Topic Last Modified: 2011-05-02

An HTTP reverse proxy is required in your perimeter network for:

• To enable external users to download meeting content for your meetings.
  
  
• To enable external users to expand distribution groups.
  
  
• To enable remote users to download files from the Address Book Service.
  
  
• To enable access to the Microsoft Lync Web App client.
  
  
• To enable access to the Dial-in Conferencing Settings web page.
  
  
• To enable access to the Location Information Service.
  
  
• To enable external devices to connect to Device Update Service and obtain updates.
  
  

The HTTP reverse proxy provides a single discoverable IP address through which external users can download content from the internal Web Components (IIS) Servers. The Web Components Servers in turn use the reverse proxy to download expanded distribution lists, Address Book files, and meeting content for external users. All communication between a reverse proxy and internal Web servers occurs over HTTPS (TLS over HTTP) and therefore is encrypted.

For details about deploying and configuring an HTTP reverse proxy, including configuring your firewall to work with a reverse proxy, see Planning for External User Access in the Planning documentation and Set Up Reverse Proxy Servers in the Deployment documentation.