A day in the life of the Internet: Amsterdam

AMSTERDAM, JANUARY 19 -- It's a blustery winter day and a team of network engineers, whose job it is to watch over the Amsterdam Internet Exchange (AMS-IX), glide along raised dikes on heavy black bicycles.

Locking up their transport at the doors of SARA, a national computing center serving several Dutch universities, they file into a low-brick building for the day's first cup of black coffee. On today's agenda? Keep an eye on the functioning of the Dutch Internet.

The engineers that work here have a busy day ahead since SARA hosts and manages academic and private networks, in addition to acting as the physical hosting site for AMS-IX, the only Internet exchange in the Netherlands. At least part of their day will be spent monitoring the IP traffic of 52 Internet service providers connected to the exchange.

AMS-IX is a non-profit association whose goal is to operate an exchange, or network access point, where ISPs can come together to exchange IP traffic once a peering relation has been established.

The exchange itself is not much more than two rooms full of gray cabinets that house the routers of member ISPs, but its function is an important one -- to allow Dutch ISPs to pass IP traffic generated in the Netherlands directly between themselves, instead of sending it out to the Internet. Coming together to exchange traffic at AMS-IX allows Netherlands-based ISPs to route traffic more efficiently. Otherwise, traffic sent between two Dutch ISPs (an e-mail for example) may have to pass to an exchange in the another country, usually the U.S., before coming back to the Netherlands again. Routing national traffic via international links is, of course, both cumbersome and costly.

During the day of Jan. 19, the Cisco Catalyst 5000 switch that lies at the core of the AMS-IX exchange will process peak traffic of 161G bit/sec. In December alone, the exchange transmitted over 61T bytes of data. However, while traffic tripled on AMS-IX last year, the network is nowhere near capacity, said Peter Huizer, academic computing services manager at SARA. Right now, it is running at about 10 percent capacity during peak times -- European business hours and a two-hour stretch in the evenings after dinner time.

"With our current equipment, we can cope for at least one more year," added Jan Hoogenboom, manager at PSINet Netherlands, an ISP connected to the exchange, and acting chairman of the AMS-IX board. The Cisco switches will need to be replaced soon, as the equipment is almost 3 years old, he said.

So how does it work?

The ISPs connect their routers by ethernet port to one of the two Cisco Catalyst 5000 switches, which are in turn connected together by a primary gigabit ethernet network and also a back-up fast ethernet link. One switch lives in a cabinet at SARA, the other across the road at NIKHEF, operator of a national physics research network. Once an ISP pays to connect to AMS-IX (500 euros per month for an ethernet connection and 850 euros per month for a fast ethernet hook-up), it chooses which location it prefers to house its equipment and pays the host directly. From here on out, it's up to the ISPs to bring in their routers and connect them to the switch.

Ditto for signing peering agreements; AMS-IX wants nothing to do with that, says Walter van Dijk, account manager at SURFnet bv, the academic research network operator that holds the facilities network management contract for AMS-IX and handles the administrative details of the operation. Once they are connected to the exchange, ISPs sign their own peering agreements among each other, he says.

AMS-IX as an association has only been in existence for one year, but an exchange of sorts has existed since 1992, when three ISPs were connected together with a thick yellow ethernet cable at the science park where SARA and NIKHEF are located. Today, 52 ISPs are connected to the exchange, among them @Home Benelux, Planet Online, AT&T Corp., Demon Internet and EUNet.

"We were one of the first exchanges in Europe," and quite possibly the very first, van Dijk said.

Operating AMS-IX is a pretty routine, SARA's Huizer says. The ISPs deal with the installation and maintenance of their hardware, as well as provide and manage their own individual connections to and from the exchange to the Internet. AMS-IX pretty much runs itself, Huizer says. "It's a very basic environment."

The only work involved in operating the exchange on a day-to-day basis is monitoring traffic flow, which is done using proprietary software designed by SARA. SURFnet publishes the data on the Web in real-time throughout the day and also puts up monthly figures.

Network engineers at SARA are on duty from 8 AM to 8 PM to handle calls from ISP members, then the burden of support falls on the person lucky enough to be on beeper duty. Otherwise, ISPs can call the SURFnet helpline 24 hours a day, 7 days a week for basic help.

But with AMS-IX's up-time track record of nearly 100 percent, there aren't many ISPs who call with problems, Huizer says. There has only been one "crash" and hardly anyone noticed it, Huizer boasts. That was the day after Christmas last year, when a power grid in the area sent all of SARA to a crashing halt. But since it was a holiday and happened early in the morning, Internet traffic was at an all-time low. By the time the exchange was back in action three hours later, not one ISP had complained -- probably because most of their customers were sound asleep, Huizer says.

Read the stories of individual NAPs by clicking on their city name below:

AMS-IX overview

Forum: The state of the 'Net
Discuss it with Dan Lasater, director of broadband applications and MAE architect for MCI WorldCom.