Interconnections

If your life is an acronym soup of protocols like IPX and CLNP, and you sometimes feel like you need a cot in the wiring closet, you probably ought to keep reading -- more so if finding a fount of information neither too abstruse nor too patronizing is important. For the networking professional, inveterate reader and reviewer Danny Yee here briefly takes on a book called Interconnections: Bridges, Routers, Switches, and Internetworking, which could be that fount.

Interconnections author Radia Perlman pages 537 publisher Addison-Wesley rating 8.5 reviewer Danny Yee ISBN 0-201-63448-1 summary Well-grounded introduction for the technically astute to the hardware which carries your data and how to communicate with it. Interconnections is aimed at computer science students studying networking: it covers fundamental concepts and basic theory, and includes a set of "homework" problems with each chapter. But it is solidly grounded in real-life experience -- Perlman has spent years designing and implementing network protocols and algorithms (most notably the spanning tree algorithm used in most bridges) and uses that experience to provide practical illustrations of the theory. She is also fun to read, being prepared to laugh at things that deserve it and to offer personal opinions, sometimes quite bluntly.

"I find BGP scary. It is configuration-intensive. Routes can be permanently unstable. It solves only whatever it happens to solve rather than providing a general-purpose solution. But we're stuck with it."

Perlman roughly follows the protocol stack upwards. Four chapters cover general data-link layer issues, transparent and source-routing bridges, the various categories of hub/switch/bridge, and VLANs. Five chapters cover the network layer cover connection-oriented protocols (X25 and ATM) and general issues, addressing, and packet formats in connectionless networks, with examples from a range of protocols including IP, IPX, IPv6, CLNP, Appletalk, and DECnet. A single chapter covers autoconfiguration and endnode issues (protocols such as ARP). And there are five chapters on routing, covering general routing concepts (distance vector and link state algorithms, link costs and types of service), implementation (algorithms for fast packet forwarding), and specific routing protocols (from RIP to BGP), as well as the more specialised topics of WAN multicast and "sabotage-proof routing."

The bulk of Interconnections may be too detailed for most network administrators or programmers, but those without an interest in the theory may want to track down a copy just for the last two chapters. "To Route, Bridge, or Switch: Is That the Question?" is a good overview of networking terminology and its connection with reality, while "Protocol Design Folklore" attempts

"to capture the tricks and 'gotchas' in protocol design learned from years of layer 2 and layer 3 protocols. Interspersed among the text are boxes containing 'real-world bad protocols.' They share with you the warped way I look at the world, which is to notice and be distracted by suboptimal protocols in everyday life."

Interconnections will do much to improve understanding of networks and network protocols: as well as being an excellent textbook, it should command a general audience among computing professionals.

Purchase this book from Fatbrain. You can read more of Danny Yee's reviews at his site.