RE: comments on draft-ietf-tewg-diff-te-reqts-06.txt

["Wijnen, Bert (Bert)" <bwijnen@lucent.com>]

Inline

> -----Original Message-----
> From: Francois Le Faucheur (flefauch) [mailto:flefauch@cisco.com]
> Sent: woensdag 22 januari 2003 12:03
> To: Wijnen, Bert (Bert)
> Cc: Tewg (E-mail)
> Subject: RE: comments on draft-ietf-tewg-diff-te-reqts-06.txt
> 
> >> I now see why I did not understand. When you say "TE-LSPs are routed"
> >> then I think of "routing happens all the time for all packets".
> >> From what you suggest to add, it sounds as if you mean that at the
> >> time a TE-LSP is configured, that that is the time when bandwidth
> >> is reserved. So I guess you mean
> >>      - in which order the different TE-LSPs are configured
> >>        (or established or created) 
> >> 
> >> Did I get that? If so, then my text if probably even better.
> >> 
> 
> Alright then let's go for:
> "      - in which order the different TE-LSPs are configured
>         (or established)
> "
> 
MUCH better. Thanks

> (as I couldn't explain the difference between "created".
> 
they were choices I gave you.

> 
> >> So can you tell me (I am thick, sorry) what means:
> >>   - {TA}PSC
> >>   - <FEC/{TA}/PSC>
> >> 
> >> Maybe once you explain it to me I will get it and maybe 
> >> there is an Aha
> >> 
> 
> How about an example:
> 
> Say SP supports a class of service C1 with committed/excess concepts
> using the AF11 and AF12 PHBs.
> 
> Diff-Serv has defined a convenient term to designate all the packets of
> the DS domain whose DSCP correspond to AF11 . It is called a Traffic
> Aggregate. Let me call it, loosely, the AF11 TA.
> Clearly we also have the AF12 TA.
> 
> We look at the packets belonging to AF11 TA and AF12 TA as the ones
> forming the C1 class of service. To indicate that the reason those two
> are grouped together is because they "share a ordering constraints" (ie
> they MUST not be reordered) we call this set a {TA}PSC.
> The PSC is an existing Disff-Serv concept that precisely designates the
> set of PHBs sharing the "same ordering constraint".
> Hence the notation of "{TA}PSC" to suggest that it is a set of several
> TA whose relationship is that their PHBs belong to the same PSC.
> In brief it is really nothing else that the set of all packets in that
> domain which belong to a given "class of service".
> 
> Now clearly, depending on their destination, packets of a given class of
> service (ie packets from a given {TA}PSC ) will be transported on
> different TE tunnels. FEC is an MPLS term that sort of designate the set
> of packets that are "going on the same path from MPLS perspective".  The
> set of packets of a given class of service which are transported on a
> given tunnel are called a  <FEC/{TA}/PSC> to indicate it is basically
> the intersection of a FEC and a {TA}/PSC. 
> 
> Aha?
> 
Somewhat... but I am not a TE expert, nor an Diffserv or MPLS expert.
I can at least follow/understand the above explanation. That helps me,
thanks. If everyone else is happy with the text you have in sect 4.5,
then I won't object any longer.

I did see that Panos TRIMINTZIOS already wonders if you are inventing
new (and more complex) terminology. 

> >> > So how about breaking this up into something like :
> >> > 
> >> > "
> >> > The solution developed to address the requirements defined in this
> >> > document must address security aspects. DS-TE does not raise any
> >> > specific additional security requirements beyond the existing security
> >> > requirements of MPLS TE and Diff-Serv. The solution must 
> >> > ensure that the
> >> > existing security mechanisms of MPLS TE and Diff-Serv are not
> >> > compromised by the solution protocol/procedure extensions or otherwise
> >> > must provide security mechanisms to address this. 
> >> > "
> >> > 
> >> That sounds much better to me. 
> >>
> 
> Will update.
>  
> >> Pls check that you also addres the comments about DoS attacks as
> >> reaided by David Meyer.
> >> 
> 
> Discussed separately.
> 
Yes, but no I don't think I have seen a proposed (re)solution yet, have I?

Bert