Linksys SIP网关NAT问题
Hi, Guys:
I am hitting a wall here. Trying to set up a simple point-to-point Voip by following the instruction http://forum.voxilla.com/linksys-sip…oint-9415.html
My configure is cable modem->WRT54GC->SPA3102. The same to the other location. The problem is when I pick up the phone, it did ring on the other end, but no voice at all when the other end answer the phone! I’ve forward the port 5060-5080, 16384-16482 both TCP and UDP to the SPA3102 in the router configuration. The SPA is in router’s DMZ.
If I move the SPA in front of the router, then everything is fine, voice pass through no problem. So, what should I do to make it work behind the router? Any suggestion?
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The problem you describe sounds like a NAT Transversal problem. The main variables that effect NAT Transversal are
On the Line tab:
NAT Mapping Enable
NAT Keep Alive Enable
On the SIP tab
the STUN server setup
Substitute VIA Addr:YES
Send Resp To Src Port:YES
STUN Enable:YES
STUN Server:stun.softjoys.com (or any other STUN server)
NAT Mapping Enable affects the address sent in the SIP invite.
NAT Keep Alive Enable is used if you need to keep the ports open in the router.
A STUN server sends back information about the NAT and will effect how the adapter sends or responds to a Sip Invite. A STUN server does not work unless you have NAT Mapping Enable. If you are using a static address you need to specify DNS servers to enable the packets be sent to the STUN server.
You need to have the SIP signalling ports forwarded on the router to the ata because you are sending unsolicited call requests without registration. The SIP signalling ports are the port numbers that you have specified on the Line Tab (and PSTN tab if you are using that). The router may be changing port numbers without your knowledge and that is something that the STUN server will flesh out for the adapter.
There is not a set answer for configuring the ata to a router. Different router models often work differently. I would try with and without NAT Mapping Enable. Then I would add the STUN server to NAT Mapping Enable and see if I made any progress.
The best additional tool to use is the Sipura Debug Trace which will show the commands flowing back and forth.
按照作者的答复，似乎这样就搞定了。