Integrating Asterisk with the Avaya Merlin Magix PBX

I recently needed to replace the voicemail server for a customer with a flexible alternative. We weren't in a position to remove the Avaya Magix PBX, so continued (and seamless) integration was still necessary. The only problem was the integration between the two systems. The connection was easy enough: 8 FXO ports in the Asterisk server using 2 4-port Digium TDM cards connected to the 8 analog or "single line" extensions from the 016 card in the Avaya. But, with different scenarios on call-in (voicemail check, roll-over to voicemail, inbound call, etc), Asterisk would need to behave differently, so how would this be accomplished?

In short, it's really simple. Avaya/Lucent use what some call "mode code", or DTMF digits used to "direct" the voicemail system as to the type of inbound call. The original server used analog lines as well, so determining those mode codes was simple as attaching a digit grabber and watching the digits come across as different voicemail calls were made.

The following was crafted in my dialplan to route the calls properly:

Mode Code Integration

Beware - the following syntax will probably need to be reviewed for compatibility with later versions of Asterisk. This stuff was used on a v1.0 box.

 ; The following extensions grab the mode code
 ; coming from the Avaya PBX and route the
 ; call appropriately via the Voicemail()
 ; and VoiceMailMain() apps.
 ;
 ; someone pressed vmail check
 exten => _#XX#XXXX##,1,VoicemailMain(${EXTEN:4:4})
 exten => _#XX#XXXX##,2,Hangup()
 ; inside call rolled over to vmail
 exten => _#XX#XXXX#XXXX#,1,Voicemail(u${EXTEN:9:4})
 exten => _#XX#XXXX#XXXX#,2,Hangup()
 ; inside group call rolled over to vmail
 exten => _#XX#XXXX#XXX#,1,Voicemail(u${EXTEN:9:3})
 exten => _#XX#XXXX#XXX#,2,Hangup()
 ; outside/PSTN call rolled over to vmail
 exten => _#XX##XXX.,1,Voicemail(u${EXTEN:5:4})
 exten => _#XX##XXX.,2,Goto(s,7)
 ; outside call went direct to Asterisk box (call from PSTN) 
 exten => _#XX#XXX#,1,Wait(1)
 exten => _#XX#XXX#,2,Goto(s,7)

The only additional step is to ensure you do a WaitExten(1) right after answering as this is the timeframe when the mode code digits are sent across.

From here, you can do what you wish as far as giving your users the ability to leave and check voicemail, not to mention build a very nice automated attendant. As a side note, the Magix analog lines expect calls to be transferred by using the Flash() application, then SendDTMF(XXXX).

Voicemail or MWI (Message Waiting Indicator) Light Integration

The only thing left is to operate the voicemail lights properly, which again is accomplished by the Magix PBX using DTMF codes: *53XXXX for on, and #*53XXXX for off. This is accomplished by adding the following directive in your voicemail.conf:

 externnotify=/usr/local/bin/vmnotify.pl

As well as adding the required script, the original listed here, and a backup listed here. Huge thanks to the original author, Mike Cathey.. Mike's website.

The script requires a few additional directories which are spelled out in the script's contents. Just browse through and make whatever changes you require. It also contains the ability to perform outbound calling when there's messages waiting, but I haven't needed it and thus haven't used or tested it.

See also

• Asterisk Legacy Integration
• Asterisk MWI