Voice and Video Edge Architecture

Communications Server can support voice and video calls from remote users and trusted remote sites over the Internet. Shown here are the major components required to securely route voice and video calls over the Internet without first establishing a virtual private network (VPN) connection. This supports both remote users (e.g., home or mobile users calling over the Internet) and “federated” remote sites—sites belonging to remote business partners (e.g., contractors) that the organization allows to use its voice and video system and that it trusts to authenticate their own users.

The most important Communications Server edge components are as follows:

Access Edge Servers. Access Edge Servers encrypt Session Initiation Protocol (SIP) call signaling traffic against eavesdropping and support server authentication for remote users and federated sites. Access Edge Servers can also perform filtering tasks, such as blocking traffic from untrusted addresses. However, Access Edge Servers do not authenticate remote users, which must be done inside the organization or by federated sites. The Access Edge Server component was called the Access Proxy in previous versions of Communications Server and continues to support Access Proxy functions from previous versions, such as connecting to public IM networks.