Subject: Doubts in "draft-ietf-mpls-lsp-query-00.txt"

From: "Manikantan S" <[email-masked]>
Date: Wed, 25 Oct 2000 15:50:49 +0530

Hello Paraschiv

I read the draft "draft-ietf-mpls-lsp-query-00.txt".

I have a few doubts and can you please clarify them?

Thanks.

1) Label TLV is used in the Query message and the Query Label
   TLV as Optional parameters in the Query Reply message.
   Both the TLVs contain a set of Generalized Label TLVs.
   I am not clear as why do we require Query Label TLV and
   Label TLV i.e., two TLVs when the contents are the same?

2) ER TLV has been specified as Optional parameters in
   Query Message and in Query-reply message. I understand
   that this TLV's usage is to keep track of the hops.
   Path Vector TLV (in LDP), RRO in (RSVP-TE)helps in
   providing this information too. What is the significance
   of using ER TLV?

3) In Section 5.2 Page 9, we have
   --------------------------------------------------------------------
   Upon receiving a Query Message, an LSR decodes the label to identify
   which LSP is queried. If it cannot find the LSP which is using the
   label, it sends back a Notification message.
   --------------------------------------------------------------------
   What is the status value that should be indicated in this case?

4) In Section 6.2 Page 12, we have
   -------------------------------------------------------------------
   A Query-Reply message is initiated by an egress node which receives a
   Query message, if the egress is able to identify the queried LSP.  If
   not, the egress replies with a Notification message.
   --------------------------------------------------------------------
   What is the status value that should be indicated in this case?
   Should this be the same one as for question 3?

I noticed Following minor typos/missing info

1) Section 6.3 Page 13
   we have
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0|    Query-Reply (0x0411)     |      Message Length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

  should be
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0| Partial-Query-Reply (0x0411)|      Message Length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

2) Section 7.2 Page 16
   for "The format for the Query Label TLV " read "The format for the Merge
Flags TLV"

3) Section 7.3 Page 16
   for "The format for the Query Label TLV " read "The format for the Label
TLV"

Thanks in advance
with best regards
mani
-----------------------------------------
S.Manikantan
Future Software Limited
480-481, Anna Salai,
Nandanam, Chennai, India.
Zip (PIN CODE) : 600 035
Phone          : 91-44-4330550
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email          : [email-masked]
-----------------------------------------

---

From: "Antonela Paraschiv" <[email-masked]>
Date: Wed, 25 Oct 2000 11:23:15 -0400

Thank you for comments. Please find my answers below.
Best regards,
Antonela Paraschiv

>    Label TLV i.e., two TLVs when the contents are the same?

You  are right. The only reason I created 2 different TLVs was to make it
clearer . I could certainly remove one of them.

>    providing this information too. What is the significance

The ER TLV provides the proper format to encode a list of interface addresses.
Its only purpose is to carry the list of hops. It is not used for loop
detection as the Path Vector TLV.

> 3) In Section 5.2 Page 9, we have

3 and 4 : I will add a new Status code: "No Lsp to query" with status data =
next available.

--
Antonela Paraschiv
Carrier Packet Division, Nortel Networks
Esn   : 978-288-6136
E-mail: [email-masked]