The MPLS WG Archive

[Curtis Villamizar <curtis@workhorse.fictitious.org>]

In message <008201c1fbcc$08e7e580$9103750a@wipro.com>, "Ravi Sankar Mantha" wri
tes:
>  Hi Don,
>     Thank you for the explanation.
>     In the Resource Class Tlv of CRLDP, the definition of RsCls, "The
> Resource Class bit mask indicating wihch of the 32 _administrative groups_
> or _colors_ of links the CR-LSP can traverse", sounds as though it can carry
> only the "Include" information in it. Thus it looks like it is out of the
> scope of CRLDP signaling to carry the "Exclude" vector. Is it not required
> to signal through CRLDP ? ( I think this is what you mentioned as the 2nd
> vector).
>     Then, what do you mean by associating semantics with one vector ?, is it
> something like supporting only one ( either Include/ Exclude) in the entire
> domain, so that the Bit Mask can be interpreted accordingly ?
> Thanks and Regards,
> Ravi



The extensions to OSPF and ISIS provide one 32 bit word to be used as
a bitmap to describe the attributes (colors) of a link.  RFC3209
provides semantics for RSVP/TE which are only needed if local-protect
is used or for inter-area LSPs (which are problematic to say the least
if attempts are made to enforce color restrictions across IGP areas).


  4.7.2. Format with resource affinities

    SESSION_ATTRIBUTE class = 207, LSP_TUNNEL_RA C-Type = 1

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Exclude-any                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Include-any                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Include-all                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Setup Prio  | Holding Prio  |     Flags     |  Name Length  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   //          Session Name      (NULL padded display string)      //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Exclude-any

         A 32-bit vector representing a set of attribute filters
         associated with a tunnel any of which renders a link
         unacceptable.

      Include-any

         A 32-bit vector representing a set of attribute filters
         associated with a tunnel any of which renders a link acceptable
         (with respect to this test).  A null set (all bits set to zero)
         automatically passes.

      Include-all

         A 32-bit vector representing a set of attribute filters
         associated with a tunnel all of which must be present for a
         link to be acceptable (with respect to this test).  A null set
         (all bits set to zero) automatically passes.

The FRR draft draft-ping-rsvp-fastreroute-00.txt provides the same
semantics with an include-any but does not support an include-all.

  3.1.1. FAST_REROUTE Object

     Class = 205  (use form 11bbbbbb for compatibility)
     C-Type = 7


              0             1              2             3
       +-------------+-------------+-------------+-------------+
       |       Length (bytes)      |  Class-Num  |   C-Type    |
       +-------------+-------------+-------------+-------------+
       | Setup Prio  | Hold Prio   | Hop-limit   | Reserved    |
       +-------------+-------------+-------------+-------------+
       |                 Bandwidth                             |
       +-------------+-------------+-------------+-------------+
       |                 Include colors                        |
       +-------------+-------------+-------------+-------------+
       |                 Exclude colors                        |
       +-------------+-------------+-------------+-------------+

 [ ... snip ... ]

     Include colors

      A 32-bit vector representing a set of attribute filters associated
      with a detour any of which renders a link acceptable (with respect
      to this test).  A null set (all bits set to zero) automatically
      passes.

     Exclude colors

      A 32-bit vector representing a set of attribute filters associated
      with a detour any of which renders a link unacceptable.

AFAIK no one really cares about CRLDP so whether they got it wrong by
providing only one word for the LSP may not be important.

Curtis