Category:  Internet

The discussions following my “All-I-can-eat mentality” post have helped me get a much better understanding of the broadband access business issues. I’ve already shared some of them in a follow-up post. A few weeks later (just before leaving for my summer vacation) I’ve tried to provide as balanced perspective as I could manage in the “Broadband traffic management: Finding rational solutions to ease congestion” article I wrote for SearchTelecom.

Read the SearchTelecom article

In one of our discussions, Stretch provided an excellent graph illustrating that the ISP competition seems to reduce prices almost linearly and asked me in a later comment to justify the inverse relation between subscription charges and consumer choice.

You might consider this debate to be purely between Stretch and myself, but it’s an interesting example of what you might need to do in daily your job. If you want to be a great networking engineer, you have to be prepared to question everything, including common wisdoms, “well-known truths”, “common practices” and facts that look too good to be true. Ready? Let’s go …

The “All-I-can-eat-mentality” article has triggered (as expected) numerous responses. Some of them provided useful data, links to more information or informative perspectives – many thanks to those readers. A few others were unfortunately following the “I-am-right” line without considering facts. Most of the readers from the Service Provider community decided to stay anonymous (when you read all the comments, it becomes obvious they made a wise decision) or respond off-line.

Whatever your position in this issue, I would like to ask you to keep your comments focused on the topic. Although you were all infinitely more polite than the usual forum/blog crowd and provided some really good arguments, writing angry replies does not help. What’s happening with Internet is (like it or not) our common problem … or you could take the blue pill and continue bashing the other side.

I particularly liked the summary of our discussion posted on Slashdot (where someone included the link to my blog):

Whoa, whoa, whoa, that article seems to be promoting a balanced viewpoint that denies a) that telcos are totally evil and b) that we should all be allowed to have as much bandwidth as we want and not have to pay for it. We'll have none of that nonsense on /.

We all know that the global BGP table is exploding (see the Active BGP entries graph) and that it will eventually reach a point where the router manufacturers will not be able to cope with it via constant memory/ASIC upgrades (Note: a layer-3 switch is just a fancy marketing name for a router). The engineering community is struggling with new protocol ideas (for example, LISP) that would reduce the burden on the core Internet routers, but did you know that we could reduce the overall BGP/FIB memory consumption by over 35% (rolling back the clock by two and a half years) if only the Internet Service Providers would get their act together.

Take a look at the weekly CIDR report (archived by WebCite on June 22^nd), more specifically into its Aggregation summary section. The BGP table size could be reduced by over 35% if the ISPs would stop announcing superfluous more specific prefixes (as the report heading says, the algorithm checks for an exact match in AS path, so people using deaggregation for traffic engineering purposes are not even included in this table). You can also take a look at the worst offenders and form your own opinions. These organizations increase the cost of doing business for everyone on the Internet.

Why is this behavior tolerated? It’s very simple: advertising a prefix with BGP (and affecting everyone else on the globe) costs you nothing. There is no direct business benefit gained by reducing the number of your BGP entries (and who cares about other people’s costs anyway) and you don’t need an Internet driver’s license (there’s also no BGP police, although it would be badly needed).

Fortunately, there are some people who got their act together. The leader in the week of June 15^th was JamboNet (AS report archived by Webcite on June 22^nd) that went from 42 prefixes to 7 prefixes.

What can you do to help? Advertise the prefixes assigned to you by Internet Registry, not more specific ones. Check your BGP table and clean it. Don’t use more specific prefixes solely for primary/backup uplink selection.

Every few months, my good friend Jeremy finds a reason to write another post against bandwidth throttling and usage-based billing. Unfortunately, all the blog posts of this world will not change the basic fact (sometimes known as the first law of thermodynamics): there is no free lunch. Applied to this particular issue: