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2 e1 framing, E1 framing, Table 9-14. e1 fas/nfas framing – Rainbow Electronics DS26519 User Manual

Page 61

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DS26519 16-Port T1/E1/J1 Transceiver

61 of 310

9.9.2 E1

Framing

The E1 framing consists of FAS, NFAS detection as shown in

Table 9-14

.

Table 9-14. E1 FAS/NFAS Framing

CRC-4

FRAME

#

TYPE

1 2 3 4 5 6 7 8

0

FAS

C1 0 0 1 1 0 1 1

1 NFAS 0

1

A Sa4 Sa5 Sa6 Sa7 Sa8

2

FAS

C2 0 0 1 1 0 1 1

3 NFAS 0

1

A Sa4 Sa5 Sa6 Sa7 Sa8

4

FAS

C3 0 0 1 1 0 1 1

5 NFAS 1

1

A Sa4 Sa5 Sa6 Sa7 Sa8

6

FAS

C4 0 0 1 1 0 1 1

7 NFAS 0

1

A Sa4 Sa5 Sa6 Sa7 Sa8

8

FAS

C1 0 0 1 1 0 1 1

9 NFAS 1

1

A Sa4 Sa5 Sa6 Sa7 Sa8

10

FAS

C2 0 0 1 1 0 1 1

11

NFAS 1

1

A Sa4 Sa5 Sa6 Sa7 Sa8

12

FAS

C3 0 0 1 1 0 1 1

13

NFAS E1 1

A Sa4 Sa5 Sa6 Sa7 Sa8

14

FAS

C4 0 0 1 1 0 1 1

15

NFAS E2 1

A Sa4 Sa5 Sa6 Sa7 Sa8

C = C bits are the CRC-4 remainder; A = alarm bits; Sa = bits for data link.