Much has been said about traffic engineering with explicit routing vs. tuning of IGP metrics. After a thorough analysis of alternatives, including a full mesh of static and/or dynamic RSVP-based tunnels, T-Com (AS3320) has decided to use the IGP metric-based approach of traffic engineering for its global IP/MPLS-based network.

We show how we get the traffic matrix with a home-grown algorithm [1] based on MPLS counters or "LDP statistics," thus avoiding the need for a full mesh of tunnels just to do the measurements.

We also show how we represent the real network in a suitable way for simulation and optimization tools.

Last but not least, we discuss some general design issues concerning the IGP metric design. General requirements for IGP metrics in the context of traffic engineering might easily contradict requirements for iBGP route reflection (see "BGP Persistent Route Oscillation Condition," RFC3345.)

[1] S. Schnitter, M. Horneffer: Traffic Matrices for MPLS Networks with LDP Traffic Statistics. Proc. Networks2004, VDE-Verlag 2004.

About the Presenter
Martin Horneffer is a member of the Internet Backbone Architecture team that is responsible for engineering and architecture of the backbone of T-Com's global IP/MPLS-based network. Before joining Deutsche Telekom in 2001 he was with the Regional Computing Center of the University of Cologne, engineering and operating Germany's largest university's IP network and network services. Martin holds a Masters degree in Electrical Engineering from the University of Technology Aachen and a Ph.D. in Computer Science from the University of Cologne.