Configuring Dcr - Cisco NCS 4200 Series Configuration Manual

Verifying ACR Configuration
cem-group 1 unframed
e3 clock source recovered 1
ACR Global Configuration
enable
configure terminal
recovered-clock 0 4
clock recovered 1 adaptive cem 0 1
end
Verifying ACR Configuration
Use show recovered clock command to verify E1 ACR configuration:
#show recovered clock
Recovered clock status for subslot 0/16
----------------------------------------
Clock
1
(Port/au-4/tug3/tug2/e1)
Use show recovered clock command to verify T3 ACR configuration:
#show recovered clock
Recovered clock status for subslot 0/16
----------------------------------------
Clock
1

Configuring DCR

Differential Clock Recovery (DCR) is another technique used for Circuit Emulation (CEM) to recover clocks
based on the difference between PE clocks. TDM clock frequency are tuned to receive differential timing
messages from the sending end to the receiving end. A traceable clock is used at each end, which ensures the
recovered clock is not affected by packet transfer.
To configure E1 DCR:
enable
configure terminal
controller sdh 0/0/16
rate STM1
no ais-shut
alarm-report all
clock source internal
overhead s1s0 0
aug mapping au-4
au-4 1
clock source internal
mode tug-3
tug-3 1
mode vc1x
tug-2 1 payload vc12
e1 1 cem-group 1 unframed
e1 1 clock source recovered 1
tug-2 2 payload vc11
tug-2 3 payload vc11
tug-2 4 payload vc11
end
To configure E3 DCR:
enable
configure terminal
1 port OC-48/ 4 port OC-12/OC-3 + 12 port T1/E1 + 4 port T3/E3 CEM Interface Module Configuration Guide, Cisco
IOS XE Fuji 16.7.x (Cisco NCS 4200 Series)
34
Type Mode CEM
STMx-E1 ADAPTIVE 1
Type Mode CEM
STMx-E3 ADAPTIVE 1
Status Frequency Offset(ppb)
ACQUIRED n/a
Status Frequency Offset(ppb)
ACQUIRED n/a
Configuring SDH
Circuit-No
0/1/1/1/1
Circuit-No
0/1/1 (Port/au-4/tug3)