JES2 systems have a feature called the network path manager; other IBM® networking packages (for example, JES3 and RSCS) do not. The JES2 network path manager maintains path information for all connections between NJE members (nodes). Each JES2 member of the NJE network has a copy of the path manager. The path manager determines the best paths to the various nodes and maintains information about the status of the network.

Path manager processing is essentially the same for SNA, BSC, or TCP/IP NJE. Each path manager can have a consistent picture of the network at any given point in time. As nodes make and break connections in the network, the path managers at the various nodes broadcast their views of the network through network connection control (NCC) records to directly attach nodes and update internal routing tables based on the information they receive. The path manager issues message $HASP500 when various NJE signon and connectivity problems occur. See z/OS JES2 Messages for the list of associated reason codes and their meanings.