CRC of Jumbo Frames.

[JOSE SIMON_1]

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

[Blazhev_1]

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]

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]

I would expect that those cards which support > de facto standard Jumbo Frames (ie > 9K) are still using the same CRC.

[JOSE SIMON_1]

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]

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.