The MPLS WG Archive

[Shahram Davari <Shahram_Davari@pmc-sierra.com>]

Vishal,

What you are asking is outside the scope of RFC3270 and even
out side the scope of Diffserv and MPLS WGs. RFC3270 just tells you
that you could use an L-LSP to carry a single OA. Whether that single
OA consists of voice, or video or voice+video is irrelevant.


-Shahram

> -----Original Message-----
> From: Vishal M [mailto:vishal_study@yahoo.com]
> Sent: Monday, October 21, 2002 2:46 PM
> To: Shahram Davari; mpls@UU.NET
> Cc: vishal_study@yahoo.com
> Subject: RE: Ques on RFC 3270 (MPLS Support for DiffServ)
> 
> 
> 
> Hi Shahram,
> 
> Thanks for the clarification.
> 
> I re-read the relevant sections of RFC 3270 and have
> some confusion trying to understand the concept of
> Ordering Constraint and its usage.
> 
> How does an ingress LSR decide if there is any
> ordering constraint between various packet flows it
> receives. i.e. in Section 1.4 (last para), it says
> that in order to preserve the ordering constraint, all
> possible BAs of a given OA must be sent over same LSP.
> This looks fine, but I have a doubt:
> 
> The question is:
> How does an LSR decide if incoming packets of same
> micro-flow have some ordering constraint? Where is
> this info (of ordering constraint) carried?
> 
> Assuming an video-on-demand application running on a
> host connected to an ingress LSR (doing MPLS DS TE).
> This ingress LSR would receive both voice and video
> packets (destined to different ports) on same
> destination IP Address. Since its a video-on-demand
> application, one would expect ordering constraint to
> synchronize the video with voice contents.
> Now can these video and voice packets be redirected to
> different L-LSPs?
> 
> Could you/someone please clarify this?
> 
> thanks for your time,
> 
> regards,
> Vishal.
> PS: I'm not familiar with video/voice DSPs...the above
> example just tries to provide an example of two
> different classes (i.e. BAs) arriving at an ingress
> LSR destined to same destination.
> 
> --- Shahram Davari <Shahram_Davari@pmc-sierra.com>
> wrote:
> > The label in L-LSP represents only a single OA,
> > while the label in E-LSP may represent:
> > 
> > - A single BA
> > - A single OA
> > - A number of BAs
> > - A number of OAs
> > - A number of BAs and OAs
> > 
> > " A set of BAs" is a generic term that applies to
> > all the above cases.
> > 
> > -Shahram
> > 
> > > -----Original Message-----
> > > From: Vishal M [mailto:vishal_study@yahoo.com]
> > > Sent: Friday, October 18, 2002 10:35 PM
> > > To: mpls@UU.NET
> > > Subject: Ques on RFC 3270 (MPLS Support for
> > DiffServ)
> > > 
> > > 
> > > 
> > > Hello,
> > > 
> > > Question on RFC 3270 (MPLS Support for DiffServ),
> > > Section 1.5:
> > > 
> > > The second paragraph explains about the
> > relationship
> > > between FEC and set of BAs...
> > > 
> > > Why don't we consider the concept of packet
> > ordering
> > > constaint (i.e. OA) for an E-LSP (say, E-LSP1 and
> > > E-LSP2) ?
> > > 
> > > Assuming we have two E-LSPs from the same source
> > (S)
> > > to the same destination (D). Now if an incoming
> > > multimedia packet stream from single source (of
> > voice
> > > and video traffic) is to be sent to destination
> > (D),
> > > is it possible to send voice traffic onto E-LSP1
> > and
> > > video onto E-LSP2 ? 
> > > 
> > > Why in this section, we have associated OAs with
> > > L-LSPs only (and not with E-LSPs)?
> > > 
> > > Thanks for all the inputs and pointers,
> > > 
> > > Regards,
> > > Vishal.
> > > 
> > > 
> > > 
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> 
> 
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