Ericsson LBI-39224 manual T1/E1 Digital Site Configuration

LBI-39224

depending upon board configuration, can provide modem-less data links over spare T1/E1 channels to either internal or external devices. Some, all, or none of these ports can be utilized depending on board configuration. Five of the subrate ports support synchronous or asynchronous data links and the remaining three are synchronous-only ports.

T1/E1 Digital Site Configuration

Networked Systems Considerations

Any system nodes that are connected using T1/E1 Interfaces must remain frequency locked at all times. The T1/E1 Interface design allows for total network synchronization by offering the following CEC/IMC Configuration options. Each of these options are selectable by configuration of both the Clock Boards and the T1/E1 Interface Cards.

1.Master - Redundant Clock Circuits generated by the Clock Board in a FREE RUN mode. This allows any CEC/IMC to become the master source of Network timing. All nodes connected to this CEC/IMC will be in the slave mode. This mode is established by setting the Clock Board DIP switches to "Master" mode and all the T1/E1 Interface Cards' Slave Clock option to "NONE."

2.T1/E1 Slave - Redundant Clock Circuits generated by the Clock Board synchronized to 1 (or 2 with redundancy) T1/E1 Interface into the CEC/IMC. The CEC/IMC can be slaved to an external node that is connected through a T1/E1 link, and no additional timing source is needed. Timing from the T1/E1 line is passed to the Clock Board from the T1/E1 Interface Cards through a redundant set of synchronization clocks named Slave A and Slave B. Each T1/E1 Interface Card can provide Slave A, B or A&B. This mode is established by setting the Clock Board DIP switches to "Slave to 8kHz" and 1 T1/E1 Interface Card Slave Clock option set to "SLAVE A," with another set to "SLAVE B" for redundancy, or 1 T1/E1 Interface Card set to "SLAVE A&B" for no redundancy.

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