QUIC/inet/examples/mpls/ldp

The MPLS/RSVP-TE/LDP protocol models have been revised and mostly rebuilt
from scratch by Vojta Janota since the INET-20050922 release. This network
already features the new simulation models.

This is a sample to demonstrate the LDP label distribution protocol.

Following description refers to the nam trace file generated by the simulation
run.

LDP works in the ordered control downstream-on-demand mode. There is a router (2)
failure @2 secs. Failed router recovers @10 secs. The meaning of
individual colors appearing in the animation are as follows:

Black
- regular (user data) IP datagrams routed via routing table (e.g. when no label
mapping exists on the LSR)

Green
- user data routed using LIB (e.g. mapping exits on the LSR)

Red
- link state routing protocol (TED) traffic

Magenta
- LDP Hello packets

Brown
- LDP (TCP) session packets (including session establishment)

Orange
- ICMP error packets (these occur at the very beginning, since when both hosts
start sending their packets, no routes to their respective destinations exist
(until TED populates routing tables))

NOTE: The time required for failure detection is rather long and is due to the LDP
Hello interval configuration.