Ericsson LBI-39224 - Manual (Page 57)

LBI-39224
3-27
Figure 14 Audio Interface Type Dialog Box
(Audio Board selected)
T1/E1 Interface option
If T1/E1 Interface Card was selected (Figure 15), a new set of option
buttons will appear.
T1 is a digital transmission facility operating at 1.544 Mbps (million
bits per second) in a full-duplex, time-division-multiplexing mode. T1
is the first level or primary rate within a digital transmission and
switching hierarchy defined by AT&T called a T Carrier System. North
America has adopted the T Carrier System as a standard for digital
transmission of voice, data, and images. Time-division multiplexing
permits the derivation of logical channels within the serial bit stream.
The CEC/IMC T1/E1 Interface will allocate twenty-four 64 kbps T1
channels.
E1 digital transmission is very similar to T1. The major difference is in
the bit rate. E1 is a digital transmission facility operating at 2.048
Mbps. The difference in bit rate allows for different channel allocation
schemes. The CEC/IMC T1/E1 Interface will allocate thirty-one 64
kbps E1 channels. E1 transmission has been adopted as the digital
transmission standard in European countries.
T1/E1 selection is performed at the CEC/IMC Manager on a CEC/IMC
wide basis. Changing the line type will cause the entire T1/E1 database
to be reset (lost) for all T1/E1 "sites." T1 or E1 selection is dependent
upon the line service coming into the CEC/IMC (T1 and E1 lines are
physically different), and as mentioned above, depends upon what part
of the world you are in. Selecting T1 or E1 should only be required
when the system is first configured, after that the current system
configuration will be indicated when the
Audio Interface Type dialog
box appears on your screen and changing line type is not necessary or
desired. Choose the
OK button and the