TPF can ask the logon manager for the name of the CLU that would provide the best path to a DLU. TPF requests a CLU assignment by sending an unsolicited REQTAIL RU to the logon manager. When the logon manager receives a REQTAIL RU with a DLU name, but no DLU subarea address, the logon manager issues a SIMLOGON to find the DLU subarea address and the COS name for the session in this network. When driven with the subsequent CINIT, the logon manager rejects the session, but uses CINIT and the original REQTAIL RU to find the best CLU. The best CLU is the one that meets the criteria described in Contending CLUs for TPF-initiated sessions. TPF will not request parallel sessions from disjoint hosts. If TPF receives a parallel session on the wrong host, it rejects the BIND with sense code 08014001. The logon manager sends a SESINIT (bind image) to the application program LU associated with the best CLU. TPF builds the BIND and sends it to the application program LU. The application program LU sends the BIND to the DLU.