Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

[802.3ae] Re: Question on the Maximum number of packets per second


I can not give you the specific formula for calculating the maximum and minimum range of maximum packet transfer rate.  I do know that it is somewhat non-deterministic within that window, even from one day to the next from the same system because of clock temperature drift.  That is the reason that I do not believe that 10GbE, as it is now defined should not be part of a synchronous network infrastructure such as OTN with a +20PPM clock on the WIS and +100PPM clock on the rest of the system.

Thank you,
Roy Bynum

At 10:06 AM 5/31/01 +0200, Joshua J. Brickel wrote:

I was wondering if to find for 10GbE the maximum number of packets that will
enter on an interface per unit time can be calculated as follows...

64bytes for minimum packet + 8 Bytes Preamble/SFD + 12 Bytes IPG/EFD = 84
bytes = 672 bits

Then the maximum number of these minimum sized packets would be 10E+10/672 =
14.881 MP/s

This would seem correct, except that I have not included how much off the
transmitters clock can be.  Can this significantly alter the numbers I have
above?  If anyone has any insight as to how fast a clock could be off of the
nominal 10 gigabit rate and still be considered compliant I would appreciate
it posted.