The MPLS WG Archive

["Andre N. Fredette" <fredette@photonex.com>]

LDP, and therefore CR-LDP, does not provide an LSP MTU discovery 
mechanism.  The thinking (perhaps flawed) was that:

(a) Fragmentation is not usually an issue in the core of the network due to 
the large MTUs on typical interfaces, and

(b) If it is an issue in a particular domain, the MTU can be configured on 
the MPLS edge routers.  Note, I am aware that this is somewhat problematic 
because the MTU is not necessarily related to the local router, but is the 
minimum of all MTUs in the MPLS domain.

LDP and CR-LDPs are due to be released as RFCs in the next couple of weeks 
and I don't think this is serious enough to hold them back.

I'd be happy to write an extension to LDP for MTU discovery if people think 
it is necessary.

Andre

At 05:00 PM 12/12/2000 -0800, Serge Maskalik wrote:

[comments regarding MTU fragmentation deleted]


>    Existing mechanisms in RSVP-TE should be utilized for this
>   purpose. I would like to see feedback from authors of CR-LDP
>   in w/r/t to this.