Configuring IP Multicast Routing
Controlling the Transmission Rate to a Multicast Group
IPC-430
Cisco IOS IP Configuration Guide
A multicast static route allows you to use the configuration in Figure68 by configuring a static multicast
source. The Cisco IOS software uses the configuration information instead of the unicast routing table.
Therefore, multicast packets can use the tunnel without having unicast packets use the tunnel. Static
mroutes are local to the router they are configured on and not advertised or redistributed in any way to
any other router.
To configure a multicast static route, use the following command in global configuration mode:
Controlling the Transmission Rate to a Multicast Group
By default, there is no limit as to how fast a sender can send packets to a multicast group. To control the
rate that the sender from the source list can send to a multicast group in the group list, use the following
command in interface configuration mode:
Configuring RTP Header Compression
Real-Time Transport Protocol (RTP) is a protocol used for carrying packetized audio and video traffic
over an IP network. RTP, described in RFC 1889, is not intended for data traffic, which uses TCP or UDP.
RTP provides end-to-end network transport functions intended for applications with real-time
requirements (such as audio, video, or simulation data over multicast or unicast network services).
The minimal 12 bytes of the RTP header, combined with 20 bytes of IP header and 8 bytes of UDP
header, create a 40-byte IP/UDP/RTP header, as shown in Figure70. The RTP packet has a payload of
approximately 20 to 150bytes for audio applications that use compressed payloads. It is very inefficient
to send the IP/UDP/RTP header without compressing it.
Command Purpose
Router(config)# ip mroute source-address mask
[protocol as-number] {rpf-address | type number}
[distance]
Configures an IP multicast static route.
Command Purpose
Router(config-if)# ip multicast rate-limit {in |
out} [video | whiteboard] [group-list access-list]
[source-list access-list] kbps
Controls transmission rate to a multicast group.