Glossary T

Tag/UnTag

The Ethernet port that can recognize and send the packet with a 802. 1Q tag header is called a Tag port; otherwise it is called an UnTag port. The port set as Tag can only recognize the packet with a 802. 1Q tab header and will discard the packet without a 802. 1Q tag header. The port set as UnTag processes the packet as an ordinary packet. Packets either with or without a 802. 1Q tag headerscan pass through the port. For the packet with a 802. 1Q tag header sent from the port, the UnTag port will remove its 802. 1Q tag header, thus the packet with a 802. 1Q tag header is converted into an ordinary packet.

TDA board service

The TDA board can be configured with 1 - 12 two/four-wire audio interfaces (the rate is 64 kbit/s), or with 4 RS-232 and 4 RS-422 data interfaces (the maximum rate is 19. 2kbit/s). The service added/dropped to/from these interfaces correspond to the time slots 1 - 20 of the NMS "Local 2M" (12 audio interfaces correspond to time slots 1 - 12 respectively, 4 RS-232s correspond to time slots 13 - 16 respectively and 4 RS-422s correspond to time slots 17 - 20). The TDA board occupies at least one 1 2Mbit/s, or at most 4 2Mbit/s (corresponding to 2M-1, 2M-2, 2M-3 and 2M-4 in the NMS). The corresponding time slot range of each 2M-1, 2M-2, 2M-3 and 2M-4 is 1-31. All TDA boards in the whole network can share 1 - 4 2Mbit/s, i. e. the whole network occupies 1 - 4 2Mbit/s altogether. In order to send these tone signals and digital signals to the SDH network for transmission, it is necessary to cross-connect the local 2M (20 64 kbit/s payloads) and four 2M signals (2M-1, 2M-2, 2M-3 and 2M-4) added/dropped from the XCS- board.

TDA clock source

TDA is short for Tone Data Access. For the 2500+ NE equipment, it can be installed with the external TDA board for which the clock source must be set so that the TDA board can switch according to the set clock source sequence when clock source switching occurs.

TDA feeding selection

It can be selected whether the audio port of the SS42TDA board is in feeding mode or non-feeding mode. When the feeding mode is selected, two lines have -48V DC feeding. After the telephone set is connected and the audio service configured, the user can make a phone call without dialing. Generally, the feeding mode is configured during test so as to connect the telephone set for test. When the non-feeding mode is selected, the non-feeding terminal (MODEM, for example) can be connected to transmit services.

Time of charging data circuit deactivation

If the circuit is active at the moment when the charging time zone ends, this moment is the time of deactivating the charging data circuit. Otherwise, it is the general time of circuit deactivation.

Time of data circuit activation

If the circuit is active at the moment when the charging time zone starts, this moment is the time of activating the charging data circuit. Otherwise, it is the general time of circuit activation.

Topology

The U2000 Web LCT topology is a basic component of the man-machine interactive interface. The topology clearly shows the structure of the network, the alarms of different NEs, sub-networks in the network, the communication status as well as the basic network operation status.

Traffic frame discard flag

It is the traffic frame discard control. Two options are provided: enable and disable. It indicates the means by which the NE discards cells when the network is congested. When the frame discard mark is closed, the cells will be discarded at the cell level; when it is opened, they will be discarded at the frame level. Here, "frame" refers to the AAL protocol data unit.

Trail

A trail is a kind of transport entity, mainly engaged in transferring messages from the input of the trail source to the output of the trail sink, and monitoring the integrality of the transferred messages. According to the different levels of the trail, the trail includes various types (OTS, OCH, OMS, SPI, RS, MS, VC4 server trail, VC4, VC3 and VC12). Among them, OTS, OCH and OMS represent the trails in a DWDM layer network. For the ADM and TM equipment in the SDH network, each optical fiber connection corresponds to an SPI, RS or MS trail, and a trail is the general name for service carriers, including SDH and PDH services.

Trail consistency check

Check whether the circuit route and the activation status of the NMS side and NE side are the same, clear the superfluous MOs and combine some of the circuits. During network expansion, such an operation as adding fibers to the SDH NNI or configuring/deleting services through the configuration layer will result in circuit inconsistency.

Transmission media layer route

It refers to the physical media such as optical fibers and NEs passed by the trail.

Tributary loopback

A fault can be located for each service path by performing loopback to each path of the tributary board. There are three kinds of loopback modes. 1. No loopback: It is the normal status. No loopback is needed when the equipment runs efficiently; 2. Outloop: When arriving at the line board after passing the input port in the local NE, the input signal is directly looped back to the service output end; 3. Inloop: The input signal is returned along the original trail from the tributary board of the target NE.

TU 1: N protection

TU protection is of the equipment level and it uses one standby TU to protect n TUs. When the working protected board is faulty, e. g. when board self-test fails, the board is pulled out, and the board power supply fails, etc. , the SCC will send switching command, and the payload of the protected board can be automatically switched over to the specified protection board and the work will be accomplished by the protection board. After the fault is cleared, the service will be automatically switched to the original board. Switching priority can be set for each protected board to make the switching setting more flexible. Some operations in the tributary board protection switching will trigger some abnormal events.