3.2.3 System configuration required for multicast distribution

(1) Standard system configuration for multicast distribution

The figure below shows the standard system configuration for implementing multicast distribution, and the flow of packets through the system.

Figure 3‒13: Standard system configuration for multicast distribution and packet flow

You need to create a multicast group for each higher system to which managed computers connect. Each of these multicast groups must be assigned a unique multicast address. The descriptions below relate to the corresponding number in the figure. 1 and 2 describe settings in the system configuration, and 3 and 4 describe the packet flow when a job is executed.

1. The group of computers that connect to relay system A is deemed multicast group A, and the group that connects to relay system B is deemed multicast group B. Assign the multicast address 239.255.0.1 to the computers in multicast group A, and the multicast address 239.255.0.2 to the computers in multicast group B.

2. Specify the multicast address of multicast group A (239.255.0.1) on relay system A, and the multicast address of multicast group B (239.255.0.2) on relay system B.

   Relay system A can now use multicast distribution to distribute jobs to the computers in multicast group A, and relay system B can use multicast distribution to distribute jobs to the computers in multicast group B.

3. On the managing server, create a job with multicast distribution specified, and execute the job.

   The managing server sends the packets for the job to each relay system. In this example, two relay systems are connected to the managing server, which means that an amount of packets equivalent to two jobs are sent. The jobs are sent to relay systems A and B by unicast distribution.

4. Relay systems A and B each send packets for just one job, regardless of the number of computers. Packets equivalent to one job flow on the common routes to each computer (multicast distribution).

Assuming the same system configuration, suppose the job were distributed using unicast distribution. In this scenario, the number of job packets flowing from the higher systems to which the managed computers are connected to the destination computers would be equivalent to the number of computers. Therefore, three times the number of packets would be sent from relay systems A and B along the routes shown in 4.

You can use multicast distribution to distribute jobs even in a configuration in which the managed computers connect directly to the managing server. In this case, you must specify the multicast address of the destination multicast group on the managing server.

To Page Top