Enterprise Voice Features in Lync 2010
OCS 2007 had great voice features but it wasn’t fully redundant and lacks a lot of high availability features. For example, failure in a central OCS server might result in loss of banch office voice services. Usually, failure in central office might cause an enterprise to lose all its functionalities. Lync 2010 introduces a lot of features that mitigate these issues. Lync 2010 allows implementation of a single frontend pool split across two data centers. In this case, both pools operate as one system and loads are shared across data centers and SQL is clustered between two data centers.
Call Admission Control
Lync 2010 introduces CAC as known as Call Admission Control. In a nutshell Call Admission control is an application level QOS (Quality of Service). You can use policies to control users calls that may affect the quality. It is designed to protect a network from large storm of audio and video traffic. This also prevents users from hogging all the bandwidth and degrading performance of other users. This allows administrators to provide a service level guarantee to end users.
Support for E911
As you know, big challenge of VOIP systems are ability to use 911 services. Although out bound for 911 is possible, it not easy to determine the originated location. This makes 911 dispatcher life harder as they will need to ask 911 caller where they are located. Lync 2010 introduces new feature called E911. This location information comes from a client through the SIP truncks to a third-party partner. Below is high level overview of 911 calls in Lync:
- The client makes a 911 call and it includes the location and E.164 number in the SIP packet.
- Lync recognize the 911 number and routes it to the SIP trunk leading to E911 Service point (third-party).
- The third-party provider may conference in on-site security personal if needed.
New Mediation Server Features
Back in OCS days, it was required to maintain a one-to-one ratio of gateways and Mediation servers. This is no longer the case in Lync 2010. With Lync, one Mediation server can now manage multiple gateways. Mediation server can now deploy as a pool to avoid single point of failure. This pool can also be collocated with FrontEnd server saving hardware. This feature allows far more flexibility and scalability.