Priority-Based Connection Establishment

Connection Manager supports priority-based connection establishment.

The following list describes some of the scenarios that show how Connection Manager manages various connection requests based on their priorities:

If Connection Manager receives multiple connection requests, it adds each connection request to a list. The connection that is established is the one with the highest priority.
Unless the exclusive bit is set, if a high-priority connection is established, even the lower-priority connections are active if they have the same network destination as the high-priority connection.
If a connection is already active and a higher-priority connection request for a different network destination is made, Connection Manager disconnects the active connection and attempts to establish the higher-priority connection.
If a connection is already active and a lower-priority connection request for a different network destination is made, the active connection is not disconnected. However, the requesting application can subsequently modify the priority of the connection request it already made. If the application increases the priority of the requested connection to one that is higher than the priority of the existing active connection, Connection Manager disconnects the active connection and establishes a new connection for the requesting application.
If an application requests a low-background connection (lowest-priority connection), and a cached connection to the same destination exists, the low-background connection uses the cached connection. The connection remains active as long as the low-background application uses it, even after the caching timer expires.

Additional resources