Traffic Engineering like a pro

Surely a non-topic?  Isn’t traffic engineering a simple case of throwing internet traffic towards the lowest cost destination?  This may be how many Internet Networks approach traffic engineering in their earliest days, but how far can this strategy scale?

Most of the time, the strategy breaks when a failure event on the network poses the question “could we have done better?”  A failure event could be an outage that leads to congestion, loss of service, or unnecessarily high latency to a particular destination.  Most of these have cost (sending traffic “around the houses”) or revenue (customers getting fed up and leaving) implications, but for most networks in the world some careful planning significantly reduces the impact of failure at their Internet edge.

Managing traffic engineering projects can be boiled down to a simple checklist:

  • Establish the ‘direction’ of your traffic flow (mainly inbound, mainly outbound, or balanced)
  • Collect data that you can trust which helps you to identify which remote ASNs originate or sink your top traffic flows
  • Obtain quick wins by configuring deterministic routing with your top ‘n’ flows
  • Improve mutual long term performance for both networks by interconnecting closely to traffic origination point.
  • Measure again, review again, measure again, review again.

The techniques that enable this are explain in more detail in this presentation.

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New York, New York

Taxis at dusk

Everybody I know who loves their city claims that they live in a ‘Green City’, boasting about how every possible corner has been turned into a beautiful and relaxing park.  That said, I was genuinely surprised to see just how much expensive, precious land in downtown NYC was given up to parks and recreation space, and how simple it was to find a beautiful place to relax in dense Manhattan.

NYC delighted me because unlike many US cities, it was possible to find a distinctly local and unique heartbeat in many of the varied neighbourhoods where locals live.  My favourite neighbourhood was Greenwich Village, hosting hundreds of indie art, fashion, music and food outlets that can’t be found anywhere else in the world.  You must work hard to avoid the tourist traps, but will be rewarded when you do.

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IP Drought begins today in Asia-Pacific

That’s it – the Asia Pacific region is the first to run out of IPv4 addresses.

This happened following an assignment of around half a million addresses to support the users at the Chinanet Fujian Province Network.

The pool of available addresses to the region including some of the world’s largest populations, such as China, India, Indonesia, and some of the world’s largest economies, such as Japan and Australia, has depleted to such low levels, that the registry responsible for distribution of these addresses will now ration them, such that any ISP requesting space will be given a single block of 1,024 addresses, on a single occasion only.

This is enough space to allow the ISP only to host NAT or ipv4 to ipv6 translation technologies. It is not enough to address a large content infrastructure, hosting environment, or internet access customer-base.

The rules of the game have today changed for 50% of the world’s population, and they will change in Europe too in a few short months too. If you do not have an IPv6 plan, then this is your new significant business risk – how will users with v6 only connections reach your content? And if this is through a translation mechanism, how will you ensure quality, or that your end-to-end protocols (like voice, video, etc.) will work ?

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Bring on IPv6 party!

Tonight I will be participating at the Bring On IPv6 event, at the London Transport museum.  

It’s important for large website operators and businesses who rely on the internet to ensure their services are available on the current IPv4 internet and IPv6 internet.  At 2 billion users, the internet community has grown to reach a size that IPv4 addresses can no longer service.  To make your content available to everyone, learn about IPv6.

Bring on IPv6 party!

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LONAP Route Servers Pass Milestone

I noticed earlier that LONAP had passed a fantastic milestone just before the weekend – of the ninety nine networks which are plugged into the exchange, more than half of the networks choose to connect to each other via the route-server.

A route-server is a fantastic way for networks to start to peer (swap internet traffic) at Internet Exchanges, and results in instant success after connection.

A network with an open peering policy can connect to the internet exchange, and then get peering with more than half of all the other networks on the exchange by bringing up a single pair of BGP sessions. When a route-server peering is established, a BGP session is setup between your router and LONAP’s route database. LONAP advertise all of the prefixes of the other connected members to you, but the traffic between you and the other members flows between you and your peer directly (it does not need to traverse the route-server.)

Members do not need to open their network to their own customers at the route servers, they can send special messages to the route-servers to prevent certain networks from seeing prefixes.

Route-servers are not new, but have had a bad reputation for stability for several years. With our colleagues at several other community exchanges, including the LINX, we shared bugs, workarounds, and feature requirements with each other and the main open-source route-server vendors. Eventually, we were able to report considerable improvement in stability last December.

As a result, we at LONAP selected BIRD and OpenBGPd as our route server vendors, and built a support framework to link our configuration with the LONAP configuration system. Since then we have been advocating the route-servers to our members, and the fact that they are now providing a stable stepping-stone to more than half of our peers shows that this effort was worthwhile.

If you would like to start to peer, but need to be assured of instant success and results, then contact LONAP for information about how the route-servers at LONAP can help.

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The modern day window tax on the British internet

In 1696, King William III of England imposed a tax on glass. Essentially, houses with more than ten windows paid a levy to the government, but the tax is now remembered as unfair and very avoidable by bricking up the windows in your home.

Today there is a new tax on glass – firms who light the glass in fibre optic cable pay the government a levy based on the length of the fibre.

Again the tax is desperately unfair, and very avoidable because firms can just not roll out services on fibre. When firms avoid fibre, it hurts us all. When fibre is cheap, firms can use it to roll out super-fast broadband to their users, using the sort of technology that facilitates connections tens or hundreds of times faster than a typical UK home enjoys. It also allows service providers to increase the capacity of their network edge, and to improve the robustness of their network – for instance by building more links between their network points.

Improved robustness also means better business continuity planning options, improving the availability of their services. This tax kills faster access, and better services.

The fibre tax also worsens the conditions for international networks looking to build into the UK, for instance in order to bring their content and services to the UK market . This is not a hypothetical risk, it is a game-changer that has destroyed the business cases of several projects that we have been contributed to last year.

This morning, George Osborne was on BBC TV explaining that he saw an advancement in next-gen broadband (based on fibre optic cabling) as a priority. If this is the case, then he must commit to repealing the 21st Century Window Tax. To date, they have only considered repealing the 50p per month tax on telephone lines that has been suggested by the hugely flawed Digital Britain study.

We are just not competitive with this tax.

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Can you fill all of the Great Lakes with M&M sized /64s?

On Nanog, Owen DeLong and Larry Sheldon were discussing the relative size of the IPv6 address space:

64 bits is enough networks that if each network was an almond M&M, you would be able to fill all of the great lakes with M&Ms before you ran out of /64s.

Did somebody once say something like that about Class C addresses?

Well, this seemed like a challenge for Maths, and the answer is:

No.

There are 2,097,152 Class C networks. Assuming all M&Ms are spheroids of uniform oblate nature, radius major axis=6mm, minor axis=3mm. Volume is (4/3)Pi (Major2) Minor

They will be poured into a great lake of your choice, and we will assume random close packing (agitation mechanisms are probably best discussed off-list) and a (generous, but this Wikipedia article insists) void fraction of 32%.

Volume of m&m = 0.452cm3, occupies with spacing 0.665cm3.

Lake Erie is 484km3 – See: http://www.epa.gov/glnpo/factsheet.html

1 km3 = 1,000,000,000,000,000 cm3 484,000,000,000,000,000 * 0.665 = 321,860,000,000,000,000 m&ms needed to fill this lake.

There are 4,294,967,296 /64s in my own /32 allocation. If we only ever use 2000::/3 on the internet, I make that 2,305,843,009,213,693,952 /64s.

This is enough to fill over seven Lake Eries. The total amount of ipv6 address space is exponentially larger still – I have just looked at 2000::/3 in these maths.

THE IPv6 ADDRESS SPACE IS VERY, VERY, VERY BIG. Can we please now just go ahead and roll out some ipv6 services?

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