img
.
Page1    Page120                                                                        Page122  Page177
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.
121