Ideal HFC Plant Configuration Issues
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JUNOSg 3.0 G10 CMTS Hardware Guide
154
8.
You can compute the approximate upstream channel utilization by dividing the
measured bandwidth calculated in step 5 by the derated maximum bandwidth
calculated in step 7: (4,384,549 / 4,710,400)=93 percent. This represents a highly
utilized interface.
Congestion might be attributed to one or more of the following:
!
An excessive number of cable modems are attached to a DOCSIS Module in the
return path of the HFC plant. Review your corporate guidelines to ensure you have
not exceeded the maximum number of cable modems per DOCSIS Module for the
modulation profiles being used. If necessary, install additional DOCSIS Modules.
!
An excessive number of cable modems are assigned to the upstream interface in
which the cable modem transmits. Issue the
show cable modem
command as
follows to determine the number of cable modems within an upstream interface:
user@host>
show cable modem summary total interface
cu-
virtual-slot
/
docsis-slot
/
upstream-interface
---Cable Modem Operational States---
Interface Us CM Dstry Dclr Rng Rng Rng IP Reg Access
Qty Abort Compl Compl Denied
ca-0/2/0 0 5 0 0 0 5 0 0 0 0
total 5 0 0 0 5 0 0 0 0
An excessive number of cable modems on an upstream interface can be addressed
by the following:
!
Enable load balancing in the CMTS by including the
load-balance
statement at
the [
edit services cable upstream
] hierarchy level. The CMTS attempts to
assign a cable modem to an upstream channel based on channel width and
utilization.
!
Provision one or more additional upstream interfaces in the cable interface in
which the cable modem resides. The logical allocation of up to 16 upstream
interfaces to any of the upstream ports on a DOCSIS Module allows you to
provision interfaces without the need for physical node recombining.
!
Increase the upstream channel width.
!
The cable modem is transmitting using QPSK modulation. The all-digital processing of
the Broadband Cable Processor ASIC, along with its advanced noise cancellation and
equalization algorithms, might allow the cable modems on an upstream channel to
operate at 16QAM. To change the modulation of an upstream channel, assign a new
modulation profile to that channel.
Содержание G10 CMTS
Страница 8: ... JUNOSg 3 0 G10 CMTS Hardware Guide viii ...
Страница 18: ... JUNOSg 3 0 G10 CMTS Hardware Guide 2 ...
Страница 34: ...G10 CMTS Hardware Overview JUNOSg 3 0 G10 CMTS Hardware Guide 18 ...
Страница 46: ...DOCSIS Module JUNOSg 3 0 G10 CMTS Hardware Guide 30 Figure 12 DOCSIS Module Front Panel HotSwap ...
Страница 55: ... Hardware Component Overview Chassis Control Module 39 Figure 15 Chassis Control Module Front Panel Eth0 ...
Страница 72: ...Chassis Rear Modules JUNOSg 3 0 G10 CMTS Hardware Guide 56 Figure 21 Hard Disk Module Rear Panel C O M Eth ...
Страница 82: ... JUNOSg 3 0 G10 CMTS Hardware Guide 66 ...
Страница 112: ...Rack Mounting JUNOSg 3 0 G10 CMTS Hardware Guide 96 Figure 25 Air Flow Through Chassis ...
Страница 116: ...Rack Mounting JUNOSg 3 0 G10 CMTS Hardware Guide 100 Figure 29 Rack Fully Populated with Three G10 CMTS Chassis ...
Страница 118: ...Install Power Supplies JUNOSg 3 0 G10 CMTS Hardware Guide 102 Figure 30 Power Supply Installation 1 2 ...
Страница 138: ...Connect to Power Sources JUNOSg 3 0 G10 CMTS Hardware Guide 122 Figure 39 DC Power Transition Module ...
Страница 148: ... JUNOSg 3 0 G10 CMTS Hardware Guide 132 ...
Страница 156: ...Upstream RF Measurement JUNOSg 3 0 G10 CMTS Hardware Guide 140 ...
Страница 188: ... JUNOSg 3 0 G10 CMTS Hardware Guide 172 ...
Страница 196: ...Radio Frequency RF Specifications JUNOSg 3 0 G10 CMTS Hardware Guide 180 ...
Страница 202: ...EIA Channel Plans JUNOSg 3 0 G10 CMTS Hardware Guide 186 ...
Страница 203: ... 187 Part 5 Index Index on page 189 ...
Страница 204: ... JUNOSg 3 0 G10 CMTS Hardware Guide 188 ...
Страница 209: ... Index 193 Index V ventilation 69 89 95 101 124 161 162 167 video servers 7 voltage power supply 27 ...
Страница 210: ... Index JUNOSg 3 0 G10 CMTS Hardware Guide 194 ...