Hello,

it looks like you have a symmetric nat router, so the allocated port is randomly selected.

If you don't control the nat router to set a static forwarding rule or it doesn't provide the option to set static forwarding, then you are pretty much left with sniffing the traffic to discover the external port and advertise it.

Cheers,
Daniel



On 13/01/16 20:31, Nelson Migliaro wrote:
Hello,

I finally were able to run my Kamailio behind NAT but in order to accomplish that I included:

listen=udp:SOURCE-IP:5060 advertise PUBLIC-IP:52548

52548 is the port my internet router change when doing NAT (5060->52548). I found this port sniffing traffic

Conclusions at this point are:

---------------------------------------------1--------------------------------------------------------------------------------------------------
If I use this line:

listen=udp:SOURCE-IP:5060 advertise PUBLIC-IP:5060 it does not work :(

When I dial a call, INVITE / ACK / Trying / OK goes fine because they are part of the same transaction
When remote party disconnects the call, BYE goes to PUBLIC-IP port 5060 and router blocks de request. I assume vendor sends BYE to 5060 because it is a new transaction

-----------------------------------------------2--------------------------------------------------------------------------------------------------
If I use this line:

listen=udp:SOURCE-IP:5060 advertise PUBLIC-IP:52548 it work !!!!!!

When I dial a call, INVITE / ACK / Trying / OK goes fine because they are part of the same transaction
When remote party disconnects the call, BYE goes to PUBLIC-IP port 52548 and router forward the request to Kamailio. Since there is an open connection.

I need to find the way to find the way to advertise the public port internet router is doing NAT (PAT).

---------------------------------------------------------------------------------------------------------------------------------------------------
This trace is a call that worked fine because I included line:

listen=udp:SOURCE-IP:5060 advertise PUBLIC-IP:52548


This trace is an INVITE with this line: listen=udp:SOURCE-IP:5060 advertise PUBLIC-IP:52548
2016/01/13 20:10:15.793568 PRIVATE-IP-KAMAILIO:5060 -> VENDOR-IP:5060
INVITE sip:NUM-DESTINATION@VENDOR-IP SIP/2.0
Record-Route: <sip:PUBLIC-IP:52548;lr=on;ftag=as3b72a453;vsf=AAAAAAEECQkCAgsNAXBeL0NPXVQfU0suMTY5LjIzMQ--;vst=AAAAAAAAAAAAAAAAAABCUEIAX1lKWF5MF0tB
A-;nat=yes>
Via: SIP/2.0/UDP PUBLIC-IP:52548;branch=z9hG4bKdd74.992e238037882e809653f713a5a580a9.0
Via: SIP/2.0/UDP PRIVATE-IP-SOFTPHONE:5060;received=PRIVATE-IP-SOFTPHONE;branch=z9hG4bK2f4e76ba;rport=5060
Max-Forwards: 69
From: NUM-SOURCE <sip:NUM-SOURCE@PRIVATE-IP-KAMAILIO>;tag=as3b72a453
To: <sip:NUM-DESTINATION@sip.VENDOR-IP>
Contact: <sip:NUM-SOURCE@PRIVATE-IP-SOFTPHONE:5060;alias=PUBLIC-IP~5060~1>
Call-ID: 329950447629810f7bdeaeed0cc034e1@PRIVATE-IP-SOFTPHONE:5060
CSeq: 102 INVITE
User-Agent: Kamailio
Date: Wed, 13 Jan 2016 19:10:15 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, PUBLISH, MESSAGE
Supported: replaces, timer
Content-Type: application/sdp
Content-Length: 255


Trying.....

2016/01/13 20:10:15.842055 VENDOR-IP:5060 -> PRIVATE-IP-KAMAILIO:5060
SIP/2.0 100 trying -- your call is important to us
Via: SIP/2.0/UDP PUBLIC-IP:52548;branch=z9hG4bKdd74.992e238037882e809653f713a5a580a9.1;rport=52548
Via: SIP/2.0/UDP PRIVATE-IP-SOFTPHONE:5060;received=PRIVATE-IP-SOFTPHONE;branch=z9hG4bK2f4e76ba;rport=5060
From: NUM-SOURCE <sip:NUM-SOURCE@PRIVATE-IP-KAMAILIO>;tag=as3b72a453
To: <sip:NUM-DESTINATION@VENDOR-IP>
Call-ID: 329950447629810f7bdeaeed0cc034e1@PRIVATE-IP-SOFTPHONE:5060
CSeq: 102 INVITE
Server: kamailio
Content-Length: 0




And finally a BYE

2016/01/13 20:10:28.545526 VENDOR-IP:5060 -> PRIVATE-IP-KAMAILIO:5060
BYE sip:34982298000@PRIVATE-IP-SOFTPHONE:5060;alias=PUBLIC-IP~5060~1 SIP/2.0
Via: SIP/2.0/UDP VENDOR-IP;branch=z9hG4bK26d8.847e6e14eef37e2cfc8b5e81d33de73d.0
From: <sip:675896262@PRIVATE-IP-KAMAILIO>;tag=gK0293ed93
To: "NUM-SOURCE" <sip:NUM-SOURCE@norvoz.es>;tag=as3b72a453
Call-ID: 329950447629810f7bdeaeed0cc034e1@PRIVATE-IP-SOFTPHONE:5060
CSeq: 28731 BYE
Max-Forwards: 69
Route: <sip:PUBLIC-IP:52548;lr=on;ftag=as3b72a453;vsf=AAAAAAEECQkCAgsNAXBeL0NPXVQfU0suMTY5LjIzMQ--;vst=AAAAAAAAAAAAAAAAAABCUEIAX1lKWF5MF0tBMzA-;na
yes>
Reason: Q.850;cause=16
Content-Length: 0



-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------

Finally, It is finally working because I hardcoded NATīd port.
I would like to find a way to avoid setting the port in "hard".

Thank you





-- 
Daniel-Constantin Mierla
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Book: SIP Routing With Kamailio - http://www.asipto.com
http://miconda.eu