思科CMTS負(fù)載均衡

CMTSLoadBalanceOverviewBy

Zhimin

ZhangHowLBusually

workEach

LBG

contains

some

DS/US

channel.When

modem

is

registered,

it

will

be

assigned

to

a

LBG

(

except

legacy

LBG.)CMTS

check

the

balance

status

periodically,

if

not

balanced,

move

some

modem

to

lower

load

channel.HowtomeasurebalancestatusModem

countWhether

modem

number

is

balanced

across

channels.Utilization

Whether

traffic

load

is

balanced.Service

flow(notsupportanymore)Whether

service

flow

number

is

balanced.The

load

is

counted

base

on

channel,

not

only

within

LBG.“show

cable

load

load”Modemmovestrategy

(When

and

how

many

times

to

move)StaticLBMove

modem

once

after

registeredDynamic

LBMove

modem

whenever

not

balanced.Passive

LBCMTS

ignore

the

register

for

modem

on

overload

channelHowtomovemodem

(message

send

to

modem)DCCMove

primary

DSDBCMove

both

primary

and

bonding

group.UCCMove

upstream

onlyInit

tech

0-4,

configurable.LBTypesLegacyLoadBalancing(Notsupportedinnewrelease)Can’tdifferentiateindividualmodemDocsisLoadBalancingD2.0GLBG(D2.0modems)D3.0GLBG(D3.0modems)RLBG(both2.0/3.0)Modem

will

be

assigned

to

a

load

balance

group

to

take

effect.“show

cable

load-balance”HowtocreateLBG2.0GLBG/RLBGusethesamecommand,butRLBGhasarestrictkeywordcableload-balancedocsis-group1restricted

downstreamModular-Cable7/1/0rf-channel0-7upstreamCable7/1/00-33.0

GLBG

are

created

automatically

when

FN

is

created.

Can’t

be

created

by

CLI,

but

parameter

can

be

changed.LegacyLoadBalancingCiscoprivatesolution.Not

process

each

individual

modem

after

registered.No

LBG

assignment.DocsisLB–

AssignmentRLBG

has

the

highest

priorityIf

a

modem

does

not

match

the

RLBG,

then

it

will

be

assigned

to

GLBG

base

on

DOCSIS

version

and

channel

set.2.0

modem

is

assigned

to

2.0

GLBG.3.0

modem

is

assigned

to

3.0

GLBG.RLBG

can

match

tagging,

oui,

docsis-version,

service

type,

cliGLBG

are

assigned

by

channel

set.To

save

the

system

resourceSince

there

may

be

tens

of

thousands

of

modems.LB

will

not

move

modem

in

real

time,

it

will

check

the

balance

status

after

every

specific

interval.Default

30s.“interval”.Toreduceping-pongeffect(flap)In

a

platform

with

unstable

modems

offline/online,

cmts

will

always

found

it’s

un-balanced

and

try

to

move

modem.Traffic

statistics

has

a

delay,

so

CMTS

may

move

to

many

modems

to

another

channel

and

have

to

move

it

back

in

next

interval.Threshold

is

used

to

accept

somewhat

un-balance.

So

that

it

will

not

waste

unnecessary

resource.“threshold”Treatvoice/videodifferentBy

default,

modem

that

has

special

service

will

not

be

moved

by

LB.

But

this

can

be

changed

by

“policy”

command.Thisistoensuretheservicequality.“policy”Wedon’twantaspecificmodemto

bemovedExclude

command“docsis-policy”

could

be

used

to

disable

a

modem

being

moved

permanently

or

for

some

period.“docsis-policy”ContinueFor

utilization

based,

move

a

modem

that

with

high

traffic

will

be

more

efficient

because

less

modem

needs

to

be

moved.But

if

the

traffic

is

very

high,

such

as

75%

of

a

channel,

then

better

not

to

move

it,

because

it

may

make

other

channel

overload

as

well.“disable-throughput-lowerbound”

to

define

what

is

high

load

modem.Upperbound

not

support

yet.WemaywantsomemodemsmovedfirstSome

modem

may

have

some

important

service,

so

if

possible,

move

other

modems

first.LB

priority

in

modem

config

file.DynamicD3.0LBCurrently

support

static/dynamic

LB

for

NB

modems.Currently

support

static

LB

for

WB/UB

modems.Now

we

are

trying

to

support

dynamic

LB

for

WB/UB

modems.AlotofexceptionforLBCase1：Channel-1has15%traffic,channel-2

has

1

percent,

threshold

is

1%.

Modem

wi