Next: Coding and Compression
Previous: Calling down traffic on
In this chapter we have looked at multi-destination packet delivery
services, for circuit, and packet, and packet over circuit based
networks. We have looked at the various routing systems that are used
to devise delivery trees over which multimedia data can be sent for
the purposes of group communication.
The main lessons are that:
- If you have group communication, network support through multicast
will in general reduce traffic significantly.
- The IP multicast model is very powerful, and is much more convenient
than the point-multipoint VC services in other networks. It is however
hard to implement the former over the latter, efficiently.
- Large scale use of multicast may require some form of aggregation of
IP level multicast tree indices (state in Mbone routers) - we do not
know how to do this at all.
- Policy and QoS support in multicast routing are not
yet available technologies.
In the next chapter, we will look at how to reduce the amount of data
that is sent so that it doesn't swamp our network.