Are You Using the Fast Lane of the Internet?

Are you using the fastest backbone service available from your institution? Here is the way to find out. This article gives you examples of how to test your network connectivity, find where your connection is travelling, and measure end-to-end Transmission Control Protocol (TCP) performance. It also suggests how to tune your TCP application for fast wide-area network to get maximum throughput.

Introduction

The vBNS (very high performance Backbone Network Service) is a nationwide network that supports high-performance research applications. Started in 1995, vBNS (see image above) is a five-year cooperative agreement between MCI Worldcom and the National Science Foundation (NSF). Technical support for connections to the vBNS and for projects using the vBNS is provided by the NSF-funded National Laboratory for Applied Network Research (NLANR).

As of today, vBNS has made 88 connections and is still growing. The current vBNS is implemented as an IP-over-ATM network running on a Synchronous Optical Network (SONET) OC-12 that transmits 622 Megabits per second (Mb/s). The newly installed (January 1999) OC-48 link between San Francisco and Los Angeles marked vBNS as the first network to carry production traffic at 2.488 Gigabits per second (Gb/s).

The most significant newcomer to the high-speed backbone arena is Abilene, a project of the University Corporation for Advanced Internet Development (UCAID) in partnership with Qwest Communications, Cisco Systems, Nortel Networks, and Indiana University. Abilene is being implemented as the most advanced and far-reaching research and education network in the United States. Launched in February 1999, Abilene is now providing service to 37 universities and expects to have more than 70 connections by the end of this year. The current backbone is operated at OC-48 (2.488 Gb/s) speed, with plans to bring in OC-192 links (9.952 Gb/s). Currently, Abilene "peers" (connects to) the vBNS at one point near Chicago. (And if this is all "alphabet soup" to you, take a look at an online glossary for acronym and abbreviation expansion.)

How can you tell if you are really using these high-speed network services? How much bandwidth can you get between two machines? Finding out is as easy as 1, 2, 3.

1. use ping to test network connectivity
2. use traceroute to test the routing
3. use ttcp or nttcp to measure the end-to-end TCP performance

Need Help with Your Network Application? No Problem.

The NLANR distributed application support team is funded by NSF and provides free application support for the 150 institutions that are NSF Advanced Network Infrastructure awardee sites. Support is provided to institutions connected to either the vBNS or Abilene, plus those with awards but not yet connected.

If you need help with your distributed application, please feel free to contact us. We also host a technical workshop every several months to teach you coding strategies for distributed applications. For more information, please visit our website at dast.nlanr.net or give us a call at 1-888-643-7666.