tzlee.com/blog

Tag: BGP

  • A Word On Amazon Web Services

    Today’s lecture was given by folks from Microsoft and Amazon. The Microsoft part was on the Imagine Cup 2010, a global student competition. I’m out of bounds already, so I won’t talk about that. 😛

    The most part was on Amazon Web Services (AWS). It’s pretty interesting how they had created a variety of products from technology and be able to monetize it, but I think the concept of utility computing is still at its infancy, or maybe early teens. The huge complexity here is the billing. Amazon bills for memory, CPU, disk, I/O bandwidth, etc. That’s a pretty exhaustive way to suck your money! I’d much prefer a billing scheme more like my mobile phone where I pay a flat rate a month and get billed some extras. While the aggressive billing ensures low contention on AWS, it is not economically viable for small companies to jump on it yet.

    There was a fair bit of discussion about pricing. Surely the sales folk looked uneasy and was all ready to stand up and defend himself, but let me add a few words in their defense – real bandwidth is expensive. A 1 Gbps “dedicated” link costs upstream providers like SingTel IX and StarHub IX an average of S$10,000 per month. We may find AWS slower here because of the latency we get transiting our Tier 2 providers (SingNet Broadband, StarHub MaxOnline) taking the cheapest (and thus longer) routing paths. We all think BGP is a distance algorithm, but in reality it can be easily manipulated using a technique called AS-prepend and policy-based routing.

    If you want to read about bandwidth, I wrote an old blog entry here.

    Most of our servers here load up slow in the US for this matter, so if you have a business that wants to reach millions around the world, you will probably not want to host it in Singapore, and when you start thinking of deploying overseas, manpower (or your time and air ticket) alone would make you think about switching to AWS instead.

    P.S. My angmor is getting from bad to worse. I didn’t realize I was writting terrible Engerish until I read some very old documents I wrote back during school days. This is what the working society does to you! Argh!@#!@

  • What You Need to Know About Your Internet Connection

    Due to the recent APCN2 undersea cable outage, I read quite a bit of complaints from subscribers and thought I should write a little educational entry on how the Internet works.

    What are you really paying for?

    When you buy a connection to your ISP, you are merely buying the link from your home/office to your ISP. Theoretically speaking, ADSL users should have the first advantage over Cable Modem users as the Cable Modem sits on a shared topology.

    The ugly truth about the bandwidth test.

    However, this isn’t much of a concern as your nearby POP (Point of Presence) would usually have enough bandwidth to take care of this so subscribers always get near maximum bandwidth up to this point; StarHub users should be familiar with the annoying Bandwidth Test that always seem to report excellent bandwidth. If it doesn’t, your physical line might be faulty.

    Going international.

    Beyond that, it gets a little more complicated. Data from a subscriber travel through some tens of kilometers of fiber optic cables, then to some routers and switches within your ISP. When it reaches the border – the part of the ISP that connects to the “outside world” (other ISPs, known as peers), the data goes in all directions, e.g. if the subscriber requests a site in China, it might go through Hong Kong, then to China.

    Well, that’s for data heading out. It’s a different story when the data returns from China.

    (more…)