Supplementary Telephone Services for MGCP FXS Phones

[johnsnave1]

Hi,

I have a VG350 configured as MGCP from CUCM ver 105. I have a number of analog phones connected as loop-start. The phones work ok; however, some of the users want the ability to have services such as hold and transfer. Will I need to reconfigure the VG350 as SCCP? Or, is there a way of keeping MGCP?

If moving to SCCP, is there a way to implement class of restriction? At present, all of the class of restriction is handled through the CUCM CSSs/Partitions.

Many thanks, John.

[Chris Deren]

You are correct, only SCCP provide supplementary features on analog devices.  To answer your question "YES" SCCP devices look just like other phones in CUCM and have CSS per device and line.

[Jonathan Schulenberg]

Just a reminder that SCCP does not support protocol-based T.38 fax relay. If you have a SIP trunk to the PSTN and the carrier supports T.38 (or other gateways that don’t support NSE-based switchover) you likely need to keep the fax machines on MGCP. That is, assuming throwing them in the dumpster isn’t an option.

[Chris Deren]

Great point @Jonathan Schulenberg (+5), what I do in my deployments when analog phones and faxes/modems need to coexist on the same analog GW is provision X number of ports with SCCP for phones and remaining ports as SIP for faxes/modems which support protocol-based T.38, you can use MGCP instead of SIP if preferred though.