Subject: capability set #1 and #2

From: "Zhang, Jeffrey" <[email-masked]>
Date: Thu, 11 Nov 1999 15:08:35 -0500

Hi,

In addition to the strict vs. loose routing difference, #2 emphasises
the following:

         - modes of  label distribution defined in [5]
            - Downstream On Demand Ordered Control

Does it mean all the modes or just the downstream on demand ordered control?

Besides, why it's different between #1 and #2 in terms of the modes?
Don't they both require downstream on demand ordered control?

  from cr-ldp spec:
    An LSR implicitly infers ordered control from the existence of
    one or more CR-TLVs in the Label Request Message. 	

Same questions goto #5 and #3.

Thanks.

Jeffrey

-----------------

5.1 MPLS Capability set #1

   MPLS Capability set #1 includes the following components:

         - LDP basic mechanisms
            - LDP neighbor detection
            - LDP session initiation, maintenance and termination
         - CR-LDP strict explicit routed LSPs

5.2 MPLS Capability set #2

   MPLS Capability set #2 includes the following components:
         - LDP basic mechanisms
         - CR-LDP explicit routed LSPs
         - modes of  label distribution defined in [5]
            - Downstream On Demand Ordered Control

   This Capability set supports explicit routing and allows loosely
   routed segments of an explicit route.

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From: "Loa Andersson" <[email-masked]>
Date: Tue, 16 Nov 1999 17:50:21 +0100

Jefferey,

see comments below.

> Does it mean all the modes or just the downstream on demand ordered control?

Just the downstream on demand.

>     one or more CR-TLVs in the Label Request Message.

It is correct that TE path is always set up DoD, what is different
between
#1 and #2 is that it is possible to setup the lose part of an explicit
LSP.
This is done DoD as defined in [5] (i.e. the LDP specification).

I agree that there is something unclear when the same line

in some case are qualified and sometimes not. Try to correct that.

so #3 is DoD only

and #5 all four of them. Sorry for the confusion.

/Loa

-- 

Loa Andersson
Director Technology Center, EMEA
St Eriksgatan 115, PO Box 6701
113 85 Stockholm, Sweden
phone: +46 8 50 88 36 34,   mobile + 46 70 522 78 34
e-mail: [email-masked]

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From: "Loa Andersson" <[email-masked]>
Date: Thu, 18 Nov 1999 21:16:20 +0100

It is probably a bad practice to make replies to own mail, but
it opens possibilities for a lively discussion!

Jefferey,

reading the cap set spec once more makes it obvious that the 
point you brought up is valid also for one more aspect of #1 and #2:

         - LDP basic mechanisms
            - LDP neighbor detection

Note that cap set #1 excludes loop prevention mechanism as it is 
not necessary for only strictly routed LSPs, while cap set #2
includes it, something that is hardly obvious from the way we
written the text. We'll put in some text that makes this clear.

Thanks for pointing it out.

/Loa

-- 

Loa Andersson