A. BranchCache is a great feature and has minimal port requirements. In distributed mode, clients use WS-Discovery to discover cached content and then HTTP to transfer data between clients. In hosted mode, clients communicate directly to a local BranchCache server, so there's no discovery required. Again, clients use HTTP to retrieve content from the configured BranchCache server. When clients have content to offer to the BranchCache server for storage, they use HTTPS to communicate with the server.

The protocols used are, therefore:

  • HTTP (port 80) for content retrieval using BranchCache retrieval protocol.
  • WS-Discovery (port 3702 UDP) for content discovery in distributed cache mode.
  • HTTPS (port 443) for content upload in hosted cache mode using hosted cache protocol.