This read-write value holds the 20-byte binary NSAP address identifying the local end point of this connection, structured as a 13-byte network prefix, a 2-byte Cisco vendor identifier, a reserved byte, a 3-byte logical interface field encoding slot and port number, and a final selector byte. An administrator or the connection-setup process constructs this address so the switch fabric can uniquely identify which slot and port originates this connection's local endpoint. For example, two channels on different slots of the same shelf would have NSAP values differing specifically in the slot portion of that 3-byte interface field.