PJSIP Transports: Dual UDP, different ports

We’re migrating from port 5060 to a more obscure port.

I’ve setup two transports, default-udp-transport that uses 5060 and alternate-udp-transport that uses the new port.

For testing, I’ve blocked via ipatables any udp inbound connections via 5060.

Seems to be working great, but I’m seeing something confusing I’d like to run by the community.

I have a Polycom phone to which the port is correctly set to the new port using alternate-udp-transport but the registered contact shows it’s using 5060. To reiterate, 5060 is blocked and I’ve confirmed that with a scanning tool.

Any idea why port 5060 would be shown in the contact?


Thanks for any insight!

Because that is the location of the contact. Which means Asterisk will send requests to x.x.x.x:5060.

Thanks for the reply, Blaze.

5060 isn’t in use anywhere, the registration is coming from the alternate port.

Are you saying it’s because my firewall is opening 5060 outbound for the NAT port? So it’s connecting “to” the alternate port on the Asterisk side but “from” 5060?

Doesn’t seem to be the case, the NAT table has just a random port. The SIP packets don’t reflect 5060. Confused.

No. I am saying that you have Asterisk listening on a specific port, which the phones needs to register/send calls to. The phone itself is listening on 5060. The address in the contact is the client side ie their ip and port.

Yep, understand that. Just not seeing it in the NAT table. Digging in, thanks for the help!

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.