Re: [IPFIX] Mistake in PSAMP RFCs: Selector ID length

[Brian Trammell <trammell at tik.ee.ethz.ch>]

hi Benoit, Gerhard,

I agree with the change to 64 bit, to keep it in line with every other  
protocol-level identifier (save odID, bound by the header format to 32  
bits), with the understanding that RLE will often be used to use it as  
32 bit.

However, in this case we might want as well to update 5476 with a line  
noting that all the examples use RLE.

Best regards,

Brian

On Oct 15, 2009, at 11:27 AM, Gerhard Muenz wrote:

> Benoit,
>
> Benoit Claise wrote:
> > Dear all,
> > We found a mistake in the PSAMP RFCs.
> > RFC5477
> >            8.1.2. selectorId
> >       Description:
> >          The Selector ID is the unique ID identifying a Primitive  
> > Selector.
> >          Each Primitive Selector must have a unique ID in the  
> > Observation
> >          Domain.
> >       Abstract Data Type:  unsigned16                   
> > <------------------
> >       Data Type Semantics:  identifier
> >       ElementId:  302
> >       Status:  current
> >      RFC5476, the selectorID length is 4 bytes in ALL examples (and  
> > there are many).
> >   IPFIX Options Template Record:
> >       0                   1                   2                   3
> >       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |          Set ID = 3           |          Length =  
> > 26          |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |        Template ID = 262      |         Field Count =  
> > 4       |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |     Scope Field Count =  1    |0|  selectionSequenceId =  
> > 301  |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |       Scope 1 Length = 4      |0|     ingressInterface =  
> > 10   |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |        Field Length = 4       |0|      selectorId =  
> > 302       |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |        Field Length = 4       |0|      selectorId =  
> > 302       |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- 
> > +-+
> >      |        Field Length = 4       |
> >      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > The proposed solution is to increase the Selector ID length and put  
> > an ERRATA on RFC5477.
> > 16 bits is definitely not enough and clearly not was intended.  
> > Since we can do reduced length encoding with larger identifiers, we  
> > don't see any harm in making all identifiers 64 bit
> > Feedback?
>
> 4 Bytes = 32 Bit
>
> You propose to increase it to 64 (=8 Byte), which means that both  
> RFCs need to be corrected. Or is 64 a mistake?
>
> Regards,
> Gerhard
>
> > Regards, Benoit.
> > ------------------------------------------------------------------------
> > _______________________________________________
> > IPFIX mailing list
> > IPFIX at ietf.org
> > https://www.ietf.org/mailman/listinfo/ipfix
>
> --
> Dipl.-Ing. Gerhard Münz
> Chair for Network Architectures and Services (I8)
> Technische Universität München - Department of Informatics
> Boltzmannstr. 3, 85748 Garching bei München, Germany
> Phone:  +49 89 289-18008       Fax: +49 89 289-18033
> E-mail: muenz at net.in.tum.de    WWW: http://www.net.in.tum.de/~muenz
>
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