At first glance it would seem integrating a NEC Univerge SV8300 PBX with Exchange 2010 UM would be a cinch considering the NEC SV8300 supports SIP trunks and Q.SIG. And the similarity between the NEAX 2000 IPS systems is uncanny. This is where our adventure begins.
We procured an Audiocodes Mediant 1K with a T1 SPAN and attempted to configure a QSIG trunk from the SV8300 to the gateway. This is an ideal setup because we can pass in band information across the trunk such as Message Waiting indicators (MWI), Calling Party ID (ANI), and DTMF.
So we configured both the SV8300 and the Audiocodes gateway and we were able to call the Voice-mail pilot number for Exchange UM. We were greeted with Welcome to Microsoft Exchange Unified messaging but we could not get integration working which means we should of heard the prompts to log into the users mailbox. We were just hitting the generic opening default greeting. We looked into the Exchange UM logs and found that diversion header information was not being passed and only the Pilot number itself was coming across. Naturally this must be an Audiocodes problem. After taking syslogs from Audiocodes we found the calling party data was not being passed at all.
Eric Houg one of our NEC gurus called up NEC and they informed us that the SV8300 does not pass calling party information across QSIG or SIP trunks. So their went the SIP trunk thought. They did mention we could swap out the system for an SV8500. That wasn't going to fly with the customer.
So we went back to the drawing board and know we have implemented several NEC and IPS systems using the Dialog DMG1008DNIW with 8 Digital Emulation Ports (http://www.voiplink.com/Dialogic_DMG1008DNIW_p/dialogic-dmg1008dniw.htm). We still were required to use a MCI serial cable for inband signaling information. MCI is NEC's version of SMDI. So we tried hooking up the Dialogic gateway and the Digital set emulation profile that the dialogic gateway supported and needed to integrates into the NEC with was too old and was not pulled forward into the NEC SV8300. So now we could not use the Dialogic gateway.
We called Audiocodes up to see if we could use FXS ports to integrate with the SV8300 on the suggestion of NEC. The Telephony advisior shows we need to use FXO analog trunk Ports with SMDI http://technet.microsoft.com/en-us/library/ee364753(v=exchg.150).aspx
We cabled up the FXO ports on the Audiocodes paired with FXS ports on the NEC. We cabled up the SMDI cable for signaling and everything was working great. Well almost great except for the Message Waiting indicator Lamp on the Phones. Exchange shows the SIP notify was successful but it obviously never made it back to the NEC and here is the reason:
Audiocodes sends MWI information in-band across the analog ports and not out of band with this old school integration and the NEC SV8300 expects to see it across the SMDI/MCI Serial cable. Essentially there is no path back for the set and cancel messages to be sent from the Audiocodes gateway and the NEC SV8300. We opened up an Audiocodes trouble ticket and it was escalated to Israel with the developers and they came to the same conclusion.
Where do we go from here you may ask? Well we are going to hop into our DeLorean and travel back to 1985 to configure DTMF integration for signaling and MWI's. Stay tuned as the future may be changed.