The Edge Server role in Lync Server comprises three separate subroles just as in previous versions of the product: Access Edge Server, Web Conferencing Edge Server, and A/V Edge Server role. Each role provides slightly different functionality and depending on the organization’s requirements it might not be necessary to use all three services. With Lync Server 2010, all three roles are deployed together as opposed to individually like in previous product versions.

Unlike many of the internal roles, the Edge Server does not require database or file shares because it does not store data other than the Local Configuration Store replica from the Central Management Store. Because the Edge Server is designed to be deployed in a perimeter or DMZ network, it runs a limited set of services to make it as secure as possible. Edge Servers are also typically not joined to the internal Active Directory domain, but can be if necessary. The different Edge Server roles provide unique features, as shown in Figure 1. The reverse proxy server also provides some external services through the Front-End pool.

 

Figure 1. Lync Server External Access

 

Access Edge

The Access Edge role serves as the core of the Edge Server and is responsible for all of the signaling functionality. Without the Access Edge role deployed, the Web Conferencing Edge and A/V Edge roles cannot function. The Access Edge also serves a few distinct purposes including remote access, federation, and Public IM Connectivity.

 

Remote Access

One function of the Access Edge Server is to provide remote access capabilities to a Lync Server infrastructure. After an internal deployment of pools is complete, an Access Edge Server can be provisioned to enable users to sign in and use their endpoints across the Internet.

As long as the appropriate SRV records exist in DNS or the client is manually configured correctly, a user can travel in and out of the office without ever making a change to an endpoint. This enables users to have full access to their internal features regardless of location.

 

Note

Access Edge Server traffic is performed using port 443 over TCP, which is the standard for HTTPS traffic. Traffic is rarely blocked or interfered with by any kind of proxy or firewall software.

 

文章比较长，我截了一部分，感觉介绍的灰常不错，其来自链接：http://tutorial.programming4.us/windows_server/microsoft-lync-server-2010-edge---edge-overview.aspx