The February 2012 update to Microsoft Lync 2010 provides new functionality for the Remote Call Control feature, commonly known as RCC. With this enhancement, RCC enabled users can initiate and answer peer-to-peer Lync video calls and use Lync to join online meetings with video enabled.

Author: Jamie Stark

Publication date: February 28, 2012

Product version: Lync Server 2010

Remote Call Control (RCC) is a feature with a long history, dating back to Live Communications Server 2005 SP1. The basic capability of RCC is enabled by communicating with a PBX using a Computer Telephony integration (CTI) link between the PBX and a Lync Server pool based on the ECMA TR/87 standard. For end-users, the core capability this feature delivers is click-to-call using a user’s existing PBX phone and PBX-based binary presence update (such as to In a Call).

As a side note, this capability is completely unrelated to the Enteprise Voice functionality available with Lync. With Enterprise Voice, users have the ability to use Lync as a complete softphone (dialing internal, federated, and PSTN contacts), along with IP-based desk phones that connect directly with the Lync server.

While the capabilities of Remote Call Control were largely unchanged through the last four releases, with Lync 2010 changes were made that required video calling for RCC-enabled users to be unavailable.  

The February 2012 update to Lync 2010 adds two video call scenarios for RCC-enabled users. With this enhancement, RCC enabled users can initiate and answer peer-to-peer Lync video calls, join conferences with audio and video enabled using Lync, and continue to use RCC for its core purpose of controlling the PBX desk phone and binary presence update. The KB covering the update is available at An update is available for RCC enabled users to make video calls or conference calls in Lync 2010.

For RCC-enabled users to make peer-to-peer video calls and join video conference calls, they need a webcam and a headset, handset, or speakerphone for their workstation or laptop. Additionally, the user’s RCC policy needs to be set to Remote Call Control as opposed to Remote Call Control Only. For more information, see Enable Lync Users for Remote Call Control in the Technical Library.

The update does not support the scenario known as Split AV, where audio is delivered through the desk phone and video comes through the Lync client. The Split AV scenario provides an inconsistent and oftentimes suboptimal end-user experience, because the audio and video use different network paths and frequently lose sync. This means when a user starts an audio call using a PBX phone, they cannot add video to that call. If a call is started using the Lync client as the audio endpoint, it can be escalated to include video.

The February 2012 update is all client-side with Lync 2010. There are server-side updates as a part of this cumulative update, but nothing is required server-side for RCC-enabled users to take advantage of video. Similarly, customers can also use Office Communicator 2007 R2 to leverage the video capability of RCC against a Lync Server 2010 backend. Naturally, we recommend that customers apply the cumulative update to both server and client side and use Lync 2010.

Summary

For video capability with RCC-enabled users, deploy the February 2012 update for Lync. There is no additional information at this time about future releases of Lync. With the exception of this scheduled update, there are no additional planned changes for the RCC feature set. Should any plans arise, we will announce them publically as soon as we can.

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