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2 Replies Last post: Mar 1, 2010 11:36 PM by maxglucksmann  
Click to view maxglucksmann's profile   4 posts since
Mar 1, 2010

Mar 1, 2010 10:10 PM

ACK TIMEOUT - No response to OpenSBC from Asterisk


Good evening,


We're trying to use OpenSBC to proxy calls from an Asterisk server.

Our OpenSBC is registering with a SIP trunk and our Asterisk server registers in OpenSBC. We're not using Upper Registration.

When sending calls, the call is forwarded to the SIP trunk accordingly, but once the call is connected and OpenSBC sends the CSeq message 102 to the INVITE with a 200 OK, for some reason Asterisk doesn't send back an ACK message and OpenSBC hungs up giving a ACK TIMEOUT error.


This is one of the 200 OK messages in Asterisk's console:

pbx1*CLI>
<--- SIP read from xxx.xxx.xxx.xxx:5060 --->
SIP/2.0 200 OK
From: "5555558888" <sip:5555555555@yyy.yyy.yyy.yyy>;tag=as1b56c719
To: <sip:555666777777@xxx.xxx.xxx.xxx>;tag=5ae8224f1424df11955bb1dafd175bf5
Via: SIP/2.0/UDP yyy.yyy.yyy.yyy:5060;branch=z9hG4bK18a69deb;rport=5060;received=yyy.yyy.yyy.yyy
CSeq: 102 INVITE
Call-ID: 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
Contact: <sip:555666777777@xxx.xxx.xxx.xxx:5060>
Record-Route: <sip:xxx.xxx.xxx.xxx:5060;lr>
Server: SIP Trunk
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
Content-Type: application/sdp
Content-Length: 289

v=0
o=root 25214 25215 IN IP4 xxx.xxx.xxx.xxx
s=session
c=IN IP4 xxx.xxx.xxx.xxx
b=CT:384
t=0 0
m=audio 10016 RTP/AVP 0
a=rtpmap:0 PCMU/8000
a=silenceSupp:off - - - -
a=ptime:20
a=sendrecv
m=video 10018 RTP/AVP 31 34
a=rtpmap:31 H261/90000
a=rtpmap:34 H263/90000
a=sendrecv

<------------->

No response is sent by Astyerisk. Meanwhile, the log of OpenSBC looks like this:

      • CALL ESTABLISHED ***
ACK sip:19543666429@xxx.xxx.xxx.xxx:5064 SIP/2.0 Method(ACK) DST: xxx.xxx.xxx.xxx:5064:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=483
<<< ACK sip:19543666429@xxx.xxx.xxx.xxx:5064 SIP/2.0 Method(ACK) SRC: xxx.xxx.xxx.xxx:5060:UDP enc=0 bytes=483
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP src=xxx.xxx.xxx.xxx:5061 enc=0 bytes=917
200 Ok - 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=907
200 Ok - 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=907
200 Ok - 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=907
RETRANSMIT: 200 Ok - 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=907
RETRANSMIT: 200 Ok - 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=907
RETRANSMIT: 200 Ok - 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy
SIP/2.0 200 OK Method(INVITE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=907
! ACK Timeout !
      • B2BUACONNECTION DESTRUCTION SEQUENCE STARTED
      • CALL TEAR DOWN *** 4690dbc52e0f43d86e2396be1cd1f5f4@yyy.yyy.yyy.yyy-connection
BYE sip:5555558888@yyy.yyy.yyy.yyy SIP/2.0 Method(BYE) DST: yyy.yyy.yyy.yyy:5060:UDP SRC: xxx.xxx.xxx.xxx:5060 enc=0 bytes=487

Any guidance will be greatly appreciated.


Thanks,

Max Glucksmann

Comtel Networks

Click to view joegen's profile   519 posts since
Apr 28, 2007
1. Mar 1, 2010 11:20 PM in response to: maxglucksmann
Re: ACK TIMEOUT - No response to OpenSBC from Asterisk
I don't want to sound annoying but have you tried asking this question to the asterisk mailing list? The key in solving this is to pinpoint what causes asterisk to ignore the 200 OK. As far as I can tell, it's perfectly constructed.