siproxd zyxel2000W problems

hi!

I got a Zyxel Prestige 2000W WLAN VOIP phone here that I am trying to get
to work with a sipgate account. Now the phones firmware is pretty primitive
with not much configuration options, and it did not work with the local
network setup, so I installed siproxd 0.5.9 (now the 0.5.10 snapshot as of
January 10th).
I am able to make calls to other softphones in the local net, but connections
to or from the outside fail with the following symptoms:

1. STUN ENABLED

-ringing the external phone works, ringing in from the external phone works,
  but audio does not work in either direction

2. STUN DISABLED

-ringing in works, with external audio source arriving, but the VOIP phones
audio source remains mute.
-ringing out to the landline phone gives an error message playback
  from sipgate
-calling sipgate's 10000 test number connects to the welcome message.

The network setup looks like this:

gateway:

Fedora Linux Box with kernel 2.6.7 and iptables NAT/firewall, 
ports 5060, 5061, 10000 and 7070:7079 open.
Q-DSL internet connection

local network: Netgear ME102 WLAN router

There also is an independent Asterisk installation on the gateway, so I use 
port 5061 for the outgoing proxy, but changing that to 5060 does not make 
any difference.

I am not too sure where to look for problems there. There are absolutely no
log messages from the phone itself, and I bet there are lots of bugs in
the firmware, but since local sip calls work I guess there must
be something going wrong with the RTP relaying. There is no restriction
on outgoing packets, so I do not think it is a firewall problem.

... and now I am totally confused because calls in the local network
do not work any more with the same configuration I tried last time...

Does anybody have any experience with the Zyxel phone? Or any suggestions
as how to pinpoint the problem?

-- 
peter koellner <[email protected]>


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