[OpenSIPS-Users] B2BUA Transfers Intermittently Working/Not Working (Bug?)

[Brett Woollum]

Anca, 

I've discovered that the REFER messages sent from the phones to the OpenSIPS server/B2BUA are not receiving a 202 Accepted reply from the B2BUA module, and as a result, the phones continue to re-send the REFER's. The B2BUA module doesn't recognize the additional REFER's because it has already torn down the original call leg. As a result the additional REFER's are processed in the route script which is wrong and causes the 404 Not Found errors. 

Here is what's happening: (assume a call already exists): 
The phone sends a REFER to the B2BUA 
The B2BUA sends BYE back to the phone 
The B2BUA invites the new leg of the call to the other phone 
The original phone continues to send REFER's to the B2BUA module, which responds with 404 Not Found's 

I believe there should be a 202 Accepted sent from the B2BUA module to the phone in response to the first REFER message, not a BYE (or maybe both Accepted and BYE). But there is no 202 Accepted coming from the B2BUA module to the phone. 

Scroll to the bottom of http://www.woollum.com/temp/opensips.txt to view my B2BUA XML config, which specifies that the B2BUA should respond with a 202 Accepted before ending the call leg. This is not happening like it should.... 

I am running OpenSIPS 1.6.3 on CentOS 5.5 x64 (on an AMD platform). 


Brett Woollum 
Brett at Woollum.com 


----- Original Message ----- 
From: "Anca Vamanu" <anca at opensips.org> 
To: users at lists.opensips.org 
Sent: Tuesday, October 19, 2010 2:20:15 AM GMT -08:00 US/Canada Pacific 
Subject: Re: [OpenSIPS-Users] B2BUA Transfers Intermittently Working/Not Working (Bug?) 

Hi Brett, 

No, you needn't add anything else in your configuration file except for the b2b_init_request for the initial Invite and the B2BUA should know to handle the REFER that comes inside that dialog. What happens is the the B2BUA does not find a matching dialog for that REFER message .. I don't know why that is. I will examine the traces you posted and try to reproduce this in the following days and let you know. 

Regards, 
-- 
Anca Vamanu www.voice-system.ro 
On 10/19/2010 09:05 AM, Brett Woollum wrote: 


Hello again Anca, 

I've done more debugging, and I've found that the REFER packets are all targeting my B2BUA address and getting a 404 response. It seems to still be working, but I'm wondering if this is what is causing the problem after the 2nd transfer. 

In my log at http://www.woollum.com/temp/opensips_trace.html , you can see the 404 Not Found's occurring at packet 9177. This one in particular is generated for the packet above it (9175) that has "sip:b2bua at 1.2.3.4" in the header of the packet. 

I've configured my B2BUA module with this entry: 
modparam("b2b_entities", "server_address", "sip:b2bua at 1.2.3.4:5060" ) 

and this is the config file that is creating the errors: 
if (uri==myself) { 

if (method=="REGISTER") { 
save("location"); 
exit; 
}; 

# native SIP destinations are handled using our USRLOC DB 
if (!lookup("location")) { 
xlog("USRLOC LOOKUP: ERROR 404 - NOT FOUND $fu->$ru"); 
sl_send_reply("404", "Not Found"); 
exit; 
}; 
append_hf("P-hint: usrloc applied\r\n"); 
}; 

And this is what is generated in the OpenSIPS log: 
Oct 18 22:56:42 sip01 /usr/local/sbin/opensips[4425]: USRLOC LOOKUP: ERROR 404 - NOT FOUND sip:1000 at 1.2.3.4 -> sip:b2bua at 1.2.3.4:5060 

Is there something I need to add to my configuration that handles packets with "b2bua at 1.2.3.4" as the destination ($ru)? 


Brett Woollum 
Brett at Woollum.com 


----- Original Message ----- 
From: "Brett Woollum" <brett at woollum.com> 
To: "OpenSIPS users mailling list" <users at lists.opensips.org> 
Sent: Monday, October 18, 2010 5:09:34 PM GMT -08:00 US/Canada Pacific 
Subject: Re: [OpenSIPS-Users] B2BUA Transfers Intermittently Working/Not Working (Bug?) 


Hi Anca, 

I set debug=6 but it does not appear to print any more detailed information to my log (/var/log/messages). 

I reviewed the sip trace I posted at http://www.woollum.com/temp/opensips_trace.html and I still cannot find any packets that are missing the header. The error log I posted at http://www.woollum.com/temp/opensips.txt says that the To field, From field, and RR field could not be parsed. It seems as though the B2BUA module tried to open a new leg but didn't send the information along? Does that make sense?