I was recently in need of a refresher on multicast routing, so I picked up Eric Rosenberg’s A Primer of Multicast Routing (Springer Briefs in Computer Science). The overall plan of the book is excellent, starting with a basic overview of what multicast is (and does), including why multicast is more efficient than unicast for multiple receiver traffic streams, and the difference between broadcasting by flooding and the general concept of multicast. Eric builds on this foundation with a chapter on the various types of multicast trees (shared, source, and redundant), along with the accompanying math.
At this point in the book, the average reader is going to be lost in the math; in the process of explaining multicast efficiency, and the various tree types, the author works through the actual efficiency calculations and the tree creation algorithms, focusing on Steiner trees. If you pick this book up, I would encourage you to read through this stuff even if you don’t understand it, and continue moving ‘til you get to Chapter 3. The focus on math backs off, replaced by examples and operational concepts once you get past Chapter 2. I found the math work useful, kicking over some rusted gears I’ve not used in years, and helping me fill in theory details I’d never known about multicast routing.
Chapter 3, Dynamic Routing Methods, is the most useful chapter in the book. Here Eric covers IGMP, CVMRP, Multicast OSPF, Core Based Trees, and the various PIM options. A special section on Rendezvous Points is extremely helpful, as is the short section comparing the various PIMs.
Past Chapter 3 are some of the most interesting sections. The fourth chapter covers overlay multicast methods; the math attack is back again with an exploration of the efficiency of overlay and network layer multicast methods. There’s a lot of food for thought here, though, for the average designer who’s considering whether to let an application handle multicast duties, or building it into the network. The chapter on interdomain routing approaches a topic not many people ever consider, since it’s so rarely deployed, in a straightforward way, and the final chapter, on MVPNs, is a very useful overview of draft-rosen and other techniques around the intersection of VPNs and multicast.
There are a number of multicast techniques you’ve probably never heard of here to add to the scope of your theoretical knowledge of multicast, including aggregate multicast trees, Gossip based multicast, ant-based mechanisms, and network coding.
If you need a refresher, or you’re looking for a good solid overview of the entire multicast space, you’d be hard pressed to find a better book that this one.