Re: Last Call: 'Maximum Transmission Unit Signalling Extensions for the Label Distribution Protocol' to Proposed Standard

["Adrian Farrel" <adrian@olddog.co.uk>]

Hi,

2.4. MTU TLV

   The MTU TLV encodes information on the maximum transmission unit for
   an LSP, from the advertising LSR to the egress(es) over all valid
   paths.

   The encoding for the MTU TLV is:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |1|1|      MTU TLV (0x0XXX)     |            Length             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              MTU              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   MTU

   This is a 16-bit unsigned integer that represents the MTU in octets
   for an LSP or segment of an LSP.

 

Is this unnecessarily limiting? Shouldn't we support MPLS over L2 technologies that support larger than 64k MTUs?

Cheers,
Adrian