Position Statement

Debbie Perouli, PhD Student

Sonia Fahmy, Associate Professor

Computer Science DepartmentPurdue University

WODNAFO 10

Central Problem

Simplify an experimental scenario

before we study it

using simulation, emulation, or testbeds.

Main Focus:

Preserve the important

routing characteristics

for this scenario.

Characteristics of the Problem

Why simplify?

Large scale (ASes, prefixes, messages) meaning

high memory requirements, long execution times

What is important to preserve?

Depends on the goal of the experimenter, and

which properties may change with the scale

Why do it before running the experiment?

This is just one approach...

Platform # of ASes Memory Reference

Based on SSFNET 650 300 MB [LN]

BGP++ 2500 1 GB [DR]

SSFNET (INET) 16000 N/A [HK]

BSIM 18943 N/A [KFR] PGBGP

C-BGP 20000 300 MB [QU] C-BGP

Where are we now?

Glenn Carl, Towards Large-Scale Testing of Policy-Based Routing via Path Algebraic and Scaled-Down Topological Modeling, Ph.D. Dissertation, The Pennsylvania State University, May 2008.

References I[DR] X. Dimitropoulos and G. Riley, Large-Scale

Simulation Models of BGP, MASCOTS, 2004.

Shared memory among RIBs, Nix-vectors. Also parallel.

[HK] F. Hao and Pramod Koppol, An Internet Scale Simulation Setup for BGP, ACM SIGCOMM CCR, 2003.

Single global RIB, no TCP/IP modeling.

[LN] L. Liljenstam and D. Nicol, On-Demand Computation of Policy Based Routes for Large-Scale Network Simulation, Winter Simulation Conference, 2004.

PAO routing algorithm, no routing dynamics.

Graph Topology Tools

Generators

Orbis [MH]: given a set of metrics of a small graph, produce a larger graph preserving those values

could we use it in the opposite way?

Reducers

HBR [HF]: sampling method which produces a topology preserving the hierarchical structure of the Internet

Topological Scale Down [CK]

Remove nodes through Gaussian elimination, rewire edges, modify policy configuration.

Preserves

path length, composition & ordering

import policies, i.e. local preference

Also, developed a BGP solver (no TCP/IP) based on Path Algebras.

References II[CK] G. Carl and G. Kesidis, Large-Scale Testing of the Internet's Border Gateway Protocol (BGP) via Topological Scale-Down, ACM TOMACS, 2008.

[KFR] J. Karlin, S. Forrest, and J. Rexford, Pretty Good BGP: Improving BGP by Cautiously Adopting Routes, ICNP, 2006.

[HF] Y. He, M. Faloutsos, S. Krishnamurthy and M. Chrobak, Policy-Aware Topologies for Efficient Inter-Domain Routing Evaluations, IEEE INFOCOM Mini-Conference, 2008.

[MH] Priya Mahadevan, Calvin Hubble, Dmitri Krioukov, Bradley Huffaker, and Amin Vahdat, Orbis: Rescaling Degree Correlations to Generate Annotated Internet Topologies, ACM SIGCOMM, 2007.

[QU] B. Quoitin and S. Uhlig, Modelling the Routing of an Autonomous System with C-BGP, IEEE Network, 2005.

Thank you!

depe@purdue.edu

Are graph metrics important?

RV Source 1998 (March 27) 2003 (March 8) 2009 (March 31)

# of Nodes 3518 15029 31220

# of Edges 8039 31019 64376

Average Degree 4.57021 4.12789 4.12402

Assortativity -0.254805 -0.192823 -0.199657

Clustering 0.156501 0.272716 0.220455

Metrics in Routing Papers

(1) # of candidate or best paths

(2) path length

(3) # of BGP updates

(4) protocol convergence time

(5) end-to-end delay (intra-domain)

(6) # of prefixes and origin

(7) # of infected nodes or links

(8) node degree distribution