[Users] UA behind NAT puts public IP in Contact, Via - help

[Bogdan-Andrei Iancu]

Arek Bekiersz wrote:

> Hello Bogdan,
>
> Bogdan-Andrei Iancu wrote:
>
>> they may happen because the phone is using STUN or because of a 
>> SIP-aware router (on NAT border)
>
>
> There is no STUN and the NAT is really simple one (not SIP-aware).
>
as the trace shows, the phone does via SIP a kind of auto-detection of 
the external IP based on received and rport via params.... can you 
disable this feature?

regards,
bogdan

>
>
>
>> take a look at:
>> http://openser.org/docs/modules/1.0.x/nathelper.html#AEN349
>> you have 5 tests to detect NATed clients
>
>
> None of those tests works:
> 1) "Contact" has public IP
> 2) Via contains the same address as it was received from
> 4) Topmost Via has public IP
> 8) SDP contains public IPs (UA puts them)
> 16) Source port is the same as in Via
>
>
>
>
> This UA is a popular one. This effect is observed in firmwares that 
> are officially on the market for more than 3 months. I would like to 
> force vendor to correct this problem as soon as possible, because 
> other of us can experience similar problem. But first I want to be 
> sure this is vendor problem, not SER problem.
>
>
>
>
>
> Here is sample debug of REGISTER sequence:
> UA has IP 192.168.1.200 in private LAN behind NAT.
> NAT maps UAs port 5060 in LAN to port 61003 in WAN:
>
> 192.168.1.200:5060 -> proxy_wan_ip:5060
> REGISTER sip:proxy_realm SIP/2.0
> Via: SIP/2.0/UDP 
> 192.168.1.200:5060;branch=z9hG4bKD87C4E6B9057BD25A6EC854BAEB4F
> From: <sip:1234 at proxy_realm>;tag=2789838218
> To: <sip:1234 at proxy_realm>
> Call-ID: foo
> CSeq: 1 REGISTER
> Max-Forwards: 70
> User-Agent: stupid-user-agent
> Supported: 100rel, replaces
> Allow-Events: telephone-event, refer
> Allow: INVITE, ACK, OPTIONS, CANCEL, BYE, UPDATE, PRACK, INFO, 
> SUBSCRIBE, NOTIFY, REFER, MESSAGE
> Accept: application/sdp, multipart/mixed
> Accept-Encoding: identity
> Content-Length: 0
>
>
> proxy_wan_ip:5060 -> 192.168.1.200:5060
> SIP/2.0 401 Unauthorized
> Via: SIP/2.0/UDP 
> 192.168.1.200:5060;branch=z9hG4bKD87C4E6B9057BD25A6EC854BAEB4F;rport=61003;received=nat_wan_ip 
>
> From: <sip:1234 at proxy_realm>;tag=2789838218
> To: <sip:1234 at proxy_realm>;tag=935ab969d5b642f019e17a3a52b4e4b2.8ec3
> Call-ID: 31888733A35E0EFE3FC22B073B50C at 192.168.1.200
> CSeq: 1 REGISTER
> WWW-Authenticate: Digest realm="proxy_realm", 
> nonce="4405aadab124f8b271a6d6282a0fd9abc4b09b8e"
> Server: Sip EXpress router
> Content-Length: 0
>
>
> 192.168.1.200:5060 -> proxy_wan_ip:5060
> REGISTER sip:proxy_realm SIP/2.0
> Via: SIP/2.0/UDP 
> nat_wan_ip:61003;branch=z9hG4bK7BB67339C326394708852DEC41F3C
> From: <sip:1234 at proxy_realm>;tag=2789838218
> To: <sip:1234 at proxy_realm>
> Call-ID: foo
> CSeq: 2 REGISTER
> Authorization: Digest username="1234", realm="proxy_realm", 
> nonce="4405aadab124f8b271a6d6282a0fd9abc4b09b8e", 
> uri="sip:proxy_realm", response="5a5c8fd5e58aa3cdcaff214c5ae4d2aa"
> Max-Forwards: 70
> User-Agent: stupid-user-agent
> Supported: 100rel, replaces
> Allow-Events: telephone-event, refer
> Allow: INVITE, ACK, OPTIONS, CANCEL, BYE, UPDATE, PRACK, INFO, 
> SUBSCRIBE, NOTIFY, REFER, MESSAGE
> Accept: application/sdp, multipart/mixed
> Accept-Encoding: identity
> Content-Length: 0
>
>
> proxy_wan_ip:5060 -> 192.168.1.200:5060
> SIP/2.0 200 OK
> Via: SIP/2.0/UDP 
> nat_wan_ip:61003;branch=z9hG4bK7BB67339C326394708852DEC41F3C
> From: <sip:1234 at proxy_realm>;tag=2789838218
> To: <sip:1234 at proxy_realm>;tag=935ab969d5b642f019e17a3a52b4e4b2.1a9c
> Call-ID: foo
> CSeq: 2 REGISTER
> Server: Sip EXpress router
> Content-Length: 0
>
>
> 192.168.1.200:5060 -> proxy_wan_ip:5060
> REGISTER sip:proxy_realm SIP/2.0
> [WRONG!!] Via: SIP/2.0/udp 
> nat_wan_ip:61003;branch=z9hG4bK82B006EB79CB30C39996A78C9962D
> From: <sip:1234 at proxy_realm>;tag=2789838218
> To: <sip:1234 at proxy_realm>
> Call-ID: foo
> CSeq: 3 REGISTER
> [WRONG!!] Contact: 
> <sip:1234 at nat_wan_ip:61003;uniq=0FC6DA2B97704905AA040333C2B03>
> Authorization: Digest username="1234", realm="proxy_realm", 
> nonce="4405aadab124f8b271a6d6282a0fd9abc4b09b8e", 
> uri="sip:proxy_realm", response="5a5c8fd5e58aa3cdcaff214c5ae4d2aa"
> Expires: 1800
> Max-Forwards: 70
> User-Agent: stupid-user-agent
> Supported: 100rel, replaces
> Allow-Events: telephone-event, refer
> Allow: INVITE, ACK, OPTIONS, CANCEL, BYE, UPDATE, PRACK, INFO, 
> SUBSCRIBE, NOTIFY, REFER, MESSAGE
> Accept: application/sdp, multipart/mixed
> Accept-Encoding: identity
> Content-Length: 0
>
>
> proxy_wan_ip:5060 -> 192.168.1.200:5060
> SIP/2.0 200 OK
> Via: SIP/2.0/udp 
> nat_wan_ip:61003;branch=z9hG4bK82B006EB79CB30C39996A78C9962D
> From: <sip:1234 at proxy_realm>;tag=2789838218
> To: <sip:1234 at proxy_realm>;tag=935ab969d5b642f019e17a3a52b4e4b2.3770
> Call-ID: 31888733A35E0EFE3FC22B073B50C at 192.168.1.200
> CSeq: 3 REGISTER
> Server: Sip EXpress router
> Content-Length: 0
>
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