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Sasha,
Section 1.4 of <draft-ietf-mpls-diff-ext-08.txt> contains the
following text:
" For a given FEC, there may be more than one LSP
carrying the same
OA, for example for purposes of load balancing of the
OA; However in
order to respect ordering constraints, all packets of a
given
microflow, possibly spanning multiple BAs of a given
Ordered
Aggregate, MUST be transported over the same LSP.
Conversely, each
LSP MUST be capable of supporting all the (active) BAs
of a given
OA.
"
which applies both to E-LSPs and L-LSPs.
So, I believe (i) the ordering constraint and (ii) the requirement
for L-LSPs to support all active BAs of an OA are already accurately
addressed.
The only question is whether the readability of the document would
be improved by some wordsmithing in section 1.2. If you feel that would
help, we can slightly modify the beginning of section 1.2 into:
" A single LSP can be used to support one or more
OAs. Such LSPs can support up to eight BAs of a given FEC,
regardless of how many OAs these BAs
span."
Do you feel this would improve readability?
If yes, can you confirm the above suggestion is fine?
Cheers
Francois
At 18:15 05/04/2001 +0200, Sasha Vainshtein wrote:
>
>Hi,
> The reordering issue has
been addressed in
><draft-ietf-diffserv-new-terms-04.txt>,
> "New Terminology for
Diffserv" with an explicit reference to work
> on MPLS Support of
Differentiated Services.
> Section 5 of this I-D
introduces the notion of an Ordering
>Aggregate (OA) as
> <quote> A set of
Behavior Aggregates that share an ordering
>constraint.
> The set of PHBs that are
applied to this set of Behavior Aggregates
>
> constitutes a PHB
scheduling class. <end of quote>
>
> I suggest that
<draft-ietf-mpls-diff-ext-08.txt> should be updated
>to
> allow only grouping of
multiple OAs (and not BAs as it does) into
> a single E-LSP. The current
I-D version explicitly states
> that L-LSP is established
for a given (OA, FEC) class but is
> ambiguous when it comes to
E-LSPs.
>
> Nabil, in his message in
this thread, has noticed that RFC 2597
> defines
AF<x><y> (y=1,2,3) as an OA for any fixed value of x (1-4).
> The suggested modification
would prohibit configurations like one
>described
> in the original message.
>______________________________________________
>With best regards,
>Sasha Vainshtein
>mailto:
sasha@axerra.com
>phone: +972-3-7659993 (office)
>fax: +972-3-6487779 (office)
>
>
>>>-----Original Message-----
>>>From: N S S Kishore Kankipati [mailto:kishore_iitb@yahoo.com]
>>>Sent: Thursday, April 05, 2001 3:39 PM
>>>To: flefauch@cisco.com; liwwu@cisco.com
>>>Cc: mpls@UU.NET
>>>Subject: Diff-Serv over MPLS
>>>
>>>
>>>hi all
>>> Could any of you please explain about the following
>>>sentence in the draft-ietf-mpls-diff-ext-0.8.txt.
>>>
>>>section 1.2-- Exp-Inferred-PSC LSPS (E-LSP)
>>>
>>>"A single LSP can be used to support up to eight BAs
>>>of
>>>a given FEC, regardless of how many OAs these BAs
>>>span."
>>>
>>>A small doubt
>>> Suppose PHBs related to a PSC have been assigned to
>>>different E-LSPs (say AF11 to one LSP and AF12 to
>>>another LSP)and first few (say 1-10)Packets belonging
>>>to a microflow have been assigned to AF11 and later
>>>packets (say 10-15) to AF12.
>>>Is it not possible for the packets in AF12 LSP to get
>>>transferred before the packets in AF11 LSP? If that is
>>>the case the ordering constraint is violated i.e
>>>packets are reordered. (I think this may happen in
>>>the following case- if the LSPs are on different
>>>interfaces of a router and there may be some packets
>>>which are required to be served in the AF11 while the
>>>packets in AF12 may get immediately served as there
>>>are
>>>no packets before these which require service).
>>>
>>>thanks
>>>kk
>>>
>>>__________________________________________________
>>>Do You Yahoo!?
>>>Get email at your own domain with Yahoo! Mail.
>>>
>
PLEASE NOTE NEW CONTACT DETAILS - See below _________________________________________________________________ Francois Le Faucheur Development Engineer, IOS Layer 3 Services Cisco Systems Office Phone: +33 4 97 23 26 19 Mobile : +33 6 89 108 159 Fax: +33 4 97 23 26 26 Email: flefauch@cisco.com _________________________________________________________________ Cisco Systems Europe Domaine Green Side 400, Avenue de Roumanille Bātiment T3 06 410 BIOT SOPHIA ANTIPOLIS FRANCE _________________________________________________________________
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