PBX replacement with MS Lync (with Dual Forking) Part 1

Talking about PBX replacement with MS Lync can be a difficult argument when proposed to customers. But as the nature of MS Lync we have a lot of ways to do it. Usually we can meet two different type of customers, one can think that his employees must change how they work day by day, and for this reasons we can explore solution with direct switch to new technology providing a direct cut-off ; the other one,  not so confident,  prefer a soft migration and possibly a true coexistence between old and new phone system, the last one obviosly is more complicated,  but surely the most funny for us:-), i want to explain  you how we can do a soft migration also with a good coexistence, for now i can mention 2 type of IP-PBX or TDM-PBX: ALCATEL OXE and Cisco CCM.

The first important thing is that all of this project must provide a Voice Media Gateway to ensure that all translation and, eventually transcoding,  from one system to Lync and viceversa don’t drive us crazy…:-)

Actual Infrastructure Enviroment without integration

PBXReplacementExample_base scenario

Based infrastructure consider that we have a fully up and running Lync enviroment and a consolidate Phone infrastracture .

Scenario  (Coexistence with Dual Forking)

If we have a ALCATEL OXE (with remote extension license), CISCO CCM (sip forking with extension mobility license) or a TDM/IP-PBX that support forking to another number not included in its dial-plan (for example to a sip trunk or TDM trunk connected) we can consider this scenario :

PBXReplacementExample_scenario1

Using  Voice Gateway between Lync and Phone infrastructure give us a lot of configuration that otherwise we could not easily do without provide a big effort from the Phone system team .

In this scenario we can consider this events :

Inbound call from PSTN : When we receive a call from PSTN to +3906….4444 , call arrive to PBX , PBX at this stage send the call to the extension in its dialplan and see that there’s also another number associated (for example 9994444) and , in parallel , fork this call to that number with 999 (a prefix trunk associated to the Voice gateway).

When the call arrive to Voice Gateway with destination number 9994444 , it translate called number in +3906….4444 and send to lync .

Result  :  Lync client (or lync phone) and PBX phone ring at the same time, and when one of this two pick up the call ,the other one stop ringing .

Inbound call from another PBX phone : When we receive a call from another PBX phone  to 4444 , call arrive to PBX , PBX at this stage send the call to the extension 4444 and see that there’s also another number associated (for example 9994444) and , in parallel , fork this call to that number with 999 (a prefix trunk associated to the Voice gateway).

When the call arrive to Voice Gateway with destination number 9994444 , it translate called number in +3906….4444 and send to lync .

Result  :  Lync client (or lync phone) and PBX phone ring at the same time, and when one of this two pick up the call ,the other one stop ringing .

Outbound call from Lync to other PBX phone : In lync we have two way to make a call to a contact, if we make a classic Lync call , this call remain inside Lync enviroment but if we make a work phone the call is translated for example in extension format :

– Digited : +3906……4444 , normalized in 4444  so the call are sent outside Lync through the Voice Gateway  and arrive to the extension 4444 , as i mention before in pbx enviroment 4444 have another extension configured (9994444) that corrisponds to the Voice gateway trunk and the same call was also diverted to Lync client .

Result  :  Lync client (or lync phone) and PBX phone ring at the same time, and when one of this two pick up the call ,the other one stop ringing .

Yes i know , a little cumbersome but it’s work fine .

Inbound call from lync to PBX and dual forked to lync

Outbound call from Lync to other PSTN: All external calls made from Lync follow the classic flow to PSTN (Voice Gateway –> PBX –> PSTN) , it’s important to know that all calls made by Lync can have the same Calling number as the associated extension in PBX dial plan :

– for example if i make a call from PBX phone my external DID is : +3906……4444, but PBX add instead of me the +3906….. (* maybe that +39 is not considered in a national call) .

When i make a call from lync if i want that it must be the same calling number as the PBX phone ,  i have to configure on Voice Gateway a good format for PBX to accept DID so for example in ALCATEL enviroment i must pass to it the call in this format :

calling number (Lync side) +3906…..4444  — >  Translated by VG in  : 06…..4444 , in this way ALCATEL recognize the call as one from its dial-plan, otherwise can appean that my calling number is only +3906……. without the extension.

Result : the call appear to PSTN exactly from one number shared by Lync and PBX and we can realize a true Single Number Reach

Requirement for this scenario

We have to consider that if we make a QSIG trunk between PBX and Voice Gateway my advice is to use a QSIG-GF (Generic Function) not basic because there are a lot of service such as call diversion, line identification, etc.. that is not implemented on QSIG-BC (Basic Call).

If we choose a SIP trunk between PBX and Voice Gateway we have to consider in Voice Gateway side licenses for IPtoIP and eventually transcoding with DSP onboard because if we configure trunk from/to PBX in a RTP codec different from G711, for example G729 , all calls are trascoded (Lync Mediation server work only in G711).

I hope that this post can be useful for you , and please don’t hesitate to comment 🙂

In part 2 we’ll consider a scenario in which I’ll describe the positioning of Voice Gateway in passthrough between PSTN and PBX to prepare a clean migration phase.

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UPDATE 1.1.5: Call Via Phone application for Lync 2010

Hi all, I developed an application  to grow the capabilities of the call via telephone in an environment that includes Lync and SNOM as ip-phone with the firmware Apollo or oldest. At this time only Lync IP-PHONE version with a “USB “Better Together” can make call via Lync 2010 Client. So with this application you can able to do also with all the SNOM UC Apollo firmware and also with the oldest SNOM OCS firmware. As most of you know the new Apollo firmware allows authentication by inserting Extension and PIN, or as an alternative, but more cumbersome, the use of username and password.

At this time it work only in Lync 2010 client , the extension of Lync 2013  is still in development.

Following all Windows version tested :

  • Windows 7 32/64 bit
  • Windows 8 64 bit
  • Windows Server 2008 R2 64 bit

Following is a brief guide:

Installation

Updated 32 bit version 1.1.5 download:  Call Via Phone app 32

Updated 64 bit version 1.1.5 download:  Call Via Phone app 64

Before install it , unistall the old version from Control Panel. This new version  solve an issue regarding “phone-context” string manged by the SNOM phone , thanks to Olivier Kiel for feedback about it.

Once installed go ahead with the setup.

Configuration

Start Lync 2010 Client and go to Tools –> Configure Call Via Phone App

After that a Message Box appear , and after fill the field (information below is not real, provide you own configuration) click to save.

 After that, you are now ready to use the call via phone app.

Using

On your buddy list , right click to a contact and click “Call Via phone”

Please give feedback and do not hesitate to contact me for any kind of information or problem.

if you want to donate to help and encourage the development you can follow this link :

Download Link :

Updated 32 bit version 1.1.5 download :  Call Via Phone app 32

Updated 64 bit version 1.1.5 download:  Call Via Phone app 64

NEWS *  : New Call Via Phone Advanced version  coming soon with this feature :

  • When you click on a contact you can choose which number call using the phone(Lync , Mobile, Work, Voice mail)

SNOM UC apollo 8.8.1.13 released

This new firmware solve all problem that i mentioned in my last post with firmware 8.8.1.11 :

  • There’s no need to have  an edge server in Lync infrastructure for Ringback issue
  • “Not registered” message on snom phone during the day.
  • Problem when you add a snom phone from a Lync based conference

For other information and to download last firmware please visit http://www.snom.com/

Let’s introduce this blog!

Hello,

anybody could ask: “Why another blog about Unified Communications? Well it’s very easy…  Simply I desire to share my day by day experience facing challenging problems that come during my work.  Another main reason is because here in Italy, compared to other countries, the Lync and Co. market is slowly growing but, compared to other vendors, it is not yet stopped. So I think it could be good to have an instrument designed  to simplify all the various phases of our work on deploy, troubleshoot, etc.. By now, thank you in advance for all your comments (I hope that will have a lot of) and for all of you that would give me feedbacks and new inputs on this.

Of course, I thank all the well-established bloggers who have helped me a lot in my work every day.