Alcatel-Lucent OmniAccess 700, Руководство по настройке CLI

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T1 Interface Overview
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Alcatel-Lucent
Beta Beta
CLI Configuration Guide
T
HE
E
XTENDED
S
UPER
F
RAME
(ESF)
Also known as D5 frame or FE. Each extended superframe consists of 24 frames.
The ESF has four different framing types:
•
Synchronization - Bit sequence 001011 in frames 4, 8, 12, 16, 20, 24 - when
working with ESF, synchronization is achieved by checking the 6 bit-long pattern
that is created from every 4th framing bit.
•
Signaling - This mechanism is very similar to the signaling mechanism of the SF,
except that it can be used for ABCD signaling using four different bits.
•
CRC-6 - Frames 2, 6, 10, 14, 18, 22 - This mechanism provides the ability to
monitor the transmission quality of the DS1 facility. It uses every 4th bit of the
framing bits in the ESF, beginning at the second one.
•
Data Link - Frames 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23 - operates using every
second framing bit, beginning at the first frame of the ESF. These bits create a 4
Kbps data link called the Facility Data Link (FDL). This channel is used for
delivering maintenance information and supervisory control. Two kinds of
messages are carried on the FDL channel, each using a different format, namely
the Scheduled messages and the Unscheduled messages.
T1 M
ODES OF
O
PERATION
When using the T1 interfaces, several modes of operation are available. These
modes are listed below:
•
Superframe (SF): Data transferred using the SF format.
•
SF + CAS: The CAS is carried over the robbed bits of each 6th and 12th frame
detected by the SF format.
•
ESF
•
ESF + CAS
•
ESF + FDL
•
ESF + CAS/CRC/FDL.
•
CCS: Can be used in each of the framed formats by dedicating one channel
(usually TS-24) for delivering the signaling messages in a predetermined protocol.