12.8.19.7 LIU Configuration via Web Interface
Output Configuration of a LIU module (Line Interface Unit):
In this menu one can select between E1 or T1 mode for the LIU outputs. The selected mode is the same for all
outputs.
T1 or E1?
T1 is a digital carrier signal that transmits the DS - 1 signal. It has a data rate of about 1.544 Mbit/second. It
contains 24 digital channels and therefore requires a device that has a digital connection.
E1 is the european equivalent to T1. T1 is the North American term whereas E1 is a European term for
digital transmission. The data rate of E1 is about 2 Mbit/second. It has 32 channels at the speed of 64
Kbit/second. 2 channels among 32 are already reserved. One channel is used for signaling while the other is
used for controlling. The difference between T1 and E1 lies in the number of channels here.
Sa Bits
ITU-T Recommendations allow for bits Sa4 to Sa8 to be used in specific point-to-point applications (e.g.
transcoder equipment) within national borders. When these bits are not used and on links crossing an interna-
tional border they should be set to 1.
The Sa4 bit may be used as a message-based data link for operation, maintenance and performance moni-
toring. The SSM Bit (Synchronization Status Message) can be selected in the Web GUI for clock quality
information. Sa4 is selected as per default.
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Date: 21st August 2019
IMS-M4000
