Re: Question on CRC-32 (MPE)

[Moritz Vieth <moritz.vieth@fokus.fraunhofer.de>]

Simon Teh wrote:
> Dear all members,
>
>  
>
>           Currently I’m doing a study on MPE encapsulation. I got a 
> question on crc-32 field. From my understanding, I know that the crc-32 
> is compute from the whole datagram section including the crc-32 bit 
> tailer, but what I’m confusing is if we would like to compute the 
> crc-32, what is the original value for that field (crc-32). Hope some 
> expert could give me some guidance. Thanks in advance!
>
>  

Dear Simon,

Taking a look in the current ULE draft (draft-fair-ipdvb-ule-02) helps 
on this issue as well. The same paragraph that says for which part of 
the packet the CRC is to be calculated states:
"The Encapsulator initialises the CRC-32 accumulator register to the 
value 0xFFFF FFFF."

Regards,

Moritz


--
Moritz Vieth

Fraunhofer Institute for Open Communication Systems
Competence Center for Advanced Satellite Communications

Schloß Birlinghoven
D-53754 Sankt Augustin, Germany

+49-(0)2241-14-3467
moritz.vieth@fokus.fraunhofer.de