[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Re: ULE encryption Support.



Hi Alain,
     Good day. please see the comments inlined.

Regards,
William.

On Sun, 29 Feb 2004 Alain RITOUX wrote :
>Hi William
>
>Yes, in definfin the behaviour un ULE base specs, we'll have backward compatibility
>for future extension. My point for optional vs madatory extension, was indeed not very
>well explained : some other words should be chosen, because all I had in mind was, to
>define receiver's behaviour when he doesn't know the extension header. So two examples
>(only exmpales for the sake of extension headers, no opnion implide on the fcts).
>
>- encryption  : if not known, of course the following payload cannot be decrypted, and
>will be pure garbage. So the best behaviour sugested by sender is drop it, you won't
>understand what follows.

<William> you are right, This case is, if present MUST support optional header for any recevier :)

>- FEC : it can help to correct errors. If not known, it canot be used, but th payload
>that follows, still makes sense, so go on.

<William> I am sorry that i'm unclear about the FEC at MPE level, i was just verifying in our terminal, but here FEC is the part of our FPGA in DVB driver, even MPEG2 software driver isn't aware of FEC. Can anyone please elaborate how FEC is taken care in MPE, it will be also helpful if you can suggest any specifications which talks about FEC in MPE.

>
>So it we change the terms "Optional/Mandatory" by "Process-Next/Discard" for the
>exte header classification, would it be more clear ?
>
>I agree with you this encrypt (if needed) should be optional. Not everybodys needs
>it to, be ULE-compliant. Of course those interested shiould by ULE-Encrypion-compliant.
>
>
>Regards.
>Alain
>
>William StanisLaus wrote:
>
>>Hi Alain,
>>    Its seems when are sure to have some ext. headers as mandatory.. we can well define in as part of the standarded ULE header itself as any other IE (Information Element) in ULE header. I can see the only exception as Optional Headers support to keep the ULE header minimal. Except MUST HAVE IE's in ULE we can push all other things into optional headers, and we can leave it to the implementation whether to support those optional headers are not.
>>Regarding Encryption, i personnely feel that it should be an optional header, since it is not all Satellite network operators interest to implement encryption in L2.
>>
>>Best Regards,
>>William.
>>
>>
>