The Protocol-Specific Function for ISDN User Part (PSF – ISUP) adds the Fault-Tolerant/High-Availability (FT/HA) functionality to the ISUP software, enabling it to execute in an active/standby architecture for High Availability systems.
PSF – ISUP (FT/HA) updates the ISUP state information from the active side to the standby side so that, in case of failure, the standby can assume operations with minimal or no disruption to the system. PSF – ISUP will help in providing distribution capabilities to the ISUP software.
The PSF – ISUP software can be combined with the portable ISUP software to operate the ISUP software in these environments:
- Pure FT/HA systems
- Pure Distributed systems: The ISUP software is not Distributed, but the PSF – ISUP software is compatible with the DFT/HA architecture.
- Distributed FT/HA systems: The ISUP software is not Distributed, but the PSF – ISUP software is compatible with the DFT/HA architecture.
Trillium PSF – ISUP enables telecom equipment manufacturers of soft switches, signaling gateways, signal transfer points, service control points, media gateway controllers or other products to:
- Accelerate time to market
- Reduce development costs
- Reduce project risk of internally developed ISUP applications
Product deliverables consist of C source software, documentation, training, a warranty and technical support.
- Supports the warm start procedure of the peer ISUP (PSIF – ISUP) for making it standby from OOS. PSF – ISUP does not delay data traffic processing during the warm start operation.
- Enables ISUP (PSIF – ISUP) to handle protocol events during the warm start procedure. The active PSF – ISUP performs the warm start state update in multiple schedulings of ISUP (PSIF – ISUP) so that other processes do not starve; therefore, protocol events can be handled by ISUP (PSIF – ISUP) between state updates.
- Supports the operator-initiated switchover allowing for the standby node to become active, and vice versa (controlled switchover), which prevents the loss of states.
- Supports the forced switchover procedure when the active ISUP (PSIF – ISUP) becomes OOS. Upon switchover, the standby PSF – ISUP becomes active and resumes operating with the current stable states.
- Provides the functionality to abort an ongoing warm start state update or controlled switchover state update.
- Supports the run-time state updates to keep the standby ISUP (PSIF – ISUP) synchronized with the active ISUP (PSIF – ISUP).
- Disables the run-time state update from the active node to the standby node when the standby becomes OOS.
- Supports the shutdown procedure that resets the PSF – ISUP states and deallocates the memory allocated by PSF – ISUP for its operation up to the time of the shutdown.
- Generates alarms upon finding failures during the PSF – ISUP operation.
- Generates debug prints if enabled by the layer manager.
- Provides the multiple point codes implementation, which updates the interface ID information to the standby side.
- Provides the multiple SAP feature, enabling ISUP to be fault-tolerant in decomposed media applications. PSF – ISUP can work when ISUP has one of the lower SAPs as MTP3 and the other as M3UA for the same/different variant.
- Supports the multirate connection feature, according to the ITU97, ANS95 and ETSIv3 variants.
- PSF – ISUP is compatible with the DFT/HA architecture for Distributed and Distributed Fault-Tolerant systems.
- The PSF – ISUP software works with all the options supported by Trillium ISUP software.
- Supports the Rolling Upgrade feature to upgrade the software, which allows upgrading a system to a new version of the software without taking the system offline or interrupting service.
- Conforms to Trillium Advanced Portability Architecture (TAPA)
- Benefits of licensing Trillium software from Radisys
PRODUCT INTERWORKING
The PSF – ISUP (FT/HA) software interworks with Trillium ISDN User Part (ISUP) software, and PSIF – ISUP software, protecting them both from failure.
CONFORMANCE
The PSF – ISUP (FT/HA) software conforms to:
- Trillium Advanced Portability Architecture (TAPA)
- ITU92, Reference: Q.761-Q.764 (1993)
- Q.767, Reference: Q.767 (ITU 1991)
- ANS88, Reference: T1.113 (1988)
- ANS92, Reference: T1.113 (1992)
- ETSI, version 2, Reference: ETS 300 356
- FTZ, Reference: 163 TR75.95
- Telcordia, Reference: GR-317 and GR-394
- NTT, Reference: NTT Q.761a-Q.764a and Appendices 4 and 5
- Singapore Telecom, Reference: Common Channel Signalling System N.7. Singapore Telecom, 1998
- Russia ISUP, Reference: ISDN User Part Specifications for the National Network of Russia, Compliance Statement, 1988
- Italy ISUP, Reference: ISUP-S ISDN User Part Specification, Telecom of Italy, 1988
- ITU97, Reference: Q.761-Q.764 (1997)
- ANS95, Reference: T1.113 (1995)
- ETSI, version 3, Reference: ETS 300 356-1, v3.2.2 (1998)




