Sangoma Vega 100 as an ISDN gateway to a SIP PBX

The aim is to use a Sangoma Vega 100 single port PRI gateway as an ISDN gateway for a SIP PBX.

All the Vega will do is forward anything it gets on the ISDN line to the SIP PBX and forward anything from the SIP PBX to the ISDN line.

Steps as follows:

  • Web browse to the Vega and login
  • Go to the Quick Config section
  • On the E1/T1 page, change the number for Interface 1 to just “.*” (dot-star without the quotes)
  • Ignore lines 2-4
  • Open up the Port Settings (ISDN line settings) section and check that the line is set to the correct mode, TE (not NT)
  • On the SIP tab, enter the IP or hostname of your SIP PBX into the domain and proxy settings. You do not need Outbound Proxy and it’s best to set this up without Registration
  • Apply the quick config

That should be it, the Vega will forward SIP to ISDN and ISDN to SIP regardless of numbers received on either side.

The main settings for this are in “Dial plan” in Expert Config. You can see what has been generated in the “To_SIP” and “To_E1T1” dial plans.

Note: this should also work on Vega 200 and Vega 400 if you add the other ISDN interfaces into the planner group that the dial plan “To_E1T1” uses.