Subject: Regarding Resource Class Attribute in CRLDP

From: "Ravi Sankar Mantha" <[email-masked]>
Date: Tue, 14 May 2002 10:04:28 +0530

Hi ,
   This is regarding resource class attribute in MPLS;
    I am facing problem in understanding the conversion from Explicit
Inclusion, Explicit Exclusion (as specified in RFC2702, section 5.6.3) to
the Resource Class Bit Mask ( RsCls field in the Resource Class Tlv in
CRLDP).
    Take the case of Explicit Inclusion, supposing the Bit Mask is 4 of bits
(for simplicity). ( in reality it is of 32 bits)
       Red - bit '0' (LSB)
       Blue - bit '1'
       Green - bit '2'
       Yellow - bit '4' (MSB).
      Suppose there is a CRLSP whose resource class affinity is INCLUDE -
Blue, this  can be encoded in the form of bit map as 0010 ( I assume that
the '0's are considered as Don't care ?), now this CRLSP can traverse
through links whose Resource Class Attributes can be 0110, 0010, 1111
 which include the color- blue) etc. If this is the way, Resource Class
Bitmap is interpreted by the CRLDP signaling protocol, I wonder how Explicit
Exclusion can be encoded as bit map, and interpreted by the Signaling
protocol ?
     It would be of great help if somebody can through some light on this.,
Thanks in advance,
Ravi