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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Coincidence...
At 02:48 PM 07-05-97 -0700, Michael Dillon wrote: > >I though that ATM cell sizes were so small in order to better support >real-time voice and video. The original ATM compromise was designed to avoid screwing up echo cancellation on the last mile loops which is very sensitive to delay and hard to adjust since it is old fashioned analog hardware and not digital. That is one of the more difficult aspects of the new xDSL technology is dealing with echo cancellation and crosstalk in those crummy old two-wire circuits. >We are already getting to the point where >1500 byte IP packets can be transmitted end to end in the same or less >amount of time as the original ATM networks were planned to be. When data >rates get this high, is there any good reason to shred packets, other than >maintaining compatibility with obsolete ATM gear? > In a word "No". However, there is no good reason to fix the length at 1500 bytes. We could set the maximum to 1500 bytes and allow these cells to be shorter. We could come up with a connectionless addressing scheme, perhaps one that the hardware manufacturers can administer. Let's be generous and say 48 bytes long. What? Oh, right, IEEE already did that with 802.3 MAC. Never mind. --Kent ~~~~~ ~~~~~ ~~~~~ ~~~~~ Note new area code ~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~ Kent W. England Six Sigma Networks 1655 Landquist Drive, Suite 100 Voice/Fax: 760.632.8400 Encinitas, CA 92024 [email protected] Experienced Internet Consulting ~~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~~ ~~~~ (If you can't reach me using 760 area code, use the old 619 instead.) - - - - - - - - - - - - - - - - -
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