Today, mobile employees need access to presence-enabled communication (voice/IM) both within the enterprise and outside of it. Single-Number Reach is a way for enterprise users to hand out a single identity and be reached wherever and on whichever device. With Single-Number Reach, mobile employees can now manage a corporate identity and personal identity on the same wireless device.

Enterprise Cellular Telephony is a feature of Office Communications Server 2007 R2. It provides the ability for a user to use Communicator Mobile to set up and control voice calls over the circuit-switched network.


The following figure is an example of a Communicator Mobile topology, and the various servers and signaling that occurs.

Single Number Reach Topology

Single-Number Reach Features

Single-Number Reach, in combination with Office Communications Server 2007 R2, enables valuable scenarios for users of Communicator Mobile. The following table describes a few features commonly used by Communicator Mobile users.

Feature Description


Call SIP URIs and telephone numbers from contact list and smart search results.

SNR - Incoming

Receive calls dialed to their single number on their Communicator Mobile device.

SNR – Outgoing

Make calls from their Communicator Mobile device. The caller-ID received reflects their single number.

Deflection services for voice mail

Incoming calls may be deflected to other targets – for example, voice mail.

Server Roles

To implement Single-Number Reach in an Office Communications Server 2007 R2 environment, some additional server roles and technologies are required.

Dependency Description

Call Control Server

Sets up calls between the cellular device and the remote party

Mediation Server

Calls that exit the enterprise voice network exit by the Mediation Server

PSTN Gateway

Used to connect a VOIP network to the traditional Public Switched Telephone Network (PSTN)