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Pragmatic General Multicast (PGM) provides reliable, duplicate-free delivery of data packets while reducing network congestion. PGM guarantees that receivers either receive all data packets from transmissions and retransmissions, or can detect unrecoverable data packet loss. PGM is particularly well suited to `push' applications with relatively small information transfers such as stock and news updates. For more information about PGM concepts and terminology, refer to Configuring IP Multicast Routing Protocols.
The 8000 Series switches implement the network element portion of PGM. They support the following PGM options:
The 8000 Series switch cannot serve as a DLR (designated local repairer)
because DLRs require a large amount of buffering. Therefore, the null negative acknowledgement (NNAK) parameters in Device Manager are not supported.