Glossary A

Active/standby switching of cross-connect board

If there are two cross-connect boards on the SDH equipment, which are in hot back-up relation of each other, the operation reliability is improved. When both the cross-connect boards are in position, the one inserted first is in the working status. Unplug the active board, the standby one will run in the working status automatically. When the active cross-connect board fails in self-test, the board is pulled out, the board power supply fails or the board hardware operation fails, the standby cross-connect board can automatically take the place of the active one. XC1, XC4, GTC, X16, X64, XCS, TXC, DTD, AXCS and STG boards all support active/standby switching.

Add/drop wave band

A board like MB2 divides the wavelength resources into such fixed wavelength groups as 1 - 4, 5 - 8 and 9 - 12, etc. A wavelength group is called a wave band, and a wave band bearing the added/dropped services is called add/drop wave band.

Add/drop wavelength

In the OADM equipment, the boards MR2, MR3, MR4, MR8 and MB2 bear the wavelength directly adding/dropping services.

AIS insertion

If there are excessive errors in a channel, AIS is inserted in this channel to indicate it is unavailable. For a line board, it can be set whether to insert AIS when there are excessive errors in the B1, B2 and B3 bytes. For tributary board at the E1/T1 level, it can be set whether to insert AIS when there are excessive errors in BIP-2. For tributary board at the E3 level or higher, it can be set whether to insert AIS when there are excessive errors in the B3 byte.

Alarm correlation analysis

In case alarm2 is generated within five seconds after alarm1 is generated, and it complies with the conditions defined in the alarm correlation analysis rule, you can either mask the alarm or raise the level of alarm2 according to the behavior defined in the alarm correlation rule. Such a process is called alarm correlation analysis.

Alarm correlation rules

It refers to the rule of processing alarm1 and alarm2 under certain conditions. Such conditions are supported as follows:(1) Alarm1 and alarm2 occur on the same object; (2) Alarm1 occurs in the service upstream of alarm2; (3) Alarm1 occurs at the opposite service end of alarm2. The following actions are supported at present:(1) Alarm1 masks alarm2; (2) Raise the level of alarm2The alarm correlation rule is the basis for alarm correlation analysis, which affects the result of alarm correlation analysis. Set it with caution.

Alarm hold-off time

Alarm delay includes starting delay and stopping delay. An alarm is not regarded as being generated until the NE has been detecting it for a period of time, and this period of time is the alarm start hold-off time; An alarm is not regarded as being ended until the NE has been detecting the ending of it for a period of time, and this period of time is the alarm end hold-off time; Setting the hold-off time can avoid the generation of unnecessary alarms due to misreport or jitter.

Alarm filter

Alarms are detected and reported to the NM system, and whether the alarm information is displayed and saved is decided by the status of the alarm filter. An alarm with the filtering status set to "Filter" is not displayed and saved on the NM, but is monitored on the NE.

Alarm indication

On the cabinet of an NE, there are three indicators with different colors indicating the current status of the NE: Green indicator on: The NE is powered on; Red indicator on: A critical alarm is generated; Orange indicator on: A general alarm is generated. You can stop the NE alarm indication through the NM.

Alarm inversion

The alarm report condition of the NE port is related to the alarm inverse mode (not inverse, automatic recovery and manual recovery) setting of the NE and the alarm inversion status (Enable and Disable) setting of the port. When the alarm inversion mode of NE is set to no inversion, alarms of the port will be reported as usual no matter whatever the inversion status of the port is. When the alarm inversion mode of the NE is set to automatic recovery, and the alarm inversion state of the port is set to Enabled, then the alarm of the port will be suppressed. The alarm inversion status of the port will automatically recover to "not inverse" after the alarm ends. For the port that has already been configured but not actually loaded with services, this function can be used to avoid generating relevant alarm information, thus preventing alarm interference. When the alarm inverse mode of the NE is set as "not automatic recovery", if the alarm inversion status of the port is set as Enable, the alarm of the port will be

Alarm inversion mode

After the service is accessed or the fault is removed, whether the port is automatically restored to the normal status depends on the alarm inversion mode of this NE. There are three alarm inversion modes: normal, revertible and non-revertible. (1) Automatic restoration mode: If the NE alarm inversion mode is set to automatic restoration, after the NE port set to the inversion status accesses services or the fault is removed, it will be restored to the normal status automatically and an event is reported; (2) Manual restoration mode: If the NE alarm inversion mode is set to manual restoration, after the NE port set to the inversion status accesses services or the fault is removed, it will not be restored to the normal status automatically and manual restoration is required; (3) Not-to-invert mode: If the NE alarm inversion mode is set to not-to-invert, how the inversion status of the NE port is set will not affect alarm reporting of this port.

Alarm level

According to ITU-T recommendations, the alarm is classified into four levels:

Critical: Services have been affected, and correct recovery measures should be taken immediately. Major: Services have been affected, and correct recovery measures should be taken in time.

Minor: Services have been affected, and measures should be taken to avoid severer fault.

Warning: A potential fault that may affect services is detected, and measures should be taken for further diagnosis (if necessary) and correction.

Alarm level

There are six alarm types as following: Communication: alarm indication related with information transfer

Processing: alarm indication related with software or information processing

Equipment: alarm indication related with equipment fault

Service: alarm indication related with QoS of the equipment

Environment: alarm related with the environment where the equipment resides, usually generated by a sensor

Security: alarm indication related with security

Alarm mask

Alarm mask means not monitoring the alarm event of a specific object. The object here may be the networkwide equipment, a specific NE, a specific board and even a specific functional module of a specific board.

Alarm storing mode

There are two modes for saving alarms: stop and wrap. Under stop mode, new alarms will be discarded when the alarm register in NE is full. Under wrap mode, the earliest alarms will be deleted and new alarms will always be saved when the alarm register in NE is full.

ALC link

The ALC link is a piece of end-to-end configuration information, which exists in the equipment (single station) as an ALC link node. Via the ALC function of each node, it fulfills optical power control on the line that contains the link.

ALC node

ALC functional unit, which corresponds to the equipment, achieves the ALC function through the coordination among the VOA, WBA, SC1/SC2 and MS2 boards.

ATM protection group

It refers to the logically bound ATM VP network/sub-network connections that share the same physical transmission channel. In the VP Group (VPG), a pair of VP connections (working connection and its protective connection) is used for monitoring the automatic protection switching, called monitoring connections (APS VPCs). If the monitoring connections switch over, the whole VPG will switch over to quicken the ATM protection switching (as quick as the protection switching of the SDH layer).

Automatic alarm report

Report the alarm to the NM as soon as it is generated at the equipment side. The NM pops up the alarm panel. The user can view this alarm information in the alarm panel without active query.

Automatic alarm synchronization

The can automatically acknowledge all unacknowledged alarms before the specified days at 3:00 AM every day. The ended alarm that has been acknowledged will become the history alarm. The user in the acknowledgement information is "Automatic Acknowledgment".

Automatic laser shutdown

Automatic laser shutdown means that automatic laser shutdown is permitted when the optical interface board does not bear services or the optical fiber is faulty. Its service life can be prolonged by decreasing the on time of the laser. In shutdown period, the laser will start automatically every other a period of time (off time) to test whether the line is normal. In the laser shutdown period, the test function can be manually started immediately (by clicking <Test>) without the off time. The will test whether the service over the fiber is restored to normal. If yes, the laser will be turned on again and starts working normally. If no, the laser will be shut down again after continuous light emitting after a certain period of time (continuously on time). The on and off time of the laser during automatic test can be set on the .

Automatic switching

When a fault occurs to the line, the line board will detect SD (signal deterioration) or SF (signal failure) condition and then report it to the SCC board that will generate K byte and send it out via the line board according to APS protocol. The line boards of other nodes will report it to the SCC board after receiving K byte. Finally SCC board will specify the switching status of the node according to protocol, and send command to XCS board to perform the switching of payloads. Fault restoration. After switching restoration time, this protection sub-network will switch to the working route and resume normal working status.

Auto-negotiation

The rate/work mode of the communication party set as self-negotiation is specified through negotiation according to the transmission rate of the opposite party.