Hi,

Passing on this article on support for ACME Session  Border Controllers (SBC) for OCS 2007 R2.

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

1. Mediation Server connecting directly to the SBC in the service provider’s SIP trunk network infrastructure
   
2. SBC deployed in customer’s network perimeter
   
3. SBC connected to the IP-PBX

Unfortunately it's not supported to put the SBC in front of the OCS 2007 R2 EDGE Server as outlined here:

Configuring an SBC for any 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 Communications Server clients must connect directly to the Edge Server to maintain the integrity of the end-to-end communication between clients and Edge Server.