Large Scale WAN Emulation

Martin Arlitt Rob Simmonds Carey Williamson - University of Calgary

March 18, 2002 Outline

• Overview of WAN Simulation & Emulation

• Introduction to IP-TNE

• Discussion of Related Projects

• Validation of IP-TNE

• Current Projects Involving IP-TNE

• Future Work

1 Performance Evaluation Approaches

1. Experimental

+ offers the most realistic environment

- requires significant financial investment

- can be difficult to repeat results

- restricted to existing technologies

2 Performance Evaluation Approaches

2. Simulation

+ low-cost, flexible, controllable, reproducible environment

- abstractions can compromise usefulness of results

3. Analytical

+ provides quick answers

- often requires the greatest degrees of abstraction

3 Performance Evaluation Approaches

4. Emulation

* a hybrid performance evaluation methodology

* combines aspects of other three approaches

+ enables controlled experimentation with existing applications

- still suffers from drawbacks of other approaches

4 Wide-Area Network Simulation

• provides a virtual Wide-Area Network (WAN) environment

• allows all network conditions to be controlled

– packet loss – packet reordering/duplication – link bandwidths – propogation delays – asymetric links – bounded queue sizes – multipath

• allows alternative networking technologies to be evaluated

5 Wide-Area Network Emulation

• extends capabilities of WAN simulation

• enables controlled testing with unmodified applications

• both simulation and emulation are important tools

6 Challenges

• scaling to large, non-trivial sized networks

• developing realistic models of network characteristics

• keeping pace with real world events (emulator)

7 Introduction to IP-TNE

IP-TNE: Internet Protocol Traffic and Network Emulator

• developed at the University of Calgary

• a collaborative effort between researchers in:

– high performance parallel simulation (Rob)

– IP networking (Carey)

8 Introduction to IP-TNE (cont.)

Design

• built around IP-TN network simulator

• uses a high performance PDES kernel

• kernel modified to provide real-time features

• can simulate end hosts as well

9 Introduction to IP-TNE (cont.)

Operation

• reads packets promiscuously

• replies to ARP requests for registered hosts

• packets timestamped when read from network

• output time calculated by network simulator

• packets released when wall-clock time = output time

10 Introduction to IP-TNE (cont.)

Current Strengths • high performance

– this enables detailed simulation of non-trivial networks

• flexibility

Current Weaknesses

• simple models of network behaviour

• visualizing operation of large networks

• need for repeatable validation tests

11 Related Projects ns-2 • most well known network simulator/emulator

+ feature rich (e.g., multiple flavours of TCP, etc.)

- poor performance restricts size of simulated network

SSFNet + focused on simulating extremely large scale networks

- does not provide emulation capability

12 Related Projects (cont.)

Other Network Simulators/Emulators

• dummynet

• NistNet

• Utah Network Testbed

• Network Emulator 4.0

• The Ohio Network Emulator (ONE)

• Opnet

• Shunra Cloud

13 Validation of IP-TNE

Overview

• validation is not a one-time event, but a continuous process

Protocol Implementation • capture and examine network traffic

e.g., use tcpdump to capture packets between emulator and host

– examine HTTP headers and responses for correctness

– examine IP and TCP headers for correctness

– analyze TCP behaviour for correctness

14 Validation of IP-TNE (cont.)

Emulator Behaviour • compare application behaviour in real/emulated environments

e.g., Web server benchmarking

– evaluate Web server performance with benchmarking tools

– compare to benchmarking results using IP-TNE

– account for any differences; repeat tests if necessary

– can also compare to results from other emulators

15 Current Projects

Web Server Benchmarking

• demonstrate one use of IP-TNE

• helps validate our emulator (comparing to Nahum et al.)

• show that a centralized approach to WAN emulation:

– can scale to large network sizes

– is more manageable than a distributed approach

16 Current Projects (cont.)

Alberta SuperNet • what is SuperNet?

– ICT infrastructure throughout province of Alberta

– will provide high-speed Internet access to:

∗ 100% schools

∗ 95% businesses

∗ 80% residences

– 422 communities to be linked

– 5,175 miles of fiber; wireless networks in remote areas

17 Current Projects (cont.)

Alberta SuperNet

• IP-TNE will be used in development of SuperNet

• data captured from SuperNet will be used to:

– develop more realistic models of network conditions for IP-TNE

– validate IP-TNE

• project will test scalability of IP-TNE

18 19 Future Work

• improve models of network conditions

• add additional features (e.g., TCP variants, routing algs)

• make protocol validation a repeatable/automated process

• improve real-time performance of PDES kernel

• participation in SuperNet

• use ELISA (an Internet testbed) to further improve IP-TNE

20 Contact Information

Martin Arlitt: [email protected]

Rob Simmonds: [email protected]

Carey Williamson: [email protected]

IP-TNE: http://warp.cpsc.ucalgary.ca/

21 SuperNet Community Rollout Schedule - 2002

Bruderheim Lamont Chipman Mundare Enoch Devon Innisfree Lindale Beaumont Calmar Mannville Drayton Valley Thorsby Breton Warburg Millet Winfield Buck Lake

Bentley College Heights Leslieville Clive Eckville Rocky Mountain House Blackfalds Sylvan Lake Condor

Scheduled Community completion (Calendar Year) 2002 2003

2004

NOTE: Not all communities are labelled. 4 February, 2002. SuperNet Community Rollout Schedule

Zama City

Meander River

Fort Chipewyan Chateh Garden Creek

Rainbow Lake Fox Lake

La Crete Buffalo Head Prairie Paddle Prairie Tall Cree I.R. 173 Keg River

Fort MacKay

Manning Chipewyan Lake

Fort McMurray Peerless Lake Loon Lake Worsley Dixonville Trout Lake Anzac Bear Canyon Hines Creek Peace River Berwyn Silver Valley Fairview Nampa Bonanza Atikameg Wabasca-Desmarais Chard Eaglesham Sandy Lake Rycroft Donnelly Conklin Woking Valhalla Horse Lake I.R. 152BTeepee Creek Driftpile Beaverlodge Bezanson East Prairie Metis Settlement Smith Grovedale Sturgeon Lake I.R. 154 Heart Lake

Lac La Biche Flatbush Athabasca Boyle Fawcett Buffalo Lake Iron River Cold Lake Fox Creek Rochester Ardmore Glendon Blue Ridge Barrhead Clyde Thorhild Smoky Lake Ashmont Elizabeth Metis Settlement Elk Point Alexander I.R. 134Bruderheim Andrew Lafond Lamont Fort Saskatchewan Chipman Peers St. Albert Myrnam Entwistle Mundare Edson Ardrossan Vegreville Enoch Nisku Hinton Devon Tofield Innisfree Islay Lindale Beaumont Calmar Drayton Valley Mannville Thorsby Hay Lakes Bruce Breton Warburg Millet Paradise Valley Alder Flats Falun Bawlf Irma Jasper Winfield Wainwright Rosalind Killam Buck Lake Bluffton Mecca Glen Hardisty Chauvin Donalda Forestburg Bentley College Heights Amisk Leslieville Clive Eckville Alliance Czar Rocky Mountain House Blackfalds Botha Brownfield Cadogan Sylvan Lake Condor Castor Benalto Penhold Bodo Coronation Big Valley Elnora Consort Bowden Rumsey Sundre Olds Morrin Delia Hanna Carstairs Youngstown AcmeCarbonDrumheller Beiseker Cereal Airdrie Rockyford Banff Bearspaw Scheduled Community completion Strathmore Hussar Cessford Gem (Calender Year) Bassano Arrowwood Duchess Jenner Black Diamond Milo Brooks Longview Brant Tilley 2002 Vulcan Nanton Lomond Rainier Schuler Champion Ralston Stavely Carmangay 2003 Hays Redcliff Barons Dunmore Granum Picture Butte Bow Island Coalhurst Barnwell

2004 Bellevue Brocket Wrentham Blood I.R. 148 Foremost Glenwood Warner Cardston Milk River NOTE: Not all communities are labelled. 4 February, 2002. Coutts