Lync and Voice -who's done this?

[SJCA53]

I work for an engineering company of about 200 people in 12 locations with a separate Data center maintained for companywide resources like Exchange, Lync and our current financial software and SQL databases.

Right now we are using an Avaya IPOffice phone system with IPOffice controllers in each office and centralized voicemail baased out of our Corporate office. We have a WAN across all our sites that carries data, voice and minimal video. We have had VoIP internally since 2002, but our external voice connections are a mix of analog and PRI from multiple vendors.

We are interested in Lync with Voice, but would really like to find someone else that has done this and can share knowledge on using SIP trunking and how voice integrates with Lync in a multiple site real environment. We've heard all the sales pitches, so we basically understand the capabilities, but we really need first hand knowledge of the process, pain points, challenges,etc.

I will be posting this in the Lync forum and if there is one on SIP trunking and/or VoIP I will post that there as well.

 

[58sniper]

The big issue is going to be cost, and at what point do you need SBAs or gateways in the branch offices vs. traversing the WAN. WAN latency will show up more in Lync than anywhere else, usually.

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[Billz66]

How about sip trunking into the avaya to provide a method of migration from one to the other , eventually you could remove the trunks and convert to a carrier sip trunk solution.

 

[kevinmpeters]

OK, I'm rather late to this thread, but figured I'd chime in just in case.

I have to disagree with the statement above: "WAN latency will show up more in Lync than anywhere else, usually". This statement could be taken as Lync is not as good at dealing with latency as other VoIP systems (although I don't think it was meant that way). Lync, like anyother VoIP system is impacted by things like latency and jitter, however it is definitely not a case where it is more susceptible than other VoIP systems, in fact in many cases it handles jitter and latency better than other VoIP systems. The Lync client has a built in jitter buffer and audio healer, these do wonders for choppy networks with poor performance. Lync is definitely more susceptible to latency and jitter than AD for example though.

Latency wise, Lync is like any other VoIP system, it relies on the network, as a general rule a latency of less than 250ms roundtrip is recommended. You can also work with your provider to enable QoS on the WAN links to ensure delivery of time sensitive media packets.

As far as deploying Lync with voice or as a PBX I've been involved in literally dozens of projects where Lync was the only PBX in use. A few of he key things to remember are:
* Right sizing your WAN links and networks
* Understanding media traversal from the external side and sizing your internet connections appropriately
* Not utilizing VPN as a transport for real time media for internal or external users
* Placing SBA's and some type of local PSTN connection in locations that require survivablity
* Working with your PSTN vendor to enable Lync to send and receive 11 digits (in the US)
* Utilizing Certified devices for a quality user experience

As far as SIP trunking specifics, there really aren't many, typically the SIP trunk provider will place an SBC at your site, this needs to be a certified Lync gateway. If the SBC is not anchoring media, then you'll want to configure the PSTN NIC of your mediation servers to route that traffic (if you are using dedicated mediation servers with dual nics). Also, make sure the SIP trunking provider supports G.711 or the SBC they provide is capable of transcoding from whatever protocol they supply to G.711 (and can handle the transcoding workload).

HTH
Kevin

 

[58sniper]

Sorry, Kevin. I didn't mean to imply that Lync wasn't up to the task. I meant that compared to, say, a file transfer, latency will be more obvious in voice and video. Quality routing and switching equipment and configuration will help Lync, and any VoIP solution succeed.



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