Glossary P

Path protection

The working principle of path protection: When the system works in path protection mode, the PDH path uses the dual-fed and signal selection mode. Through the tributary unit and cross-connect unit, the tributary signal is sent simultaneously to the east and west lines. Meanwhile, the cross-connect matrix sends the signal dually sent from the opposite end to the tributary board through the active and standby buses, and the hardware of the tributary board will selectively receive the signal from the two groups of buses automatically according to the AIS number of the lower order path.

Performance register

Performance register is the memory space for performance event counts, including 15-min current performance register, 24-hour current performance register, 15-min history performance register, 24-hour history performance register, UAT register and CSES register. The object of performance event monitoring is the board functional module, so every board functional module has a performance register. A performance register is used to count the performance events taking place within a period of operation time, so as to evaluate the quality of operation from the angle of statistics.

Performance threshold

Performance events usually have upper and lower thresholds. When the performance event count value exceeds the upper threshold, a performance threshold-crossing event is generated; when the performance event count value is below the upper threshold for a period of time, the performance threshold-crossing event is ended. In this way, performance jitter caused by some sudden events can be shielded. A few performance events only have one threshold, which is the special case that upper threshold and lower threshold are equal.

PMU

As one type of power and environment monitoring unit, PMU (short for Power Monitoring Unit) is installed on the OptiX 155/622B, the OptiX 155/622, the OptiX 2500, the OptiX 2500+, the OptiX BWS 320G NE, and the OptiX 10G(Metro 5000).

Port inversion

It is to set port alarm monitoring as contrary to the practical situation. If an alarm is raised, it is reported normally. This function applies to a port configured with but not loaded with services to prevent the generation of any meaningless alarm that will interfere with alarm analysis.

Power and environment monitoring unit

The power and environment monitoring unit is installed at the top of the cabinet of the SDH equipment and is used to monitor the environment variables, such as the power supply and temperature. With external signal input through the relay, fire alarm, smoke alarm, burglary alarm, etc. can be monitored as well. With the display on NM system, the change of environment can be monitored timely and accurately. For the equipment installed with a power & environment monitoring board, the following parameters can be set: relay switch output control, temperature alarm threshold, relay usage and alarm setting, query of DIP switch status, etc.

Private line

Both communication parties are connected permanently.

Protection strategy

In case the service route provides multiple service protections, different protection strategies can be selected as required. Protection strategy refers to the protection mode given the priority in use for the trail: protection, no protection, and extra traffic. Of the above, the protection preference is divided into trail protection and sub-network connection protection.

Protection sub-network

In the , the protection sub-network becomes a concept of network level other than multiplex section rings or path protection ringsin the original NES or RMS+ NM. The protection sub-network involves NEs and fiber/cable connections. In other words, the resources that form a protection sub-network include NEs and fiber/cable. Only after the NE is created, the basic configurations for the NE is done and the fiber & cable connections among NEs are correctly set up, enough resources can be available for the creation of a protection sub-network. These are the preconditions for creating a protection sub-network. From the viewpoint of logical system, the creation of the protection sub-network actually means that corresponding logical system is configured for each NE by means of creating the protection sub-network, the optical interfaces (or VC4) of each board are mapped into the logical system, and then these independent logical systems are connected with one another to form a complete network structure.

Protocol controller status

Start or stop status of the protocol controller of the protection sub-network, including such statuses as not started, protocol start, protocol is starting, part start.

Prototype trail

The prototype trail is the server layer trail, and those listed are all server layer trails that satisfy the source/sink and board conditions. If the centralized route has been selected in the first step, only one prototype trail needs to be selected here. The system will automatically find out other trails whose routes are consistent with the selected prototype trail, and If the amount found can not meet the bandwidth requirement, the system will automatically copy the prototype trail. If the separated route has been selected in the first step, prototype trails as many as the number of bandwidths should be selected.