(Item 008495) DLUR CP-SVR pipe persistence ------------------------------------------ The current DLUR/S architecture requires: a) the DLUR and DLUS to activate a CP-SVR pipe only when a PU requires activation, and b) the DLUS to deactivate a CP-SVR pipe when there are no pending or active SSCP-PU sessions associated with it. There is a customer requirement for DLUR's duplicate TIC support to match NCP's. To achieve this, a CP-SVR pipe must be allowed to be activated and to remain active even when there are no associated PU or LU sessions. The proposed solution includes the following: 1) Provide a new DLUR/S capabilities indicator for support of CP-SVR pipe persistence (byte 9, bit 6 in CV X'51') which a) when set by the DLUS indicates support for CP-SVR pipe persistence in general b) when set by the DLUR indicates a request for CP-SVR pipe persistence for this particular pipe 2) CP-SVR persistent pipe activation: a) If the CP-SVR pipe persistence indicator is set by both DLUS and DLUR during pipe activation, then the CP-SVR pipe is considered persistent. b) DLUR processing will vary depending on whether or not there is a PU needing service and whether the DLUS supports (uplevel) or does not support (downlevel) pipe persistence. PU Needing Service ------------------ A DLUR which supports CP-SVR pipe persistence can activate a persistent CP-SVR pipe if there is an associated PU requiring activation, just as long as there is no currently active pipe to that DLUS. In this case the DLUR will include a REQACTPU RU in the FID2 Encapsulation (X'1500') GDS variable it sends to the DLUS during DLUR-initiated CP-SVR pipe activation. The DLUR will send a GDS X'1500' with the RU and a CV X'51' indicating support of CP-SVR pipe persistence. i) A DLUS which supports CP-SVR pipe persistence will accept a GDS X'1500' with a REQACTPU RU when the CV X'51' indicates support of CP-SVR pipe persistence, and the DLUS will respond with a GDS X'1500' with a RSP(REQACTPU) RU and a CV X'51' indicating support of CP-SVR pipe persistence. ii) A DLUS which does not support CP-SVR pipe persistence will accept a GDS X'1500' with a REQACTPU RU when the CV X'51' indicates support of CP-SVR pipe persistence, and the DLUS will respond with a GDS X'1500' with a RSP(REQACTPU) RU and a CV X'51' indicating non-support of CP-SVR pipe persistence. At this point the DLUR can either: - accept the non-persistent pipe and continue session activation, or - it can terminate the pipe, using DLUR/S capabilities mismatch processing, and attempt to activate a persistent pipe with a different DLUS. No PU Needing Service --------------------- A DLUR which supports CP-SVR pipe persistence can activate a persistent CP-SVR pipe if there is no associated PU requiring activation, just as long as there is no currently active pipe to that DLUS. In this case the DLUR will not be required to include a REQACTPU RU in the FID2 Encapsulation (X'1500') GDS variable it sends to the DLUS during DLUR-initiated CP-SVR pipe activation. The DLUR will send a GDS X'1500' without an RU and with a CV X'51' indicating support of CP-SVR pipe persistence. i) A DLUS which supports CP-SVR pipe persistence will accept a GDS X'1500' without an RU when the CV X'51' indicates support of CP-SVR pipe persistence, and the DLUS will respond with a GDS X'1500' without an RU and with a CV X'51' indicating support of CP-SVR pipe persistence. ii) A DLUS which does not support CP-SVR pipe persistence will, upon receipt of a GDS X'1500' without an RU, deactivate the CP-SVR pipe using UNBIND-initiated forced deactivation with a new sense data: X'08A0 000C' DLUS-DLUR Session Deactivation (Disruptive): The DLUS received a CP-SVR pipe activation request without a REQACTPU; DLUR should activate a DLUS-DLUR session with a different DLUS if possible - A DLUR receiving an UNBIND with this sense data will understand it attempted to activate a persistent pipe with a downlevel DLUS and will then try to activate a persistent pipe with another DLUS (if any). - Backlevel DLUSs will be PTF'ed to send the new X'08A0 000C' sense data. 3) CP-SVR persistent pipe deactivation: a) When the number of current and pending SSCP-PU sessions associated with a persistent CP-SVR pipe reaches zero, the DLUS will leave the pipe active. b) The DLUS can deactivate a persistent CP-SVR pipe using UNBIND-initiated forced deactivation with previously architected disruptive or nondisruptive sense data as appropriate. c) If the number of current and pending SSCP-PU sessions is zero, the DLUR can deactivate a persistent CP-SVR pipe using UNBIND-initiated forced deactivation with a new prsistent sense data: X'08A0 000D' DLUS-DLUR Session Deactivation (Persistent): The DLUR is initiating deactivation of a persistent DLUS-DLUR session.