RECOMMENDATIONS SCCP <--> SIP under PIAF

[henry]

This is just a footnote to the excellent thread (now closed) started by rjaiswal

He writes "In the add extensions screen, use "SCCP/(ext. number)" as the dial string."

From my experience this works perfectly on a SCCP-only telephony network.
If you decide to mix up multiple protocols - SCCP, SIP, IAX, UNISTIM - and run them all
off of the same Asterisk install, the dial string that worked for me was <prot>/<ext.#>@<ext.#>.
Without the last @<ext.#> you can't use the SCCP/UNISTIM phones to receive calls from SIP phones.
Calling from them works even without that addition...

This can be very useful when running home phones over SCCP but needing to call in using softphones..

It is not really my discovery. I got it from here some time ago when fiddling with USTM.
http://forums.asterisk.org/viewtopic.php?f=1&t=81923
As it turns out, it is the solution to ANY custom extension, including SCCP...

 

[rjaiswal]

Thank you for the update! I've only used SCCP with SIP. No other custom extensions. I wonder if you need the @<ext> with IAX extensions as well...

 

[henry]

That is my experience, yes.

To generalize:
In order to bridge two devices, one of them using standard (SIP, IAX) and the other custom (SCCP, USTM) extensions,
and make possible communication between them regardless which endpoint initiates the connection (aka places the call),
the custom extension has to use @<ext> at the end of the dial string...

I use mostly IAX (Zoiper on a smartphone) because of the simplicity to traverse routers...

 

[islandtech]

Added a chan sip extension to my asterisk 13, latest chan-sccp-b driver without changing the dial string.
Can make and receive calls between the sip and sccp extension, transfer back and forth, and pick up a calls from either device.

 

[henry]

This never worked for me.
Last time I tried was a few weeks ago...

Was the SCCP device a softphone?
I tried only with Cisco 79XX IP phones...

 

[islandtech]

phones are Yealink SIP T20 and Cisco 7931G 2 of each

 

[henry]

Can you try (any) SIP softphone instead of the Yealink?

 

[islandtech]

using telephone app for the mac i called the 7931g ext, then called a yealink t20
placed a call from the yealink to the softphone, answered then transfered it to the cisco phone
placed a call from cisco to softphone, answered then transfered it to the yealink ext