Cisco Cisco RF Gateway 1
7020535 Rev A
5
Operational Enhancements
Operational Enhancements
The following features have been added between 3.00.18 and 3.01.01 and are also
included in 3.01.06.
included in 3.01.06.
Exponential Back-off of Multicast Source Switching. In 3.00.18, when a
multicast stream stops arriving from the current source IP address, the RF
Gateway 1 immediately switches to the next source. The RF Gateway 1 then
waits for 1 second on that new source IP address before switching to the next
source. Every subsequent second, another source switch is performed until
the stream recovers.
In Software Release 3.00.20 (and in 3.01.0X), an exponential back-off
algorithm for the IGMP source switching was implemented to prevent the
upstream switch or router from getting flooded with IGMP messages in cases
of stream outage. In this algorithm, the RF Gateway 1 still switches
immediately to the next source on the initial loss of input program, but it
now waits 3 to 6 seconds for the stream to arrive from the new source before
switching sources again. The RF Gateway 1 continues to use this 3 to 6
second wait time until all sources of the stream have been attempted. At that
point, the RF Gateway 1 wraps back to the original source and doubles its
wait time to 6 to 12 seconds. If the input does not recover, the RF Gateway 1
continues doubling its wait time on a source switch up to the maximum of 24
to 48 seconds.
The new algorithm also has a random element to the wait times, hence the
time ranges above. Each RF Gateway 1 on start-up calculates a random
multiplier to use when calculating the back-off time. Thus, a group of RF
Gateways connected to the same switch or router will spread their source
switches over the timeout range to ease the spike of IGMP messages received
by the switch.
multicast stream stops arriving from the current source IP address, the RF
Gateway 1 immediately switches to the next source. The RF Gateway 1 then
waits for 1 second on that new source IP address before switching to the next
source. Every subsequent second, another source switch is performed until
the stream recovers.
In Software Release 3.00.20 (and in 3.01.0X), an exponential back-off
algorithm for the IGMP source switching was implemented to prevent the
upstream switch or router from getting flooded with IGMP messages in cases
of stream outage. In this algorithm, the RF Gateway 1 still switches
immediately to the next source on the initial loss of input program, but it
now waits 3 to 6 seconds for the stream to arrive from the new source before
switching sources again. The RF Gateway 1 continues to use this 3 to 6
second wait time until all sources of the stream have been attempted. At that
point, the RF Gateway 1 wraps back to the original source and doubles its
wait time to 6 to 12 seconds. If the input does not recover, the RF Gateway 1
continues doubling its wait time on a source switch up to the maximum of 24
to 48 seconds.
The new algorithm also has a random element to the wait times, hence the
time ranges above. Each RF Gateway 1 on start-up calculates a random
multiplier to use when calculating the back-off time. Thus, a group of RF
Gateways connected to the same switch or router will spread their source
switches over the timeout range to ease the spike of IGMP messages received
by the switch.
IGMP Report Bundling. This release of the RF Gateway 1 now bundles up to
120 IGMP group records into one IP packet upstream. The previous code
would only send a maximum of 2 group records into a packet. This bundling
drastically reduces the number of upstream IP packets in response to an
IGMP general query, or in the case of a network outage causing many input
streams to fail simultaneously.
120 IGMP group records into one IP packet upstream. The previous code
would only send a maximum of 2 group records into a packet. This bundling
drastically reduces the number of upstream IP packets in response to an
IGMP general query, or in the case of a network outage causing many input
streams to fail simultaneously.
Support for 12 USRM RPC connections (and 3 DNCS connections). The RF
Gateway 1 now supports up to 12 simultaneous USRM RPC connections and
can also support up to 3 DNCS RPC connections.
Gateway 1 now supports up to 12 simultaneous USRM RPC connections and
can also support up to 3 DNCS RPC connections.