[asterisk-users] Reinvite / one-way media.

[Alex Balashov]

I have two phones on a network behind NAT.  Enabling canreinvite=yes on 
the Asterisk server allows them to talk to each other very effectively
through the local network.

Unfortunately, calling any outside destinations yields one-way media
issues where the far end can hear me but I can't hear them, probably
due to lack of an ALG on the NAT router that understands the SDP
negotiation of the RTP ports.

I like reinvites in theory--it leads to far more efficient and low-latency
interaction with my outside termination providers by saving at least one
round trip up and down the coast, which is the result of where the 
Asterisk server is in relation to the phones and the termination provider.

What can I do?

I suppose one approach is to hard-pin and forward the RTP ports both
phones negotiate to;  both phones have that capability.  Then I can
forward them (DNAT) on the gateway.

Anything easier or rather obvious I'm missing?

Thanks!

--
Alex Balashov
Evariste Systems
Web    : http://www.evaristesys.com/
Tel    : +1-678-954-0670
Direct : +1-678-954-0671