tfra08c13 ETC-unknow, tfra08c13 Datasheet - Page 54

• Manufacturer Part Number: tfra08c13
• Description: Tfra08c13 Octal T1/e1 Framer
• Manufacturer: ETC-unknow

TFRA08C13 OCTAL T1/E1 Framer
Frame Formats
54
Figure 14. Receive CRC-4 Multiframe Search Algorithm for Automatic, CRC-4/Non-CRC-4 Equipment
START CRC-4 PERFORMANCE MONITORING:
ASSUME CRC-4-TO-CRC-4 INTERWORKING:
• SET E BITS ACCORDING TO ITU REC. G.704, SECTION 2.3.3.4
• CONFIRM PRIMARY BFA ASSOCIATED WITH CRC-4 MFA
• ADJUST PRIMARY BFA IF NECESSARY
• KEEP A = 0 IN OUTGOING CRC-4 DATA
Interworking as Defined by ITU (From ITU Rec. G.706, Annex B.2.2 - 1991)
YES
(continued)
IN 1 SECOND OR
OUT OF PRIMARY BFA:
IN PRIMARY BFA:
CRC-4 MFA SEARCH (ITU REC. G.706, SECTION 4.2)
COUNT > 914
• ENABLE TRAFFIC NOT TRANSMITTING AIS TO THE SYSTEM
• TRANSMIT A = 0 AND OPTIONALLY E = 0 TO THE LINE
• START 400 ms TIMER
• ENABLE PRIMARY BFA LOSS CHECKING PROCESS
• OPTIONALLY DISABLE TRAFFIC BY TRANSMITTING AIS TO THE SYSTEM
• OPTIONALLY TRANSMIT A BIT = 1 AND E BIT = 0 TO LINE
• INHIBIT INCOMING CRC-4 PERFORMANCE MONITORING
LFA = 1?
CRC-4
NO
YES
BFA SEARCH?
PRIMARY
MFA BE FOUND
CAN CRC-4
NO
IN 8 ms?
YES
CONTINUE CRC-4 PERFORMANCE MONITORING:
• SET E BITS ACCORDING TO ITU REC. G.704, SECTION 2.3.3.4
NO
ASSUME CRC-4-TO-NON-CRC-4 INTERWORKING:
• CONFIRM PRIMARY BFA
• TRANSMIT A BIT = 0 TO THE LINE INTERFACE
• TRANSMIT E BIT = 0 TO THE LINE INTERFACE
• STOP INCOMING CRC-4 PROCESSING
• INDICATE “NO CRC-4 MFA”
NO
BFA SEARCH
ELAPSED?
PARALLEL
400 ms
TIMER
?
YES
YES
Preliminary Data Sheet
NO
Lucent Technologies Inc.
Lucent Technologies Inc.
October 2000
5-3909(F).fr.3