System:

MYIP - IP of kamailio

sip.mydomain.com - address of kamailio

User (Imsdroid for Android) ->Kamailio->Asterisk->Kamailio (same) ->Other user.

Problem - register, voice, video, and ring are OK, but ACK and BYE are going in dead loop - and this happens may be around in 50% of cases - not in all cases.

If I am using other client (like hardware SIP phones), then I have no problems, but it is really hard to find some client for Android which supports video with Kamailio.

To solve problem, I made one function in Kamailio.cfg - ACKBYE, which is called only within dialog. And within dialog is called in main route.

route[ACKBYE] {

#!ifdef WITH_MYFORWARD

xlog("SCRIPT: AckBye $td;$si;$du;$dd\n");

if((($td=="sip.mydomain.com")||($td=="MYIP"))&&($si=="MYIP")){

$du=$sht(forw=>$ft);

xlog("SCRIPT: AckBye2 $td;$si;$du\n");

return;

}

#!endif

return;

}

Of cource I have

if(is_method("INVITE")){

ds_select_dst("1","4");

$sht(forw=>$ft)=$du;

}

This worked for long time. But then we updated client (libraries etc), and problem appeared again - from time to time. Calls between 2 same clients can pass 2 or 5 times, and then problem appear.

Before - $td and $si showed destination and source but now there is difference:

ERROR: <script>: SCRIPT: AckBye 192.168.2.251;MYIP;<null>;<null>

$td in this case show destination, which is correct, but in wireshark, destination and source = MYIP.

ACK sip:MYIP;lr=on;nat=yes SIP/2.0

Via: SIP/2.0/UDP MYIP;branch=z9hG4bKcydzigwkX

Via: SIP/2.0/UDP MYIP;rport=5060;branch=z9hG4bKcydzigwkX

............................................

Via: SIP/2.0/UDP MYIP;rport=5060;branch=z9hG4bKcydzigwkX

Via: SIP/2.0/UDP 192.168.2.105:44794;branch=z9hG4bK338581244;rport=44794

From: <sip:11171@sip.MYDOMAIN.com>;tag=1687441663

To: <sip:11175@192.168.2.251>;tag=as13c57096

Contact: <sip:11171@MYIP:5060;transport=udp>;+g.oma.sip-im;language="en,fr";+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"

Call-ID: 4026cd88-aab9-19db-dfbe-1510baafdbb3

CSeq: 473985105 ACK

Content-Length: 0

Max-Forwards: 0

Proxy-Authorization: Digest username="11171",realm="sip.stribogkonsult.com",nonce="T2NZUU9jWCWxMUHSQweHXVQppHS8iFhd",uri="sip:11175@MYIP:5060",response="c5a95942af1502c208fa05d34c405907",algorithm=MD5

Accept-Contact: *;+g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"

P-Preferred-Service: urn:urn-7:3gpp-service.ims.icsi.mmtel

Allow: INVITE, ACK, CANCEL, BYE, MESSAGE, OPTIONS, NOTIFY, PRACK, UPDATE, REFER

Privacy: none

P-Access-Network-Info: ADSL;utran-cell-id-3gpp=00000000

User-Agent: IM-client/OMA1.0 android-ngn-stack/v2.0.453 (doubango r653)