterisk, and OpenSIPS also sends the 200 OK reply to the correct address.

How can I configure OpenSIPS to send the additional NOTIFY messages within the dialog to the address it received it from? I've tried to create a dialog for SUBSCRIBE requests, but it looks like that only works for INVITEs. Any help would be appreciated. It currently works fine with INVITEs and BYEs.

I use double record routes, topology hiding, and the dialog module. I also set "fix_nated_contact" when the SUBSCRIBE is received.

Thank you for your assistance.


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