Q&A: John Souter, chief executive, London Internet Exchange

Linx chief executive discusses life in the internet fast lane

The London Internet Exchange (Linx) sits at the heart of the UK's online world.

The vast majority of UK internet traffic passes through Linx's network of high-performance switches, housed in eight locations around the capital, mainly in the Docklands area.

The organisation's original aim was to allow UK traffic to stay in the UK, rather than be routed via the US as it once was.

But as Linx has grown, it has become a representative of the UK internet community and an influence on government policy decisions.

Computing

talked exclusively to chief executive John Souter about Linx's role and the future of the internet.

How important is Linx to the internet in the UK and Europe?

Even in the middle of the night there is 20Gb/s of information flowing through the exchange. In Europe, more than 150Gb/s of data passes through exchanges such as ours. But we are peaking close to 40Gb/s, so we are a significant proportion of European traffic.

We have about 145 members now, ISPs and content providers, and we are a global exchange - about two-thirds of members are international. Our furthest member is Korea Telecom.

The government regards Linx as part of the Critical National Infrastructure. From a resilience point of view, we have a terrific responsibility.

How do you plan for the enormous growth of the internet?

Because we are more international now and so big, we can ride with the punches to some extent. We do tend to be a moth to the technology flame. It's rumoured that the next step for network switches will be 40Gb/s equipment and I suspect we'll be standing outside the vendors' manufacturing plants waiting for it to be ready.

In recent years we've been investing heavily. We only turnover something like £3.5m, but we've been investing at least £1m and more on capital equipment each year. It's a bit of crystal ball gazing, it's a bit of an underlying process to keep looking at the hotspots and linking that to the investment policy.

What are the biggest challenges you are expecting?

Voice-over-IP is an interesting development for an internet exchange because you start to see traffic that wants to have some priority. That's a challenge. It could be an awful lot of data to ship, in packets that want to get to their destination very directly, rather than the normal internet thing where it all gets there and reassembles eventually. You don't really care that your email may take several attempts to form itself somewhere to reach its destination. With voice traffic you can't do that.

One of our sister exchanges has set up an exchange for GPRS traffic, where there is a lot more surfing now. There doesn't appear to be a lot of traffic, and we discussed having one last year, but there wasn't much demand. But with 3G developing, who knows?

We facilitate IPv6 peering but there's very little of it going on. A little while back, we had a lot of intellectual interest in multicasting. People kept saying that unicast won't work once the BBC is streaming EastEnders to every household in the UK. We enabled multicast in the exchange and nothing happened.

But the BBC is a big Linx member, and it says multicasting will have a shot in the arm this summer, because it has the rights to stream the Olympics in the UK. Two of our biggest spikes in traffic recently were the Budget - where a lot of people watched it in the office on their PC rather than on TV - and the Queen Mother's funeral which was on a weekday, so there was a much higher take up of people watching it on streaming instead of TV.

The internet is often mentioned as a likely terrorist target - how do you cope with security planning?

It's mostly diversity. We don't depend on one thing if we can avoid it. We have multiple diverse dark fibre links that we light ourselves. We have multiple locations which means the eggs are spread out over multiple baskets. We have a dual Lan - they used to be meshed so it was possible for a problem in one to spill over to the other. Now they are completely de-meshed. One is based entirely on Foundry Networks switches, the other entirely on Extreme Networks switches. If one of those vendors released a faulty software upgrade, then the other Lan carries on working.

You couldn't take Linx down now by physical attack, unless you had a whole squad of marines. You'd have to simultaneously visit several different hosting centres, beat their security, and find where we are in the buildings.

We fretted a bit about what an aircraft could do in Docklands, but to some extent there's nothing we can do about that apart from being diverse. We concentrate our fretting on things we can do something about.

Electronically, the recent scare over the TCP/IP vulnerability was very worrying. We get an inside track on these things, and we did what we could to prepare. We knew quite early on about the problem, but we found out that there was an exploit for it and have been taking preparatory steps for a while. Linx members have been busily protecting themselves for some time.

How do you see Linx's role as a representative of the internet community?

Quite early on, the government would ask our opinion about their plans, such as data retention. Out of that came the notion that we should represent our members in regulatory affairs. We now have a full-time regulatory officer.

We are also a founder of the Internet Watch Foundation. It is very hard for content providers and ISPs to know what is going on in their networks. If there is a reporting mechanism for people to identify illegal content and that information is used responsibly, it will work. All the statistics show it has - there is virtually no illegal content being hosted in the UK now.