This Integer32, ranging from -1 up to the 32-bit maximum, has no source description but its name indicates the first port number in a NAT port range associated with the pool. An admin uses a bounded port range like this to control how PAT (port address translation) carves up a single public address's port space among many internal hosts. For example, an admin might set this to 1024 to keep the pool from reusing well-known ports below 1024 for translated sessions.