NSG 9000-6G - Harmonic Inc

Chapter 4 Configuring Applications
M-CMTS Application
1. Select Applications > M-CMTS tab:
Sessions appear in the table according to your QAM configuration in
Platform > General > Slot > QAMs. Each session appears with a unique session ID.
Session ID- Read only. A sequential number starting at 10000, to indicate the number of
the session in the current page.
NOTE: Steps 2&3 are relevant to primary DS channels only. In case of wideband sessions, move to step 4.
2. Relevant to primary DS channels only - To synchronize with the DTI time, select DTI Sync
Restamping. The EdgeQAM re-stamps the DTI sync packets.
3. Relevant to primary DS channels only - In DOCSIS Sync Compensation, enter the sync
compensation. The CMTS core router automatically inserts DOCSIS sync packets into the
primary DS QAM channels. To ensure the accuracy of the DOCSIS sync packets, the
EdgeQAM re-stamps them. Depending on RF network topology, it may be required to
fine-tune the sync messages that flow over the various QAM channels of the EdgeQAM.
The fine-tuning ensures consistent timing of CMs across all cable interfaces of the
system. To fine-tune the sync offset across cable interfaces, use the DOCSIS Sync
Compensation option. The sync offset units are ticks of the CMTS 10.24 MHz clock, where
1 tick=97.6 nano-sec. The typical allowed offset difference between modems is +/- 6
ticks. To define the sync compensation value, measure the average Cable Modem (CM)
timing offset difference (you can view the timing offset values via the CMTS console) and
calculate the desired compensation value for the QAMs of the port. Typically, the
compensation value of adjacent QAMs in the port is identical for each QAM in the port.
4. To select the input GbE Port, open the GbE Port list and select the required port. Once you
defined the required GbE port, the GbE IP Address box is updated to display the IP address
of the selected port.
5. In GbE IP Address, enter the IP address of the GbE input port.
6. In L2TP Session ID, enter the required session ID.
7. View the following Read-only information:
In RF Output, view the QAM channel to output the session where:
X – module number (1…9)
Y – RF port number (1…2)
Z – channel number (1…144)
QAM Index - see Configuring/Viewing QAM Channels on page 49.
Interleaver - see Configuring/Viewing QAM Channels on page 49.
© 2012 Harmonic Inc. 99 NSG 9000-6G, Version 2.7, Rev B