Wednesday, November 21, 2007

IP is after all, Best Effort

There has been a rapid expansion of services over the Internet. Real-time services like stock-trading, for example, are highly quality and time sensitive. When I check stock prices in the Indian stock market in the early morning in Europe, the trading-session is well underway in India. The first inkling of a high volume day (rapid rise or fall of the market) comes from the speed of my online broker's webs-server! Because at the end of it, Internet technology is based on Statistical multiplexing of the data-packets and service requests. When the number of users is high, quality degrades - some on the server connection, some on the server processing!

So if it is best-effort, how come everyone is shifting all sorts of critical applications to the Internet? Worse, many of these services are becoming more resource hungry and QoS demanding - think of the canonical "Internet Medicine" application where your high resolution X-ray is seen by an expert halfway across the world, marked up with comments, and sent back. Or those VOIP applications which keep jacking up the voice quality because the bandwidth is available (I saw a VOIP promo which claimed CD quality audio). Or, ok, if I am driving down the Interstate and using my 3G handset to pull up a Google Map of the area. Oops too late, by the time the map loaded I missed the exit.

Are we betting to much on best effort networks???

Yes and No, it depends.

So one of the nicest things about the Internet nowadays is that you can buy the QoS you offer with your service. This means for example, paying Akamai a fortune and then some more to give you great CDNs that can limit the vagaries of best-effort delivery. Another great thing about the Internet is that it is robust - the key design criterion for its pre-cursor, the Arpanet, was that it re-route traffic automatically around problem areas (problem-areas scenarios included nuked cities in those cold-war days). Moreover, folks who design good Web services have a good idea of the underlying best-effort clause of the Internet...e.g. Blogger saves this post every few seconds as I type it in directly into their web-site.

But sometimes, things don't go as well and applications do hit the best-effort wall. In my opinion, this is mostly due to bad design rather than unsurmountable limitations of the Internet platform. For example, I recently tested a video-voip SIP telephony system where the designer sent the audio and video streams over RTP, separately and without synchronization, hoping that packet re-ordering and routing and buffering will "even out". Moreover, they didnt prioritze voice packets over video packets - bad idea, given how much delay and jitter sensitive our ears are. But on the other hand, Skype or Microsoft Live chat have implemented these services beautifully on the same best-effort Internet.

To be sure, There are some applications which cannot be left to the mercy best-effort .e.g. the 112 service (in Germany; 911 in the US).

So lets just say,

know your underlying network when you design services over it, and promise your customers things that can be delivered over the best-effort network, not a circuit switched network.

Sunday, November 18, 2007

Mobile Internet - the fight to the end, the EdGe

Starting about a decade ago, when broadband came to the consumer, it was marketed as the technology that would increase the "web-surfing" speed from the analog modem connection speeds of 56 kbps to 100s, and later 1000s of kbps. This was the marketing mantra, and ISPs touted every additional kilo-bit they could offer. But that was pretty much it. The point is, there were not too many Internet applications that made money at the time (there was no Google ad-sense) and just about the only folks making money off the Internet were ISPs and Internet equipment makers. There was no other business model other than subscription!

But now with the Mobile Internet, things are a lot different this time around in 2007. Here is a couple of reasons for why mobile operators do not want to let go of what services are running over their 3G networks

1. Mobile operators have paid up a *lot* of money for buying spectrum and installing 2-3G hardware in the early part of the decade. 3G technology that implements high-speed mobile Internet takes up a lot of this spectrum to deliver high speed Internet. Subscription models are not enough to get reasonable returns on this investment, especially since customers may not value the offered mobility more than a few dollars a month, given most of them are city-dwelling, almost always connected folks.

2. On the other hand, operators have learnt (painfully) from the seeing nimble and innovative application service creators like Google and My Space that there is a whole lot of money to be made by offering services directly to users. They missed the fixed broadband opportunity but don't want to miss the mobile broadband train.

So mobile operators are going to fight tooth-and-nail to protect what they perceive as the "next" big technology platform. I do not doubt this perception - companies like Apple (iPhone), Nokia (Ovi), and Google (gPhone?) also think that mobile Internet is huge. Not in the subscription way, but in the services way.

Lets take the example of Nokia's Ovi platform. Nokia's strength is that they make the edge device - the handset. Therefore, Nokia (or Apple or Google) will be hoping to push all the functionality to the edge. Cut out the mobile operator (again!) like this -

server =====(bit-pipe of mobile operator)==== end-device/software

Looks a lot like those money-making fixed broadband application services like Google's ad-sense. This is the heart of the battle now and ahead...the fight to the end, the edge.

Lets wrap up with the questions for a mobile operator right now
  • Do mobile operators know how to charm the end-customer like the Nokias, Apples or Googles of the World?
  • Can they break out of their "bill-them-monthy" business models?
  • Can they be as fast, as nimble, and as trendy?
  • Can they change, adapt, reform, morph, rejuvenate as fast as their new nimble competition?
  • How long before legislation or technology (e.g. WiMax) wrenches open their presently closed mobile IP networks?