Subject: RE: RE: LDP/CR-LDP

From: Jeremy Lawrence <[email-masked]>
Date: Fri, 24 Mar 2000 18:09:16 +1100

Don & John,

One response inline.

At 17:31 03/23/2000 -0500, Don Fedyk wrote:

>Please see the comments below, 
>
> > -----Original Message----- 
> > From: [email-masked] [<mailto:[email-masked]>mailto:[email-masked]] 
> > Sent: Thursday, March 23, 2000 9:43 AM 
> > To: [email-masked]; [email-masked] 
> > Subject: RE: RE: LDP/CR-LDP 
> > 
> > 
> > VPNs and QoS are created by edge routers and can be done in many ways, 
> > some discusssed openly in IETF and others more 
> > vendor-specific.   Cisco 
> > uses BGP-based RFC-2457 as a means to distribute VPN membership 
> > information among the edge routers.  everst intent was to establish 
> > virtual routers at the time IP interfaces are provisioned.   
> > Cisco uses 
> > RSVP to signal L2 paths to create specifc LSPs for the VPNs. 
>   
>I believe that Cisco uses TDP now and LDP in the future to create 
>specific LSPs. Has this changed ? 

No. To qualify "future", Cisco has demonstrated working LDP code
(with Nortel and others), though LDP is not yet in the
fully-tested-and-shipping code. One nuance of RFC2547 (and
draft-rosen-rfc2547bis-00.txt) is that LDP or TDP is used to set
up LSPs for the aggregate traffic between edge LSRs, where 
each edge LSR is part of the service provider's network and
supports numerous VPNs. LDP or TDP not used to "create specific LSPs
for the VPNs". Hierachical labelling is used so that a top-level
label is not used for each VPN; a second level of labelling is
used to carry VPN information. The labels for the VPN information
are distributed by piggy-backing them on the BGP distribution of
the VPN routing information.

Regards,

Jeremy Lawrence