Support for AudioCodes Enterprise Session Border Controllers in Lync Server 2010 and Office Communications Server 2007 R2


Microsoft Lync Server 2010 communications
software and Microsoft Office Communications Server 2007 R2 interoperates with AudioCodes
Enterprise Session Border Controllers (SBCs) when used with SIP trunking to
Internet telephony service providers (ITSPs). This article describes the
supported topologies for using Lync Server 2010 or Office Communications Server
2007 R2 with AudioCodes’ SBCs.

Author: Wajih
Yahyaoui

Publication date: February 2011

Product version: Microsoft Lync Server 2010 and Microsoft
Office Communications Server 2007 R2

Lync Server 2010 and Office Communications Server 2007 R2 now support the
AudioCodes Enterprise Session Border Controllers (SBCs). Supported topologies
are described in this article. AudioCodes and Microsoft partner to regularly
test releases of Lync Server and Communications Server, and Microsoft Exchange
Server to ensure support of Unified Communications Open Interoperability
Program (UCOIP) certified service providers that use the AudioCodes SBCs to
connect enterprises into their SIP trunk services. AudioCodes has also joined
Microsoft in the Unified Communications Interoperability Forum (UCIF),
ucif.org, as a founding member.

While SBC
is not required to deploy a SIP trunk for Lync Server and Communications Server
2007 R2, some Internet telephony service providers (ITSPs) may require that you
deploy an SBC as an element of your network that is managed and owned by the
service provider to connect to their SIP trunk service. This requirement may
occur for several reasons, such as the following:

  • Interworking
    functions
    The service provider may support only specific
    signaling and media functions that are not supported by your environment. By
    deploying a managed SBC, the service provider can resolve these differences.
  • Codecs
    compatibility
    The service provider may choose to use a
    codec other than G.711 or RTAudio. The SBC converts the codec at the perimeter
    of the customer’s network.
  • Quality
    of service
    By deploying an SBC within the customer’s
    network perimeter that is managed by the ITSP, the service provider eliminates
    many of the complexities of interoperating with the customer’s systems and can
    guarantee better service quality.

There are three supported deployment topologies for using the AudioCodes SBCs
in conjunction with Lync Server or Communications Server 2007 R2. The first two
models involve connecting the Mediation Server directly to an AudioCodes SBC.
These deployment models are shown in Figure 1 and 2. Figure 3 illustrates
another option. These deployment models are supported only when used for SIP
trunk services that have been qualified through UCOIP.

Figure 1 illustrates the Mediation Server connecting directly to the
AudioCodes SBC in the ITSP’s SIP trunk network infrastructure.

Figure 1. Mediation Server connecting directly to the SBC
in the service provider’s SIP trunk network infrastructure


Figure 2 illustrates the Mediation Server connected to an AudioCodes SBC
that is on customer premises but is managed by the service provider. This SBC
is deployed in the customer’s network perimeter, which then links the SIP trunk
to another SBC in the service provider’s SIP trunk network infrastructure.

Figure 2. SBC deployed in the customer’s network perimeter

Figure 3 illustrates the SBC connected to the IP-PBX, and the IP-PBX
connected to the Mediation Server through Direct SIP. In this topology, SIP
trunk connectivity for the Lync Server or Communications Server environment is
provided through the enterprise’s existing IP-PBX environment (which has an
existing SIP trunk to the ITSP). This configuration requires that Direct SIP
connectivity is supported for your particular IP-PBX. You can determine whether
your IP-PBX is supported by Lync Server or Communications Server 2007 R2 by
visiting the UCOIP site.

Figure 3. SBC connected to the IP-PBX

Configuring an SBC for scenarios other than SIP trunk topologies is not
supported. For example, configuring an SBC to interconnect to an Edge Server is
not supported (Figure 4) because Lync Server and Communications Server clients
must connect directly to the Edge Server to maintain the integrity of the
end-to-end communication between clients and an Edge Server.

Figure 4. SBC connected to an Edge Server (not supported)

Summary

Microsoft and AudioCodes have collaborated to support direct connectivity
deployment models between Microsoft Lync Server, Mediation Server,
Communications Server 2007 R2, and AudioCodes Enterprise SBCs.

Additional Information

To learn more, check out the following articles:

Lync Server Resources

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Keywords: SIP trunk, telephony, ITSP, SBC, interop,G,711,
RTAudio, network, UCOIP,

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