User`s guide

SET UP
XSRING+ SHDSL switch User’s guide ref 9018809-01 Page 59
17.4 Multicast gateway
Internet Protocol multicast is a bandwidth-conserving technology that reduces traffic by
simultaneously delivering a single stream of information to thousands of corporate recipients.
Thus, the multicast gateway must be used when
• a serial master device has to send requests to multiple slave devices;
that devices can be IP or serial devices.
• Or when an IP master device (client) has to send requests to multiple
slave devices; that devices can be IP or serial devices.
The Internet Assigned Numbers Authority (IANA) controls the assignment of IP multicast addresses.
The range of addresses from 224.0.1.0 through 238.255.255.255 are called “globally scoped
addresses”. They can be used to multicast data between organizations and across the Internet.
The range of addresses from 239.0.0.0 through 239.255.255.255 contains limited scope addresses or
administratively scoped addresses. These are defined by RFC 2365 to be constrained to a local group
or organization. Routers are typically configured with filters to prevent multicast traffic in this address
range from flowing outside an autonomous system (AS) or any user-defined domain. Within an
autonomous system or domain, the limited scope address range can be further subdivided so those
local multicast boundaries can be defined. This also allows for address reuse among these smaller
domains.
Note This address range is only for the group address or destination address of IP multicast traffic.
The source address for multicast datagrams is always the unicast source address.
To configure the multicast gateway,