Switching to VoIP by Theodore Wallingford This errata page lists errors outstanding in the most recent printing. If you have technical questions or error reports, you can send them to booktech@oreilly.com. Please specify the printing date of your copy. This page was updated March 26, 2007. Here's a key to the markup: [page-number]: serious technical mistake {page-number}: minor technical mistake : important language/formatting problem (page-number): language change or minor formatting problem ?page-number?: reader question or request for clarification Confirmed errors: (26) Figure 2-5.; The IP Phone addresses are wrong. Should end 103 and 104, instead of 03 and 04. (114) 6.2.2.5, 2nd paragraph; Most of the codecs in use on VoIP networks were defined by ITU-T recommendations in of the G variety... should probably be Most of the codecs in use on VoIP networks were defined by ITU-T recommendations in the G variety... {115} 2nd paragraph; Book says that uLaw and ALaw are two variants of the G.711 codec, one using a logarithmic digitizing scale to garde amplitude levels, while the other uses a linear one. This is not true, uLaw and ALaw both use a logarithmic scale. {121} 3rd paragraph; You refer to RFC 1889, which was already quite outdated when this book was printed. The current specification of the RTP/RTCP protocol can be found in RFC 3550. Furthermore in your short summary of RTP's functionality, you have completely neglected two of its most important features: timestamping and sequence numbering. (152) Figurec7-9; Between "A" and "B" there is now "Invite 5105@oreilly.com". It should be 5150 (not 5105). {154} Figure 7-11.; "madelyn@orelly.com" should be "madelyn@oreilly.com" {162} Figure 7-13; "INVITE to jake@oreilly.com" should be "INVITE to 3002@oreilly.com" {193} 1st paragraph; On page 193, you wrote: "Research has established that round-trip latency less than 150 ms is not immediately noticeable, but latency higher than 150 ms is discouraged, and latency higher than 300 ms is considered unacceptable." Actually, the majority of other literature sources (including ITU-T recommendation G.114, which is also referenced on page 193 in your book) uses these numbers not as boundaries for the round-trip latency, but for the one-way latency.