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

[Roy Bynum <rabynum@xxxxxxxxxxxxxx>]

Joshua,

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.
>
> Thanks,
>
> Joshua