Re-registering a hardphone [closed]

Question

I've got a Linksys SPA942 hardphone connected to an OpenSIPS quasi-PBX. I want to re-register the phone manually, without rebooting, resetting, or touching the default re-registering time (3600s) Is it possible to do that by the phone? If not, how to force the re-registration from the OpenSIPS (or from any PBX)?

Answer 1

SPA942s should automatically re-register based on the option in the web interface under Admin -> Advanced -> Ext(1-4) -> Proxy and Registration -> Register Expires (in seconds). A successive registration will overwrite a previous one. As long as the phone is set to send a registration within the interval of time that the PBX will hold the registration, it will just update the registration that the PBX is holding for that line (in a standard configuration anyway, I'm not sure exactly how you have anything set up).

Answer 2

Unregistering is technical possible, you can see here for an example, or here the RFC for sip. You must see for your sipphone or your pbx manual to see how to do it on your specific system/hardware (if they follow the SIP RFC, it whould be possible to do it with some specific command.

Here is it what RFC tells about unregistering:

10.2.2 Removing Bindings

Registrations are soft state and expire unless refreshed, but can also be explicitly removed. A client can attempt to influence the expiration interval selected by the registrar as described in Section 10.2.1. A UA requests the immediate removal of a binding by specifying an expiration interval of "0" for that contact address in a REGISTER request. UAs SHOULD support this mechanism so that bindings can be removed before their expiration interval has passed.

The REGISTER-specific Contact header field value of "*" applies to all registrations, but it MUST NOT be used unless the Expires header field is present with a value of "0".

  Use of the "*" Contact header field value allows a registering UA
  to remove all bindings associated with an address-of-record
  without knowing their precise values.