Re: Jumbo Frames in 10GbE?

[ted@xxxxxxxxxx (Ted Schroeder)]

Please check the document Error Characteristics of FDDI by Raj Jain.

http://www.netlab.ohio-state.edu/~jain/papers/xie1.htm

The CRC-32 algorithm breaks down at 11454 octets given the error 
characteristics he analyzes in his paper.

Ted Schroeder
Alteon WebSystems, Inc.

>I have heard some folk lore that the CRC-32 algorithm rather suddenly falls
>apart (in terms of high detection rate) above the present maximum Ethernet
>block size (1518 bytes).
>
>Indeed, there has been some pleas for "no superpackets, please!" on this
>reflector.
>
>This should be carefully checked before making any great leaps, tempting
>though it may be from an overhead perspective.
>
>Larry Miller
>Nortel Networks
>
>-----Original Message-----
>From: Joe Gwinn <gwinn@xxxxxxxxxx>
>To: Booth, Brad <bbooth@xxxxxxxxxx>
>Cc: HSSG_reflector (E-mail) <stds-802-3-hssg@xxxxxxxx>
>Date: Monday, June 21, 1999 12:34 PM
>Subject: Jumbo Frames in 10GbE?
>
>
>>
>>At 4:24 PM 99/6/17, Booth, Brad wrote:
>>>Just a small point.  One of the objectives that passed with greater than
>>>75% in Coeur d'Alene was to "preserve minimum and maximum FrameSize of
>>>current 802.3 Std."
>>
>>I don't know that the issue is going to stay decided all that long, based
>>on the recent article "Jumbo Frames gather support" (Jeff Caruso, Network
>>World, 14 June 1999, page 6), which states that IETF has published a
>>working document proposing that ethernet frames be made larger than the
>>current 1,500-byte maximum, the basic rationale being to reduce the packet
>>rate and thus load on packet-handling components of the system.  In short,
>>this is a system issue, and cannot really be decided solely at the MAC
>>level.
>>
>>If jumbo frames are to come, 10GbE would be a logical place to start.
>>
>>The issue will ultimately be decided by an IEEE Ballot Group, not a
>>Plenary.  If the market is really going to bigger packets, as this article
>>implies, it will be hard to resist.
>>
>>Joe Gwinn
>>
>>
>>
>>The above is in response to the following:
>>
>>>        >Issues 3 - Bit Error Rate
>>>        >The assumption will be that this is 10-12. If someone wishes to
>>>challenge
>>>        >this they should bring a presentation to the next meeting
>providing
>>>        detailed reasoning why this needs to change.
>>>
>>>        It strikes me that the issue of larger maximum packet sizes will
>likely
>>>        come up, just as it did for GbE.  If 10GbE goes to 9 KB packets,
>>>the design
>>>        center BER would need to go to 10^-13 to maintain the same
>theoretical
>>>        packet loss rate.   I'm not sure how much effect this would have
>in
>>>        practice, as most gigabit links achieve much better than 10^-12,
>>>if they
>>>        work at all.  Anyway, these items are ripe for debate and
>decision.
>>
>>**** end of message ****
>>
>>
>>
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