G.703 E1 2048kbit/s
The G.703, E1, 2048kbit/s unbalanced, (75 Ohm BNC), ports are intended to
connect to, for example, a leased telecom line.
21-219
There are two C37.94 fiber optic ports that are multiplexed into one E1-protocol.
“Channel 0” is inserted/extracted in timeslot 1 – 13 in the E1-protocol.
“Channel 1” is inserted/extracted in timeslot 17 – 29 in the E1-protocol.
E1 timeslot 0 contains framing/synchronization information. Timeslots 14, 15, 16, 30
and 31 are ignored at receive and set to 0 at transmit.
In the IEEE C37.94 protocol each data bit is followed by its complement. Only
“true”, (non complement), data bits are transferred to E1-protocol.
The N is fetched from the IEEE C97.94 protocol indicating the number of timeslots
used in the protocol.
The 21-219 transfer the N-value but don’t use it for any other purpose.
All data bits in all 12 timeslots are transferred, regardless of the value of N.
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