Errata sheet

For Andrew Tanenbaum, Computer Networks, 6th ed.

These are minor errata that I noticed while reading the text (the online e-book form). I have not found a page of errata from the publisher. Hopefully I am right about these being errata. This list is a work in progress. Feel free to let me know if you find any others.

• § 2.2.2 (p. 103) Last sentence should end "for preventing jamming of signals to torpedoes during war time."
• § 2.4.1 (p. 110) Equation (2-2) final right parenthesis is too large: it is one of the pair enclosing the argument of cos.
• § 2.4.2 (p. 115) At end of last sentence, “ASDL2+” should be “ADSL2+”.
• § 2.4.3 (p. 120) Middle of first paragraph under "Passband Transmission," the signal wavelength becomes large at low transmission frequencies.
• § 2.4.4 (p. 130) Start of first full paragraph on the page. (This is more of a nit-pick than an erratum.) The statement that WDM's progress "puts technology to shame" is somewhat of an overstatement. A factor of 800 increase in 29 years is a doubling about every 3 years on average. Moore's Law posits a doubling of computer performance every 2 years. If the reference is to CPU clock speeds, it is true, since those plateaued around 2004.
• § 3.1 (p. 202) Last sentence of paragraph following the numbered list, "later" should be "layer".
• § 3.2.2 (p. 217) Paragraph in mid-page starting "Consider a channel", there is an extraneous “.2” following the value “10^-10”. It should be omitted.
• § 4.2.2 (p. 277) Paragraph at top of page on p-persistent CSMA. Sentence beginning “In the latter case” has “staring again” which should be “starting again”. Also, there is a missing period at the end of the next sentence, which should go before “IEEE 802.1”.
• § 5.9, problem 34, “tried” should be “tied”.
• § 7.1.4, subsection DNS Zones (p. 626), paragraph following Figure 7-6, some domain names are incorrect. The second and third sentences should say “For example, in Fig. 7-6, the University of Chicago has a zone for uchicago.edu that handles traffic to eng.uchicago.edu. However, it does not handle cs.uchicago.edu.”