Our company has a call center implementation on a client with up to 100 support personnel using X-Lite version 1050 softphones running under Windows 98. Until a few days ago, the softphones were logged in directly on our PBXs. Now, they log onto a separate SER 0.8.14 box and the PBXs forward calls to SER. That was needed to unify queue management. It works. But some softphones are being randomly kicked out of SER, it seems SER isn't receiving the refresh REGISTER messages from the softphones. The re-register timeout is set to 500 seconds on the softphones. There's a lot of "removing spare zombie" and "Binding '<user>','<url>' has expired" messages in /var/log/messages.

For now, we're instructing the client to increase the timeout to 10 hours on the softphones in which the problem happens most often. I don't know if that's really the right thing to do, I think we should somehow make sure the re-registers are done in a timely fashion and retried, but I could not find ant SER configuration option related to that. What should I do?

Sure... SER: REGISTER sip:xxx.xxx.xxx.xxx SIP/2.0 Via: SIP/2.0/UDP 192.168.0.4:5060;branch=z9hG4bKd9e688a70 Max-Forwards: 70 Content-Length: 0 To: 5008 <sip:18182002@xxx.xxx.xxx.xxx> From: 5008 <sip:18182002@xxx.xxx.xxx.xxx>;tag=1f55b6cd5586c2d Call-ID: 928d75b5b6c7d128a0ccaf24e5b52c74(a)192.168.0.4 CSeq: 1028949335 REGISTER Contact: 5008 <sip:18182002@192.168.0.4:5060;user=phone>;expires=60 Allow: NOTIFY Allow: REFER Allow: OPTIONS Allow: INVITE Allow: ACK Allow: CANCEL Allow: BYE User-Agent: InterEdge-ieta200 ASTERISK: REGISTER sip:xxx.xxx.xxx.xxx SIP/2.0 Via: SIP/2.0/UDP 192.168.0.4;branch=z9hG4bKf91124aeb Max-Forwards: 70 Content-Length: 0 To: 603200661 <sip:603200661@xxx.xxx.xxx.xxx> From: 603200661 <sip:603200661@xxx.xxx.xxx.xxx>;tag=7f4a78971dd573b Call-ID: 59a4ee90d5fbe74f8de459fb2506acf0(a)192.168.0.4 CSeq: 937060361 REGISTER Contact: 603200661 <sip:603200661@192.168.0.4;user=phone>;expires=1200 Allow: NOTIFY Allow: REFER Allow: OPTIONS Allow: INVITE Allow: ACK Allow: CANCEL Allow: BYE Authorization:Digest response="869ebcdfd4f83cfd805c0b03e768b9a5",username="603200661",realm="x xx" ,nonce="297966ac",uri="sip:xxx.xxx.xxx.xxx" User-Agent: InterEdge-ieta200 Regards, Chia -----Original Message----- From: 'Jan Janak' [mailto:jan@iptel.org] Sent: Thursday, June 23, 2005 5:44 PM To: Chia Huey Lim Cc: 'Juan Carlos Castro y Castro'; serusers(a)lists.iptel.org Subject: Re: [Serusers] SER losing SIP registrations Could send me also the REGISTER messages ? Jan. On 23-06-2005 17:36, Chia Huey Lim wrote: asterisk. And SER 192.168.0.4:5060;branch=z9hG4bKef17e9623;rport=32914;received=xxx.xxx.xxx .xx Contact:<sip:18182002@xxx.xxx.xxx.xxx:32914;user=phone>;expires=60;receiv ed= > "sip:xxx.xxx.xxx.xxx:32914" > Server: Sip EXpress router (0.9.0 (i386/linux)) > Content-Length: 0 > > ASTERISK: > ÄÄ > x9SIP/2.0 200 OK > Via: SIP/2.0/UDP > 192.168.0.4;branch=z9hG4bKf91124aeb;received=xxx.xxx.xxx.xxx;rport=3291 >4 From: 603200661 <sip:603200661@xxx.xxx.xxx.xxx>;tag=7f4a78971dd573b > To: 603200661 <sip:603200661@xxx.xxx.xxxx.xxx>;tag=as4f0c60fe > Call-ID: 59a4ee90d5fbe74f8de459fb2506acf0(a)xxx.xxx.xxx.xxx > CSeq: 937060361 REGISTER > User-Agent: xxx > Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER > Expires: 1200 > Contact: <sip:603200661@xxx.xxx.xxx.xxx;user=phone>;expires=1200 > Date: Wed, 22 Jun 2005 04:36:20 GMT > Content-Length: 0 > > Thanks. > > Regards, > Chia > > > -----Original Message----- > From: serusers-bounces(a)iptel.org [mailto:serusers-bounces@lists.iptel.org] On > Behalf Of Jan Janak > Sent: Thursday, June 23, 2005 4:39 PM > To: Juan Carlos Castro y Castro > Cc: serusers(a)lists.iptel.org > Subject: Re: [Serusers] SER losing SIP registrations > > On 22-06-2005 17:57, Juan Carlos Castro y Castro wrote: > > Our company has a call center implementation on a client with up to > > 100 support personnel using X-Lite version 1050 softphones running > > under Windows 98. Until a few days ago, the softphones were logged in > > directly on our PBXs. Now, they log onto a separate SER 0.8.14 box > > and the PBXs forward calls to SER. That was needed to unify queue > > management. > > > > It works. But some softphones are being randomly kicked out of SER, > > it seems SER isn't receiving the refresh REGISTER messages from the > > softphones. The re-register timeout is set to 500 seconds on the > > softphones. There's a lot of "removing spare zombie" and "Binding > > '<user>','<url>' has expired" messages in /var/log/messages. > > The message means that SER did not receive REGISTER re-fresh and is > thus removing the contact from the user location database. > > Pick one user agent that has this problem and install ngrep monitor > on the server to monitor all REGISTER messages from that user agent. > This way you could find out if the problem is in the user agent or > network (in this case you will not see REGISTER refresh messages on the > server) or in SER (in that case you will see them but SER probably > fails to process them). > > Also make sure that SER is not configured to shorten the registration > period. When registrar receives a REGISTER message, it is free to use > shorter expires value for the Contac than what was suggested by the > user agent in the request. In this case the real expires value of the > contact will be in 200 OK and user agents are suppose to pick it up > from there and update the refresh interval accordingly. This may not > work in the case when Contact IP address is rewritten by the server > for the purpose of NAT traversal. In this case the user agent will be > unable to find its contact (because it has been rewritten) and will > not update the refresh interval (resulting in expired registrations). > > > For now, we're instructing the client to increase the timeout to 10 > > hours on the softphones in which the problem happens most often. I > > don't know if that's really the right thing to do, I think we should > > somehow make sure the re-registers are done in a timely fashion and > > retried, but I could not find ant SER configuration option related to > > that. What should I do? > > You can configure the maximum allowed expires value in SER, if a user > agent tries to REGISTER a contact with longer expires value than it > will be automatically updated by registrar to the value of > max_expires parameter. > > There is also min_expires parameter in registrar module but that one > should not be used because the current implementation violates > RFC3261. > > If you are using any of the two parameter than it might be a good > idea to retry without them (to see if the problem persists). > > Jan.

OK, the REGISTER message contains a private IP in the contact. That would force SER to rewrite the IP address with the public IP of the NAT and the user agent is probably unable to match the contact and find out what the expires value set by the server is. That explains why it works with Expires: 60 header field parameter but does not work with ;expires=60 contact parameter. There are two options: 1) Hack -- insert Expires: 50 header field into the reply using append_to_reply function from textopts module. Note that the value you insert this way must be lower than the value of expires parameter in the contact. 2) Use fix_nated_register instead of fix_nated_contact for REGISTER messages. This function does not rewrite the IP in contact, instead it would append the public IP and port used by the NAT as a parameter of Contact header field. The two values will be stored separately in the user location database. When forwarding a message to the contact, the Request-URI will contain the private IP of the user agent, but the message will be sent to the public IP of the NAT (destination set will be used). This way the Contact in 200 OK reply will be not modified and the user agent should be able to set the expires value properly. Jan. On 23-06-2005 17:59, Chia Huey Lim wrote: _______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers