Subject: RE: draft-raggarwa-rsvpte-pw-01.txt

From: David McDysan <[email-masked]>
Date: Thu, 24 Mar 2005 13:11:28 -0500

Richard,

I have proposed adding minimal extensions to LDP that are
compatible/interoperable with RSVP-TE in use cases at the edge of large
networks or at boundaries between domains that do not require TE (e.g., the
L2VPN provisioning model) in earlier posts. I think your minimal set below
is what is needed and are modest extensions to LDP. There are a number of
other functions that I believe should not be added to PW LDP, at least the
following:
	- explicit routing
	- recording the route
	- Fast Reroute
	- resource sharing filter
	- IGP-TE interaction
	- interaction with a path computation element (pce)

Dave

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On 
> Behalf Of [email-masked]
> Sent: Thursday, March 24, 2005 11:24 AM
> To: [email-masked]; [email-masked]; 
> [email-masked]
> Subject: RE: [PWE3] draft-raggarwa-rsvpte-pw-01.txt
> 
> Regardless of which requirements have or haven't been agreed 
> by the WG, as specified in the current requirements draft, an 
> operator must be able to protect (at least a subset of) 
> MS-PWs from S-PE failure, and must also be able to check that 
> there is enough bandwidth available in the network to setup 
> new MS-PWs without disrupting existing services. If the WG 
> doesn't agree on these two requirements then we may as well 
> stop work on MS-PWs now as they will be useless without this. 
> I do not see CAC as being relevant to the current discussion 
> as this can be supported as a separate function which may be 
> used by multiple signalling protocols, i.e. it does not have 
> to be tied into a a particular routing protocol. However, a 
> MS-PW signalling protocol must support (at least):
>  
> - Signalling of bandwidth requirements
> - Signalling of class of service, e.g. DSCP/EXP (to select 
> the appropriate DS-TE tunnel and reserve bandwidth accordingly)
> - Setup of backup MS-PWs
> - Crankback (may or may not be required depending on the 
> specific network topology/requirements)
>  
> The current SS-PW signalling protocol does not support these 
> requirements. Therefore, the choice is simple, we either add 
> these into the current protocol, or use a different protocol 
> and add PW signalling support into it.
>  
> Both approaches will work, but to be honest there does seem 
> to be more to be added into LDP than to RSVP-TE. For this 
> reason, to be able to make an informed decision regarding 
> which the most appropriate protocol to use is, I would like 
> to hear further justification on why LDP should be used, 
> rather than justification on why we should use RSVP-TE.
>  
> Regards,
> Richard 
> 
> 	-----Original Message----- 
> 	From: [email-masked] on behalf of Bruce Davie 
> 	Sent: Thu 24/03/2005 08:52 
> 	To: Nurit Sprecher; [email-masked] 
> 	Cc: 
> 	Subject: RE: [PWE3] draft-raggarwa-rsvpte-pw-01.txt
> 	
> 	
> 
> 
> 
> 	--On Thursday, March 24, 2005 1:51 PM +0200 Nurit Sprecher
> 	<[email-masked]> wrote:
> 	
> 	> Hi Davie,
> 	> The requirement draft has just been accepted as a WG 
> document. That is
> 	> the requirements as stated right now (together with 
> the remarks that
> 	> were given) in the draft are acceptable.
> 	
> 	I don't believe that adoption of a requirements draft 
> as WG item in any way
> 	indicates that every requirement in the draft is agreed 
> to by the WG. It is
> 	only a starting point.
> 	
> 	Bruce
> 	
> 	
> 	_______________________________________________
> 	pwe3 mailing list
> 	[email-masked]
> 	https://www1.ietf.org/mailman/listinfo/pwe3
> 	
> 
>