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Appendix 22. WAN in Lab: A Wide Area Network in a

laboratory, and High Throughput Transport Protocols

http://wil.cs.caltech.edu/

Steven Low (slow@caltech.edu) and Lachlan Andrew (lachlan@caltech.edu)

January 2008

WAN in Lab:

Caltech's WAN-in-Lab [1] is a 2400+km long haul fiber optic test bed, located in a single

laboratory, to allow detailed control and measurement. Initially built to aid FAST TCP

research, WAN-in-Lab is now used for a variety of networking research and is being

equipped to provide a publicly available TCP benchmarking facility. It seeks to fill the

gap between emulation and live network experiments

The heart of WAN-in-Lab are four Cisco 7609 routers, several spans of optical fiber and a

MEMS optical switch to connect dynamically reconfigure the network. Additional line cards

were added in April 2007, giving the four routers the following connectivity:

1.

Router A: Three 2.5Gbps OC48 ports

2.

Router B: Three 2.5Gbps OC48 ports

3.

Router C: Two 2.5Gbps OC48 ports and three 10 Gbps ports

4.

Router D: Two 2.5Gbps OC48 ports and three 10 Gbps ports

In addition to these, there are four pairs of Cisco 15454 ONSs, and 24 spools of 100km of single-

mode fiber. These can be configured to provide a total of over 120ms delay at 2.5Gbps,

equivalent to trans-Atlantic distances, and simultaneously 8ms delay at 10Gbps.

One of the long-term goals of the WAN-in-Lab team was to connect to the Ultralight network

testbed used by high energy physicists. WAN-in-Lab now has a 10 Gbps layer-3 connection,

through Ultralight's presence in Caltech's Center for Advanced Computing Resources. This will

allow much greater flexibility, and offer the possibility of running experiments in the presence of

live cross-traffic.

WAN-in-Lab can be used in either of two ways. Those who simply want to test their own TCP

stacks on WAN-in-Lab can register for a benchmarking account. This will let them upload their

kernel, book time, and evaluate TCP protocols by running standard tests. For more detailed

experiments users can obtain login accounts, configure the network themselves and design their

own tests. Access is primarily via Ssh to wil-ns.cs.caltech.edu, although some access is available

via remote desktops. The first point of contact for WAN-in-Lab is by email to wil@caltech.edu.

TCP Benchmarking:

Benchmarking of TCP protocols is the quantitative comparison of the performance of a new TCP

proposal with the performance of other varieties on a standardized set of tests.

TCP benchmarking has been chosen as a primary application of WAN-in-Lab, and its

configuration is being tailored to that task.

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