Eric:
<snip>
>
> I think GTTP adds the following functions that are
> not present in
> draft-bonica-icmp-mpls:
>
> - the ability to discover and trace through nested tunnels,
> even if the TTL
> is not percolated through the stack;
Seems to me that GTTP is "dependent" on TTL not percolating through the stack (a.k.a. the "Pipe" model).
In the "Uniform" model GTTP requests will terminate due to TTL exhaust arbitrarily in the network, and in any sort of VPN scenario (disjoint addressing) the LSR where the exhaust occured may not have a clue about the trace originator.
>
> - the ability to trace through a nested tunnel even if
> interior LSRs of the
> tunnel have no route to the management station.
By interior LSRs I presume you mean the lower level tunnels. LSRs MUST have a route to the trace originator for GTTP to provide useful information about the level under test.
Dave