The MPLS WG Archive

["Thomas D. Nadeau" <tnadeau@cisco.com>]

    Hi,

I would like to modify the mplsTunnelEntry to include

a few more objects as well as indexes. I wanted to

bring these changes to the list for discussion before

adding them to the TE MIB due to the fact that they

constitute a significant change, and we did not want to

surprise anyone. This change comes from my implementation

experience with the current version of the MIB, so it is

grounded in an actual implementation.

I would like to add five additional values to the mplsTunnelTable

as well as augment the current indexes with two more indexes:

mplsTunnelSrcAddrType     INTEGER,

mplsTunnelSrcAddrIPv4   InetAddresIPv4,

mplsTunnelSrcAddrIPv6   InetAddresIPv6,

     Now let me explain why. When you want to
examine the tunnel
     entry at a midpoint, it is possible for
tunnelId/tunnelInstance
     collisions to occur because the mplsTunnelId +
mplsTunnelInstance
     variables are not guaranteed to be unique within
an MPLS domain. 
     A simple example of this occurs when LSR A has
tunnelId = 1, 
     tunnelInstance = 0 and LSR B has tunnelId = 1,
tunnelInstance = 0
     which utilize the same next hop, LSR C. If one
examines the 
     tunnel table at LSR C, it is impossible to
distinguish both tunnels;
     hence, the third index. A fourth index is
required because we need 
     to support V6 addresses.

     An additional benefit of the added indexes is
that one can now
     sort tunnelEntries based on src address, which
is quite useful
     at mid-points and tunnel tails. For this same
reason, it might be
     useful to add the tunnel destination address to
the indexes of
     this table as well.
      
     --Tom