Recent Articles
Bemused Eyeballs
May 2012
How do you create a really robust service on the Internet? How can we maximise speed, responsiveness, and resiliency? How can we set up an application service environment in today's network that can still deliver service quality and performance, even in the most adverse of conditions? And how can we engineer applications that will operate robustly in the face of the anticipated widespread deployment of Carrier Grade NATs (CGNs) as the Internet lumbers into a rather painful phase of a depleted IPv4 free pool and continuing growth pressures. Yes, IPv6 is the answer, but between here and there are a few challenges. And one of these is the way applications behave in a dual stack environment more...
A Quick Primer on Internet Peering and Settlements
April 2012
The business world today features many complex global service activities which involve multiple interconnected service providers. Customers normally expect to execute a single paid transaction with one service provider, but many service providers may assist in the delivery of the service. These contributory service providers seek compensation for their efforts from the initial provider. However, within a system of interdependent providers a service provider may undertake both roles of primary and contributory provider, depending of the context of each individual customer transaction. In a system where there are many mutual service provision transactions it is common to see the use of a balance of services used in place of individual transaction payments between providers, and the use of inter-provider financial settlements as a means of reconciling residual imbalances in the accounting of such mutual service provision tasks. In this article I~d like to describe how this has been applied to the Internet, and look at the Internet's approach to interconnection and financial settlements. more...
It's just not Cricket: Number Misuse, WCIT and ITRs
April 2012
Another twenty five years has just zoomed by, and before you know it, it's all on again. The last time the global communications sector did this was at the WATTC in 1988, when the Internet was just a relatively obscure experiment in protocol engineering for data communications. At that time the Rather Grand telephone industry bought their respective government representatives (at the time the generally cosy relationships between governments and their monopoly telephone companies often made it extremely difficult to tell them apart!) to the Rather Grandly titled "World Administrative Telegraph and Telephone Conference (WATTC) in November 1988 in Melbourne, Australia and resolved to agree to the Rather Grandly titled "International Telecommunication Regulations." more...
Leaking Routes
March 2012
Its happened again. We've just had yet another major routing leak, this time bringing down the Internet for most of an entire country. Maybe twenty years ago no one would've noticed, let alone comment, but now of course its headline material in the media. What happened? And how could this have been prevented? Can we do better? I'd like to look at this incident in here, and also look at the implications for the current efforts to secure our inter-domain routing system, BGP. more...
Detecting Bogon Filters
February 2012
Until recently IP network operators were encouraged to set up so-called "bogon address filters" at the edge of their networks. These filters were intended to discard all incoming traffic where the source address in the IP header was from a block of addresses that was known to be unallocated. The inference was that a matching packet was either an unintentional leak from some privately addressed network domain or was generated using source address spoofing. In either case there is no point in delivering the packet, since it comes from a demonstrably fictitious source. However bogon filters have caused their fair share of connectivity problems. The question I'd like to look at here is: is it possible to remotely detect the use of these filters? more...
Addressing 2011 - One Down, Four to Go!
January 2012
It’s January again, and being the start of another year, it’s as good a time as any to look at the last 12 months and see what the Internet was up to in 2011. So lets see what has changed in the past 12 months in addressing the Internet, and look at how IP address allocation information can inform us of the changing nature of the network itself. more...
The Curious Case of the Crooked TCP Handshake
December 2011
In this article we will be delving into the behaviour of the Linux implementation of TCP, and looking at the way in which TCP establishes a connection. There are socket options in Linux that cause the TCP handshake to behave in a rather curious way. more...
Dual Stack Esotropia
December 2011
The introduction of a second IP protocol into the Internet presents many technical issues, and in previous columns we've explored many of the issues related to network engineering and infrastructure. In this column I'd like to head upward in the protocol stack to the rarefied air way up there at the level of the application, and look at how applications are managing to cope with the issue of running IPv4 and IPv6 at once. more...
The (BGP) World is Flat!
November 2011
In the previous article on the growth trends of BGP we looked at the BGP routing table, and looked at some predictive models for the growth of the size of the Internet's routing table. The conclusions made in that article were that while there is a very high level of uncertainty at present, it appears that the routing table is growing, but at a rate that does not excite any particular concern at this point in time. But is absolute size the only thing that matters in routing? Are other aspects of the Internet's inter-domain routing system growing at rates that are cause for concern? more...
BGP Growth Revisited
November 2011
BGP has been toiling away, literally holding the Internet together, for more than two decades, and nothing seems to be falling off the edge of the Internet. As far as we can tell everyone can still see everyone else, and routing appears to be working. So why should we be interested in BGP? One cause for concern is the inexorable growth of the Internet's routing system. Does this constant growth in routing imply that our routing system is growing faster than our capacity to afford ever larger and faster routers, assuming of course that we can keep on building ever larger and faster routers in the first place? Lets take a look at the metrics of growth in BGP. more...
Hacking away at the Internet's Security
October 2011
The front page story of the September 13 2011 issue of the International Herald Tribune said it all: "Iranian activists feel the chill as hacker taps into e-mails." The news story relates how a hacker has "sneaked into the computer systems of a security firm on the outskirts of Amsterdam" and then "created credentials that could allow someone to spy on Internet connections that appeared to be secure." According to this news report this incident punched a hole in an online security mechanism that is trusted by hundreds of millions of Internet users all over the network. more...
Transitional Uncertainties
September 2011
The telecommunications industry gets things wrong just as easily as it can get things right. In many ways the size of the industry is no indicator of its ability to make astute technology choices. Being large, and commanding vast resources in terms of workforce and capital does not necessarily help in making the right decisions. Some argue that it increases the probability of getting it wrong! This then brings me onto the obvious question: How will this industry manage the transition from IPv4 to IPv6? Will it be successful? Or will our children assign this exercise to the top shelf of the industry's record of failures? more...
Networking @ Home
August 2011
For me, one of the more interesting sessions at the recent IETF 81 meeting in July was the first meeting of the recently established Homenet Working Group. What's so interesting about networking the home? Well, if you regard challenges as "interesting", then just about everything is interesting when you look at networking in the home! more...
The Future of the Internet Economy: Chapter 2
July 2011
The OECD held a "high-level" meeting in June 2011 that was intended to build upon the OECD Ministerial on The Future of the Internet Economy held in Seoul, Korea in June 2008. I was invited to attend this meeting, focussing on the Internet's potential for generating innovation and economic growth as part of the delegation from the Internet Technical Advisory Committee (ITAC), and here I'd like to share my impressions of this meeting. more...
Securing BGP with BGPsec
July 2011
For many years the Internet's fundamental elements – names and addresses – were the source of basic structural vulnerabilities in the network. With the increasing momentum behind the deployment of DNSSEC there is some cause for optimism that we have the elements of securing the name space now in hand, but what about addresses and routing? In this article we will look at current efforts within the IETF to secure the use of addresses within the routing infrastructure of the Internet, and the status of current work of the Secure Inter-Domain Routing (SIDR) working group. more...
