Subject: selection of next hop in cr-ldp

From: "gopinathg" <[email-masked]>
Date: Thu, 14 Jun 2001 21:16:47 +0530

Hi

   I have a question regarding selection of next hop  in cr-ldp.......

   From section 4.8.1 of draft-ietf-mpls-cr-ldp-05.txt   step 1.  is as
follows

      Step 1
         .-------------------------------------------------------------. If
the L bit is set
      and the local node is not part of the abstract node described by
      the first ER-Hop, the node selects a next hop that is along the
      path to the abstract node described by the first ER-Hop. -------

   Do we need to proceed to step 2&3 if the above condition is satisfied or
do we need to
   exit from algoritham ?

   If it proceeds thru step 2 & 3 the LSP may not pass through all the
ER-Hop's.

   steps 2 ,3 are as follows

      2. If there is no second ER-Hop, this indicates the end of the
      explicit route. The explicit route TLV should be removed from the
      Label Request Message.  This node may or may not be the end of
      the LSP.  Processing continues with section 4.8.2, where a new
      explicit route TLV may be added to the Label Request Message.

      3. If the node is also a part of the abstract node described by
      the second ER-Hop, then the node deletes the first ER-Hop and
      continues processing with step 2, above.  Note that this makes
      the second ER-Hop into the first ER-Hop of the next iteration.

Thanks In Advance

Gopinath.G.S
HCL Technologies
CHENNAI  600 006

http://www.hcltechnologies.com
Ph work: +91-44-8291735/36/37 ext-629
Ph Res  : +91-44-8292491

---

From: Eric Gray <[email-masked]>
Date: Thu, 14 Jun 2001 13:10:22 -0400

Gopinath,

    These steps do not precisely constitute a 'procedure'.  The intent of
the steps is defined by the lead-in statement -

"To determine the next hop for the path, a node performs the following
steps" ...

If - as stated - the steps are intended to produce a next hop for the
path, then the process is complete when a next hop is determined.  I
do not believe - since this is not strictly a procedure - that there is a
needs for an explicit 'exit' statement.

    Hopefully this helps...

--
Eric Gray