Sip handshake / media different IPs

The VOIP provider I am testing sends SIP handshake (PORT 5060) using a separate IP address from their MEDIA (UDP).

I cant find any obvious references in, so I am hoping someone here has any advice on how to configure the context. Does anyone have advise?

-Erich Stein

Both are UDP.

You tell them the address to which to send media.

If you meant the address to which you should send media, that is sent in the SIP protocol payload and you should not need to do anything to meet this requirement.

I can only send and receive media from only 1 public IP address.

After studying the traffic from my firewall after configuring dNAT, I found I was dropping lots of incoming packets when placing my outbound calls on an IP address I didn’t recognize. I brought it to the attention of the vendor’s tech-support. Their response was that they send the handshaking and media over separate IP addresses.

The calls DO land, and I get two-way audio. Ideally I would like the configuration to be tidy, so if my customer decides to scale up the service - this dropped traffic does not present problems.

-Erich Stein

The IP address they use for control and media should not affect you at all, unless you have firewall rules that block one of them. When talking to you, they should use your public address, or more precisely, they should use the addresses that are in the SIP packets that they send.