On the server-side appliance, branch warming improves performance by keeping track of data segments created while Client Accelerator users are in a SteelHead-enabled branch office. When the user leaves the branch office, the Client Accelerator endpoint software provides warm performance. Warm performance in networking refers to the enhanced efficiency and reduced latency that occurs when previously transferred data or segments are reused, rather than retransmitted across the network. It is particularly important in environments with acceleration technologies like WAN optimization, where data is stored and indexed for quick access, improving the speed of future data transfers. This feature is enabled by default.

Data transferred by one endpoint at the branch is stored in the branch SteelHead’s data store. This benefits all endpoints at the branch, as they can access this "warm" data, improving performance.

These requirements must be met for branch warming to work:

Branch warming doesn’t improve performance for SSL connections, out-of-path with fixed-target rules deployments, and Client Accelerator endpoints that communicate with multiple server-side appliances in different scenarios. For example, if a Client Accelerator home user peers with one server-side SteelHead after logging in through a VPN network and peers with a different server-side SteelHead after logging in from the branch office, branch warming doesn’t improve performance.