Selective inbound port nat based on source ip

[scheidell]

I have a situation on a SIP product that insists on splitting up the sip traffic.
port 5060 if for phones, port 5080 is for SIP trunks. (I think they do it to get around needing a separate ip/box for the SBC)

What I would like to do is take everything from the SIP trunk provider that hits port 5060 and fwd it internally to port 5080.
(easy enough with proxy arp, and port forwarding).

BUT, I want everything the works sends to that same port 5060 to go to port 5060 internally.

I tried this:
Firewall rules:
inbound:
allow siptrunk to sipprivate:5080
allow any to sipprivate:5060
Two port forward nat rules.

nat external port 5060 to sipprivate:5080
nat external port 5060 to sipprivate:5060

(just describing it shows me it shouldn't work)

[danswartz]

what does 'the works' mean?

[Efonnes]

This was added in 2.0, which is currently in beta.