Illustrated TCP/IP:Comparison of Sparse- and Dense-Mode Protocols

Illustrated TCP/IP
by Matthew G. Naugle
Wiley Computer Publishing, John Wiley & Sons, Inc.
ISBN: 0471196568 Pub Date: 11/01/98

Table of Contents

Sparse Mode	Dense Mode
Requires explicit joining of senders and receivers. Does not send packets where they have not been requested.	Sends and stores explicit prune information in response to unwanted packets.
Stores shared-tree join information in anticipation of data packets.	Stateless untoll data packets are sent.
Relies on an RP initially for senders and receivers to meet and build a shared tree.	No RP, the broadcast nature of the protocol builds the tree.
Unicast protocol independent.	Unicast protocol dependent.
Requires periodic refreshing of explicit Join/Prune messages.	No periodic updates on Prune messages, event driven.

PIM-Sparse Mode is modeled after the Core-Based Tree algorithm. However, the difference between the two is that CBT uses one tree, centered at a core router, instead of at the source of a multicast datagram. CBT builds a single tree for all members in a group.

Comparison of Sparse- and Dense-Mode Protocols

Sparse Mode	Dense Mode
Requires explicit joining of senders and receivers	Sends and stores explicit prune state and receivers information in response to unwanted packets
Does not send packets where they have not been requested	Broadcasts the first multicast packet
Stores shared-tree join information in anticipation of data packets	Stateless until data packets are sent
Relies on an RP initially for senders and receivers to meet and build a shared tree	No RP, the broadcast nature of the protocol builds the tree
Unicast protocol independent	Unicast protocol dependent
Requires periodic refreshing of explicit Join/Prune messages	No periodic updates on Prune messages; event driven

Table of Contents

Chapter 290Comparison of Sparse- and Dense-Mode Protocols

Chapter 290
Comparison of Sparse- and Dense-Mode Protocols