| description |
We present a delay analysis of three generic classes of multicast
transport protocols. The first class considered is an unreliable
scheme that works without retransmission of messages. This class
also includes forward error correction approaches. The second class
uses a positive acknowledgment and retransmission scheme to
guarantee reliability. Finally, the third class is a hierarchical
approach to avoid the well-known ACK implosion problem for large
receiver groups. Our results show that only the unreliable and the
hierarchical protocol class provide scalability for large receiver
groups. For delay sensitive applications we can conclude from the
results that in case of low packet loss probabilities, reliable
multicast protocols provide low average delays, which are only
slightly increased compared to unreliable protocols. However, if we
take the maximum delay, the delay is significantly increased.
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