Operation Manual

AT-RG213 Residential VoIP Gateway - SIP Software Reference Manual

SIP Software Release 6-0-0

J613-M0524-00

Short Syntax

S IP IGMP [QI=1..65535] [LT=0..65535] [TO=1..65535]

Description

This command sets operational timers for IGMP.

The default values for these timers will suit most networks. Changing them

to inappropriate values can cause IGMP to function in undesirable ways. A

system administrator should only change these timer values based on a

sound understanding of their interaction with other devices in the network.

The QUERYINTERVAL parameter specifies the time interval, in seconds, at

which IGMP Host Membership Queries are sent . The default is 125.

The LEAVETIME parameter sets the duration of the Leave Period timer for

the IGMP proxy application in deciseconds. The timer controls the

maximum allowed time before hosts send a response to Query message

issue by proxy router.

In Proxy Router application when a Leave message is received on a port it

will be catch and a Query message is sent to check if other members are

present on the attached LAN. To keep valid the multicast path towards the

port a subsequent Report message must be received, otherwise the multicast

path will be purged and a Leave message will be forwarded either towards

the port where the Router was picked out or to each other ports.

The Query Response Interval (QRI) used in proxied Query message takes

values reflecting the following scenarios:

 No Multicast Routers are present - QRI will be ugual to the LEAVETIME

value.

 Multicast Routers are present - QRI will take LEAVETIME value if it has been

provisioned, otherwise it will be equal to the value read in last received Query

message.

 LEAVETIME=0 is used for fast member pruning (Fast Leaving procedure). A

received Leave message will be forward at once and the multicast path will be

cut.

The TIMEOUT parameter specifies the longest interval, in seconds, for

which a group will remain in the local multicast group database without the

router (designated router or not) receiving a Host Membership Report for

this multicast group.

All IGMP routers to maintain their group membership databases use this

TIMEOUT parameter. The default is 270. If a value is specified for

QUERYINTERVAL without specifying a value for TIMEOUT,

TIMEOUT is calculated as 2*(QUERYINTERVAL + QRI).

The QRI added

is the variation that hosts use when sending Host Membership Reports.

If a timeout interval is specified, it will override any calculated value.

Examples

To set the IGMP query interval to 180s (3 minutes), use:

SET IP IGMP QUERYINTERVAL=180