Charles Spurgeon (spurgeon@jessica.Stanford.EDU)
3 Jun 1988 1131-PDT (Friday)
The new Ethernet specifications. Much has changed. Much stayed the same.
Vendors like to gloss over the differences (it's a lot easier than trying to
describe them!) and you're on your own trying to figure out how it all
This standard was written to comply with the OSI model. As a result, it
contains much more jargon and can be much less understandable at first. An
explanatory guide like Stalling's volume 2 is a requirement to help the
newcomer to OSI make any sense of it all.
9. "Supplements to Carrier Sense Multiple Access with Collision Detection,
ANSI/IEEE Std 802.3a,b,c,and e-1988". ISBN 0-471-61153-0 Same access as
A set of additions to the 1985 802.3 standard, including the thin Ethernet
standard (Type 10BASE2). Also included is the broadband standard (Type
10BROAD36) and a revision of section 9 of the 1985 standard on repeaters.
-- Ethernet hardware information --
None of the Ethernet standards docs are very useful when it comes to
actually building, testing, and operating an Ethernet. For that you need
information about what topologies are allowed, how Ethernet equipment is
configured, how to attach connectors and all the rest. While there isn't a
good general book available on Ethernet design and construction, the
following manual can help.
10. "LAN Cable and Accessories Installation Manual", January 1986, published
by Hewlett-Packard Co.. HP Part No. 5955-7680. $45.00. Order from H.P.
Direct at 1-800-538-8787.
This manual is somewhat dated and contains instructions for installing thick
cable transceivers that are obsolete, for instance. On the other hand, the
network configuration information is useful and the guidelines for
routing cables and grounding issues are informative. My major disagreement
with H.P.'s grounding instructions is that they allow metallic cable between
building frames if H.P.'s surge arrestors are installed. Given the
ease of using fiber optic repeaters, and the dangers inherent in metallic
network cables that travel between building frames, there seems little
excuse for not using fiber in these situations.
In any event, the manual really shines when it comes to complete
descriptions of thick cable and thin cable wire strippers and connector
crimpers. The H.P. manual has diagrams showing how to strip each kind of
cable and how to crimp on N connectors and BNC connectors.
There's a short section on verifying the cables you've built, and a longer
section on how to use a Time Domain Reflectometer to test networks. Another
useful section is the one on how to open up a crimp tool that has been
closed on something you didn't want to crimp (like your finger!). Don't
laugh - this section came in handy the other day when a student used a crimp
tool with a 75 ohm UHF crimp die in it to crimp a 50 ohm N connector. The
instructions in the H.P. manual allowed us to get the mauled N connector out
without dismantling the whole tool and ruining the precision adjustments.
-- Access --
Aside from various phone numbers listed above, the following book stores can
be of service:
Computer Literacy Bookshop, 2590 North First St., San Jose, CA 95131. Phone
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