3com 5500-ei pwr Instruccion De Instalación

 

5 

Advantages of multicast include:  

z 

Enhanced efficiency: Multicast decreases network traffic and reduces server load and CPU load.  

z 

Optimal performance: Multicast reduces redundant traffic.  

z 

Distributive application: Multicast makes multiple-point application possible.  

The multicast technology effectively addresses the issue of point-to-multipoint data transmission. By 

enabling high-efficiency point-to-multipoint data transmission, over an IP network, multicast greatly 

saves network bandwidth and reduces network load.  

Multicast provides the following applications:  

z 

Applications of multimedia and flow media, such as Web TV, Web radio, and real-time video/audio 

conferencing.  

z 

Communication for training and cooperative operations, such as remote education.  

z 

Database and financial applications (stock), and so on.  

z 

Any point-to-multiple-point data application.  

Based on the multicast source processing modes, there are three multicast models:  

z 

Any-source multicast (ASM)  

z 

Source-filtered multicast (SFM)  

z 

Source-specific multicast (SSM)  

In the ASM model, any sender can become a multicast source and send information to a multicast 

group; numbers of receivers can join a multicast group identified by a group address and obtain 

multicast information addressed to that multicast group. In this model, receivers are not aware of the 

position of a multicast source in advance. However, they can join or leave the multicast group at any 

time. 

The SFM model is derived from the ASM model. From the view of a sender, the two models have the 

same multicast group membership architecture.  

Functionally, the SFM model is an extension of the ASM model. In the SFM model, the upper layer 

software checks the source address of received multicast packets so as to permit or deny multicast 

traffic from specific sources. Therefore, receivers can receive the multicast data from only part of the 

multicast sources. From the view of a receiver, multicast sources are not all valid: they are filtered.  

In the practical life, users may be interested in the multicast data from only certain multicast sources. 

The SSM model provides a transmission service that allows users to specify the multicast sources they 

are interested in at the client side.