[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: Working Group last call on Four Ethernet Drafts
Hello,
I would like to understand the motivation behind the use of the
classtype object instead of simply using the index field as a bit vector
for ethernet priorities as it is specified in the OIF UNI 2.0. This
simplifies the interpretation of the index field and reduces the number
of objects that need to be included in the message.
Regards,
Benoit Tremblay
> -----Original Message-----
> From: owner-ccamp@ops.ietf.org
> [mailto:owner-ccamp@ops.ietf.org] On Behalf Of PAPADIMITRIOU Dimitri
> Sent: January-30-09 8:42 AM
> To: Nic Neate; ccamp@ops.ietf.org
> Subject: RE: Working Group last call on Four Ethernet Drafts
>
> Nic:
>
> > -----Original Message-----
> > From: Nic Neate
> > Sent: 29 January 2009 16:05
> > To: ccamp@ops.ietf.org
> > Subject: RE: Working Group last call on Four Ethernet Drafts
> >
> > Some low-level comments on
> > draft-ietf-ccamp-ethernet-traffic-parameters-06.
> >
> >
> > (1) TLV type definition (page 5):
> >
> > Type Length Format Description
> >
> ------------------------------------------------------
> > 1 TBD Reserved Reserved value
> > 2 24 see Section 3.1 Ethernet
> Bandwidth
> > Profile [MEF10.1]
> > 3 8 [GMPLS-ESVCS] Layer 2 Control
> > Processing (L2CP)
> >
> > The reference to section 3.1 should be 4.1.
>
> indeed.
>
> > (2) Ethernet Bandwidth Profile TLV Index field (page 6):
> >
> > The index field value MUST correspond to at
> > least one
> > of the index value included in the extended ClassType
> > object ([DS-
> > TE], [MCOS]).
> >
> > The [DS-TE] reference is missing from chapter 11. Note also that
> > CLASSTYPE is defined in [DS-TE] (RFC 4124) whereas
> EXTENDED_CLASSTYPE
> > is defined in [MCOS] (draft-minei-diffserv-te-multi-class). This
> > could be made clearer by updating the text to say "The index field
> > value MUST correspond to at least one of the index values
> included in
> > the CLASSTYPE object ([DS-TE]) or EXTENDED_CLASSTYPE object
> ([MCOS])".
>
> I will clarify.
>
> > (3) Ethernet Bandwidth Profile TLV Index field (page 6):
> >
> > A given index value j can be associated to at most N
> > Class-Type
> > values CTi (i =< N) of the extended Class-Type
> object. This
> > applies in case a set of one or more CTi maps a single
> > (shared) BW
> > profile. An example of value setting consists then in
> > assigning
> > an arbitrary value (comprised within the range
> [0x08,0xF8],
> > defined by the 5 MSB of the Index field) associated to a
> > set of
> > CTi. This allows mapping to one of 248 pre-defined CTi
> > sets.
> >
> > It is unclear exactly what the range of values for defining
> a set of
> > CTi is.
> > - The range [0x08,0xF8] contains 241 values, not 248.
> > - The 5 most significant bits of the Index field can only
> be used to
> > create 31 values (excluding 0), not 248.
>
> There are 16 bits in this field, the 3 lsb are used to encode
> the 8 cti defined in DS-TE: from 0x00000|000 (0x00) to
> 0x00000|111 (0x07), so 8 values [0x00,0x08[ in the group 0.
>
> The remaining values [0x08,0xFF] are allocated as follows:
>
> - The values in the range [0x08,0xF8[ are used for encoding
> CTi sets so 240 sets (30 groups as defined per msb of 8 values each)
>
> - The values in the range [0xF8,0xFF] are reserved (= 8 sets)
> i.e. the last group of 8 values is reserved.
>
> So, the last sentence should read "This allows mapping to one
> of 248 pre-defined CTi sets" but i will change the
> parenthesis from ] to [.
> thanks for catching it. i also need to change capital to
> minus letters for msb and lsb description.
>
> Thanks,
> -dimitri.
>
> > I think the text should say "...an arbirary value from the range
> > [0x08,0xFF] associated to a set of CTi. This allows
> mapping to one of
> > 248 pre-defined CTI sets."
> >
> >
> > Nic
> >
> >
> >
> > -----Original Message-----
> > From: owner-ccamp@ops.ietf.org
> > [mailto:owner-ccamp@ops.ietf.org] On Behalf Of Aria - Adrian Farrel
> > Personal
> > Sent: 24 January 2009 22:27
> > To: ccamp@ops.ietf.org
> > Cc: Brungard, Deborah A, ALABS
> > Subject: Working Group last call on Four Ethernet Drafts
> >
> > We want to last call four Ethernet drafts in a batch.
> >
> > All of the drafts are quite short, but we need to give you a little
> > extra time to read and comment, so this will be a three
> week last call
> > ending on Monday 16th February at 12 noon GMT.
> >
> > Please send your comments to the CCAMP list.
> >
> > The drafts are:
> >
> > Ethernet Traffic Parameters
> > draft-ietf-ccamp-ethernet-traffic-parameters-06.txt
> >
> > Generalized MPLS (GMPLS) Data Channel Switching Capable
> > (DCSC) and Channel Set Label Extensions
> > draft-ietf-ccamp-gmpls-dcsc-channel-ext-00.txt
> >
> > Generalized MPLS (GMPLS) Support For Metro Ethernet Forum and
> > G.8011 Ethernet Service Switching
> > draft-ietf-ccamp-gmpls-ether-svcs-02.txt
> >
> > Generalized MPLS (GMPLS) Support For Metro Ethernet Forum and
> > G.8011 User-Network Interface (UNI)
> > draft-ietf-ccamp-gmpls-mef-uni-01.txt
> >
> > I note that the last three of these are due to expire on
> February 8th
> > (i.e.
> > during the last call) so I hope that the authors can refresh the
> > drafts with a new revision with no other changes except for the IPR
> > boilerplate.
> >
> > Thanks,
> > Adrian
> >
> >
> >
> >
>
>