ZyXEL Communications GS2210-24, Руководство пользователя

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Chapter 24 Multicast
GS2210 Series User’s Guide
189
Figure 131 MVR Net w or k Exam ple
Types of MVR Ports
I n MVR, a sour ce por t is a por t on t he Swit ch t hat can send and r eceive m ult icast t raffic in a
m ult icast VLAN w hile a r eceiver por t can only r eceive m ult icast t raffic. Once configur ed, t he Swit ch
m aint ains a for war ding t able t hat m at ches t he m ult icast st r eam t o t he associat ed m ult icast gr oup.
MVR Modes
You can set your Sw it ch t o operat e in eit her dynam ic or com pat ible m ode.
I n dynam ic m ode, t he Sw it ch sends I GMP leave and j oin r epor t s t o t he ot her m ult icast devices
( such as m ult icast r out er s or ser ver s) in t he m ult icast VLAN. This allow s t he m ult icast devices t o
updat e t he m ult icast for war ding t able t o for war d or not for war d m ult icast t raffic t o t he r eceiver
por t s.
I n com pat ible m ode, t he Sw it ch does not send any I GMP r epor t s. I n t his case, you m ust m anually
configure t he for war ding set t ings on t he m ult icast devices in t he m ult icast VLAN.
How MVR Works
The follow ing figur e show s a m ult icast t elevision exam ple w her e a subscr iber device ( such as a
com put er ) in VLAN 1 r eceives m ult icast t raffic fr om t he st r eam ing m edia ser ver, S, via t he Swit ch.
Mult iple subscr iber devices can connect t hr ough a por t configur ed as t he receiver on t he Swit ch.
When t he subscr iber select s a t elevision channel, com put er A sends an I GMP r epor t t o t he Sw it ch
t o j oin t he appr opr iat e m ult icast gr oup. I f t he I GMP r epor t m at ches one of t he configur ed MVR
m ult icast gr oup addr esses on t he Swit ch, an ent r y is cr eat ed in t he for war ding t able on t he Sw it ch.
This m aps t he subscr iber VLAN t o t he list of for war ding dest inat ions for t he specified m ult icast
t raffic.
When t he subscr iber changes t he channel or t ur ns off t he com put er, an I GMP leave m essage is sent
t o t he Swit ch t o leave t he m ult icast gr oup. The Swit ch sends a quer y t o VLAN 1 on t he r eceiver por t
( in t his case, an uplink por t on t he Sw it ch) . I f t her e is anot her subscr iber device connect ed t o t his
por t in t he sam e subscr iber VLAN, t he r eceiving por t w ill st ill be on t he list of for war ding dest inat ion
for t he m ult icast t raffic. Ot her w ise, t he Swit ch r em oves t he r eceiver por t fr om t he for war ding t able.
S
Multicast VLAN
VLAN 1
VLAN 2
VLAN 3