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CRC of Jumbo Frames.

JOSE SIMON_1
Occasional Visitor

CRC of Jumbo Frames.

Does anybody know what algorithm is used to find the crc of jumbo and super jumbo frames which are used in gigabit ethernet?
5 REPLIES
Blazhev_1
Honored Contributor

Re: CRC of Jumbo Frames.

Hi,

according page 4 of this document

http://staff.psc.edu/mathis/MTU/AlteonExtendedFrames_W0601.pdf

the CRC-32 algorithm is used.
JOSE SIMON_1
Occasional Visitor

Re: CRC of Jumbo Frames.

i thank you. but..
actually that doc says about jumbo frames of size upto 9k. what is the case of 16k and 64 k frames. how is their crc calculated?
rick jones
Honored Contributor

Re: CRC of Jumbo Frames.

I would expect that those cards which support > de facto standard Jumbo Frames (ie > 9K) are still using the same CRC.
there is no rest for the wicked yet the virtuous have no pillows
JOSE SIMON_1
Occasional Visitor

Re: CRC of Jumbo Frames.

but the relevence of 32 bit crc loses when frame size is above 12k. i dont think 32 bit crc can be used above 12k. may be some other algorithm.
rick jones
Honored Contributor

Re: CRC of Jumbo Frames.

The main thrust behind jumbo frames was changing nothing but the MTU. So, while the CRC may start to lose effectiveness at the larger frame sizes, I doubt there is a different CRC used.
there is no rest for the wicked yet the virtuous have no pillows