Glossary E

EMU

As one type of power and environment monitoring unit, EMU (short for Environment Monitoring Unit) is installed on the top of the OptiX 155/622H equipment cabinet 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 NMS system, the change of environment can be monitored timely and accurately.

ET1 board

The ET1 (Ethernet Transparent Transmission Unit) has eight 10M/100M standard Ethernet interfaces (in compliance with the IEEE 802. 3 recommendation). Its applications are as follows:(1) The ET1 board can map the Ethernet frames of 1 to 8 10/100Base-T ports into 1 to 48 2Ms. Where, each network port can also be mapped into 1 to 48 2Ms. The ET1 board can perform bandwidth separation and management for users in VLAN mode. In this way, different users can be differentiated in the same 10M/100M signal so as to manage the bandwidth. Besides, the VLAN-based port bandwidth sharing and statistical multiplexing can be realized. (3) As the Ethernet frames are mapped into N 2Ms (N=<48) and transmitted in the same point-to-point mode as the SDH, the protection capability of the SDH can be fully used. The board attributes include tributary loopback, path protection, path impedance, retiming work mode, SXT work mode, path service type, code pattern, path phase lock, input type equalization, to-be-sent J2, to-be-received J2, ser

Ethernet end-to-end trail

It is the MAC port to MAC port Ethernet service transparent transport trail provided by multiple SDH end-to-end trails (such as VC12, VC3, VC4, cascade service, etc).

Ethernet interface board

The processing board and wire led-out board are separated in the Ethernet interface unit. Therefore, when different interfaces are needed, if the 100M optical interface is to be used or more network interfaces are to be added for example , now it only needs to replace or add the corresponding wire led-out board. It not only saves costs for users but also facilitates the upgrade and maintenance. The ET1 board has two types of interface boards: ETF4 and EFF4. As the Ethernet service outlet board of the Ethernet transparent transmission interface unit, they have the following functions: 1. Support the access of four 10/100Base-T Ethernet services (ETF4 board); Support the port self-adaptation function; Support port full duplex and half duplex; 2. Support the access of four 100Base-FX Ethernet services (EFF4 board); Provides the single-mode/multimode optical interface; Support the automatic shutdown function of multimode optical interface.

Exercise switching

Exercise switching is used to test whether a switching protocol can work normally and no switching operation is really conducted.

Extended IP address of NE

It is the serial number of a sub-network where an NE resides, which is usually used to distinguish different network segments in a WAN. An extended ID and an ID form the physical ID of an NE.

Extended protection sub-network

It is an unprotected chain like ADM-ADM-TM or ADM-ADM-ADM. For a chain protection sub-network, the logical systems at the two ends should be configured as TM, with only the one in the middle configured as ADM. But in the process of practical engineering installation, the networking equipment at the bottom layer may arrive in different batches. Thus the part of no protection line is not available, but the service on it needs activating gradually during project building. Then, another protection sub-network is needed to support the incomplete protection sub-network. As it is can be extended, we name it extended protection sub-network. The Web LCT can support searching for it, deleting it and deleting it from network layer but creating it. When the new equipment arrive, the user should delete it from network level and search for protection sub-network and trail once more.