[Serusers] problems with stun using uas

[lorenzo]

hi!

i'm the developer of a sip app that happens to be connecting to a sip
server that's using SER.

i'm having troublewith the way SER handles incoming calls to my
stun-enabled ua (which is placed behind a router)

I have two clients running on the same machine. one is my app, the other
is Gizmo5.

when i make an outgoing call from my app to the user i'm logged in with
in Gizmo5, everything works.

but when i call my app from the Gizmo5 app,  sniffing the network
traffic with wireshark, the only thing i see happening is the sip server
sending a 100 Giving a try to the calling ua.

The reason i'm posting this here, is that i know it's not a bug with my
app, since everything works fine when i don't use stun.

(note that i don't have direct access to ser's configuration)

this is my app's REGISTER request (note that it has a *public ip*):

REGISTER sip:proxy01.sipphone.com SIP/2.0
Via: SIP/2.0/UDP 93.148.135.54:5060;rport;branch=z9hG4bK70207
Max-Forwards: 70
To: <sip:asymmetric at proxy01.sipphone.com>
From: <sip:asymmetric at proxy01.sipphone.com>;tag=z9hG4bK57274073
Call-ID: 557402852938 at 93.148.135.54
CSeq: 2 REGISTER
Contact: <sip:asymmetric at 93.148.135.54:5060;transport=udp>
Expires: 3600
User-Agent: mjsip stack 1.6
Authorization: Digest username="asymmetric",
realm="proxy01.sipphone.com", nonce="xxx",
uri="sip:proxy01.sipphone.com", algorithm=md5, response="yyy"
Content-Length: 0

and the response:

SIP/2.0 200 OK
Via: SIP/2.0/UDP 93.148.135.54:5060;rport=12810;branch=z9hG4bK70207
To:
<sip:asymmetric at proxy01.sipphone.com>;tag=92390300a369f0d75803e369c733575e.50aa
From: <sip:asymmetric at proxy01.sipphone.com>;tag=z9hG4bK57274073
Call-ID: 557402852938 at 93.148.135.54
CSeq: 2 REGISTER
Contact: <sip:asymmetric at 93.148.135.54:5060;transport=udp>;expires=3600
Content-Length: 0

Gizmo5's app REGISTER request:

REGISTER sip:proxy01.sipphone.com SIP/2.0
Via: SIP/2.0/UDP
192.168.1.100:64064;branch=z9hG4bK-d87543-bbc1e2712d417352-1--d87543-;rport
Max-Forwards: 70
Contact: <sip:17474492586 at 93.148.135.54:10251>
To: <sip:17474492586 at proxy01.sipphone.com>
From: <sip:17474492586 at proxy01.sipphone.com>;tag=f43be43c
Call-ID: b1b4a060512d4b0c1250955005 at YXN5bW1ldHJpYy5sb2NhbA..
CSeq: 2 REGISTER
Expires: 1800
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER
User-Agent: MacGizmo/2.0.02 (Gizmo-s2n1)
Authorization: Digest
username="17474492586",realm="proxy01.sipphone.com",nonce="xxx",uri="sip:proxy01.sipphone.com",response="yyy",algorithm=MD5
Content-Length: 0

and response:

SIP/2.0 200 OK
Via: SIP/2.0/UDP
192.168.1.100:64064;branch=z9hG4bK-d87543-bbc1e2712d417352-1--d87543-;rport=10251;received=93.148.135.54
To:
<sip:17474492586 at proxy01.sipphone.com>;tag=92390300a369f0d75803e369c733575e.c70f
From: <sip:17474492586 at proxy01.sipphone.com>;tag=f43be43c
Call-ID: b1b4a060512d4b0c1250955005 at YXN5bW1ldHJpYy5sb2NhbA..
CSeq: 2 REGISTER
P-Behind-NAT: Yes
Contact: <sip:17474492586 at 93.148.135.54:10251>;expires=1800
Content-Length: 0

in the second case, the client gets the P-Behind-NAT flag set to Yes,
and for a good reason.

But then why is this all i get when trying to call the first ua? :

SIP/2.0 100 Giving a try
Via: SIP/2.0/UDP
192.168.1.100:64064;branch=z9hG4bK-d87543-7fb07a028db5c137-1--d87543-;rport=10251;received=93.148.135.54
To: <sip:asymmetric at proxy01.sipphone.com>
From: <sip:17474492586 at proxy01.sipphone.com>;tag=bc135372
Call-ID: 88d41c746d51146e1250955219 at YXN5bW1ldHJpYy5sb2NhbA..
CSeq: 1 INVITE
P-Behind-NAT: Yes
Content-Length: 0

whereas the inverse works:

SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 198.65.166.131;branch=z9hG4bKf3b1.bc014575.0
Via: SIP/2.0/UDP 93.148.135.54:5060;rport=13171;branch=z9hG4bK82654
Record-Route: <sip:198.65.166.131;lr;ftag=z9hG4bK90319798>
Contact: <sip:17474492586 at proxy01.sipphone.com>
To: <sip:17474492586 at proxy01.sipphone.com>;tag=6ae0e759
From: "asymmetric"<sip:asymmetric at proxy01.sipphone.com>;tag=z9hG4bK90319798
Call-ID: 593542951976 at 93.148.135.54
CSeq: 1 INVITE
User-Agent: MacGizmo/2.0.02 (Gizmo-s2n1)
Content-Length: 0
CQBM: 244

-- 
thanks a lot!
asymmetric