tfra08c13 ETC-unknow, tfra08c13 Datasheet - Page 52

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

TFRA08C13 OCTAL T1/E1 Framer
Frame Formats
52
ASSUME CRC-4 MULTIFRAME ALIGNMENT:
• CONFIRM PRIMARY BFA ASSOCIATED WITH CRC-4 MFA
• ADJUST PRIMARY BFA IF NECESSARY
START CRC-4 PERFORMANCE MONITORING:
• SET E BITS ACCORDING TO ITU REC. G.704, SECTION 2.3.3.4
Figure 13. Receive CRC-4 Multiframe Search Algorithm Using the 100 ms Internal Timer
YES
CRC-4 MFA SEARCH (ITU REC. G.706, SECTION 4.2 - NOTE 2 )
IS 100 ms TRX = 1
IN 1 SECOND OR
YES
OUT OF PRIMARY BFA:
IN PRIMARY BFA:
COUNT > 914
• ENABLE TRAFFIC TO THE SYSTEM
• TRANSMIT A = 0 AND OPTIONALLY E = 0 TO THE LINE
• START 8 ms AND 100 ms TIMERS
• ENABLE PRIMARY BFA LOSS CHECKING PROCESS
• OPTIONALLY DISABLE TRAFFIC BY TRANSMITTING AIS TO THE SYSTEM
• OPTIONALLY TRANSMIT A = 1 AND E = 0 TO LINE
• INHIBIT INCOMING CRC-4 PERFORMANCE MONITORING
(continued)
LFA = 1?
CRC-4
?
NO
NO
MFA BE FOUND
CAN CRC-4
IN 8 ms?
BFA SEARCH?
PRIMARY
YES
SET INTERNAL 100 ms TIMER EXPIRATION STATUS BIT TO 0:
NO
• IF TRANSMITTING A BIT = 1 TO THE LINE INTERFACE, TRANSMIT A BIT = 0
• IF TRANSMITTING AIS TO THE SYSTEM INTERFACE, ENABLE DATA
• IF TRANSMITTING E = 0 TO THE LINE INTERFACE, TRANSMIT E BIT = 1
TRANSMISSION TO THE SYSTEM INTERFACE
YES
NO
CONTINUE CRC-4 PERFORMANCE MONITORING:
• SET E BITS ACCORDING TO ITU REC. G.704, SECTION 2.3.3.4
100 ms TRX = 1
INTERNAL
IS
?
YES
SET 100 ms TIMER EXPIRATION STATUS BIT TO THE 1 STATE:
SET INTERNAL 100 ms TIMER EXPIRATION STATUS BIT TO 1:
• OPTIONALLY TRANSMIT A BIT = 1 TO THE LINE INTERFACE FOR
• OPTIONALLY TRANSMIT AIS TO THE SYSTEM INTERFACE FOR THE
• OPTIONALLY TRANSMIT E BIT = 0 TO THE LINE INTERFACE FOR
THE DURATION OF LTS0MFA = 1
DURATION OF LTS0MFA = 1
THE DURATION OF LTSOMFA = 1
NO
NO
BFA SEARCH
PARALLEL
ELAPSED?
GOOD?
100 ms
TIMER
YES
YES
NO
Preliminary Data Sheet
Lucent Technologies Inc.
Lucent Technologies Inc.
October 2000
5-3909(F).er.2