Generally when I join the weekly VUC conference all I’m dialed in from a SIP hard phone over a Junction Networks OnSIP trunk. This has historically meant that I had to dial in using the PSTN number, not the SIP URI.
A couple of times I tried to create an extension in my OnSIP account mapping their VUC SIP URI to a local four digit extension. That simply doesn’t work. The OnSIP GUI doesn’t permit the use of SIP URIs where the domain is specified by an IP address. It only accepts domains when referenced by alpha means.
While on this past weeks call I brought up an X-Lite client and configured it to login to OnSIP. I was working through using a second instance on the call to bridge the IVR examples into the call directly, as opposed to using a speaker phone like our guest did. I then entered the VUC SIP URI directly into the client. I was happy and a bit surprised to see that the call proceeded and I was able to join the conference a second time.
So from this I’ve found that OnSIP dials SIP URIs of any sort. It’s only a “feature” of the GUI that I can’t map URIs based on IP to extensions. Because of this I’ve now added the VUC SIP URI to the dialing directories provisioned to my Polycom phones so that I can join the conference toll free from now on.
Sadly, there appears to be no way to enter alpha SIP URIs to the Snom M3 and also no way to provision the dialing directory externally (at the moment.) Thus in order to be cordless I have to either start the call from a desk phone then transfer to the cordless, or establish a numeric VUC extension in Asterisk and dial that on the Snom.
In the future phones need to be designed to more easily accommodate SIP URIs.