Speed

(Posted late again! Whoops!)

Every time I write my 1,000 words it is a challenge but sometimes it is more of a challenge. As I’ve said before, sometimes I know roughly what I want to include, while other times I pick a topic and go for it. This post is one of the latter.

Speed. Anyone who has been on the Internet since the early days knows about speed. When I hear people complaining about the speed of their connection I quietly laugh as I consider the days of dial-up, and of 2400 baud modems. A megabit download could take half an hour to an hour if the connection held up that long.

A Telia SurfinBird 56k modem, made by Telia. T...

A Telia SurfinBird 56k modem, made by Telia. They often came with a Internet package from the company in the late 1990s. (Photo credit: Wikipedia)

As an aside, the “skreee, Kaboinga, boinga, boinga, skeeee…” of a dial up modem connecting induces nostalgia in me, though I’d not go back to those days! Today’s Internet is sometimes called the Information Superhighway. The old dial up Internet was much like a dirt road. With potholes.

When one takes a journey, say from one end of the country to the other, one sets out on local roads, which may or may not be congested, then one travels over the Motorways, or the Interstates, or the Autobahns. Then one travels on the local roads at the far end. Any of these may be congested, but the local roads are most likely to be slower to traverse.

English: An automobile on the sweeping curves ...

English: An automobile on the sweeping curves of the Autobahn with view of the countryside. (Photo credit: Wikipedia)

The same is true of the Internet. Your local ISP is equivalent to the local roads at your end of the trip, and the target website or whatever you are connecting to is in their ISP’s local network.

If we delve a little further, it is evident that the copper or fibre that makes up the Internet is not really a factor in the speed of the Internet. Signals in the fibre travel at light speed. Typically this is less than light speed in empty space, but it is close to it. Signals in copper travel slower than this, but still at a significant percentage of the speed of light. (I’d put a link in here, but the subject is complex and I found no clear explanation. YMMV).

English: Fibre Optic cables sign at Exe Water ...

English: Fibre Optic cables sign at Exe Water Bridge Over the last few years fibre optic cables for TV and phones have been laid along many rural roads. Usually the indication of their presence is the presence of manhole covers at intervals along the road. Here it is evident that the cable had to go beside the road at the bridge – and probably under the river – so the sign is a warning to other utilities who may dig up the roadside. (Photo credit: Wikipedia)

The real reasons that fibre is preferred over copper is the huge bandwidth and the much smaller attenuation in fibre cables. Bandwidth is often described in terms of how many lanes a highway has. Obviously the more lanes the more traffic a highway can handle. Attenuation is interesting. It’s as if your car starts out in New York in pristine condition, but deteriorates en route to Los Angeles, until it arrives at its destination looking like a bucket of bolts, if it makes it that far.

Whether or not the packets are transmitted by fibre or copper, the signal must somehow be loaded onto the cable, and this takes significant time. The packet of data is placed into a register on the network connector by the computer and a special chip translates that to a stream of bits on the wire, or pulses of light in the fibre.

These pulses then whiz off onto the network. However they don’t travel all the way in one hop. Your computer connects to a modem device that sends the signal to your ISP, where the signals hit a router. This device looks and a whole packet of data, then send it off again towards its destination. It doesn’t get to its destination in one hop, and there may be a dozen or more hops before it gets there.

At the beginning and the end of each and every hop there is a device that grabs the packet of data off the wire, decides where to send it and puts it on another wire. These devices are called ‘routers’, a term which many people will have heard. As you can imagine, each hop adds a delay (or latency) to the packet of data. These delays are quite small but they add up.

English: Avaya ERS 8600.

English: Avaya ERS 8600. (Photo credit: Wikipedia)

So the Information Superhighway doesn’t look that flash after all. Sometimes I wonder how data actually gets through at all. It’s as if there was a multi-lane highway across the country (the world even), but it is studded with interchanges which take significant time to traverse, increasing the time taken for the trip – light would take nanoseconds to get from here to Sydney if we had line of sight, but over the Internet it takes milliseconds.

Satellites are even worse. To reach a geostationary communications satellite and return takes of the order of half a second, an age in computing terms. Of course most communication satellites are lower than that so the delay is not as much as half a second, but it is still significant.

The advent of streaming services has exacerbated the problem. The basic issue is twofold. To use the motorway analogy, there are many more cars on the road and as a result the interchanges are becoming crowded resulting in congestion. In general the motorways themselves are fast and free-flowing, but the interchanges have not caught up.

An ingenious partial solution is to strategically place machines around the world which effectively distribute the stuff that people want to receive, so that the same content is available locally. It’s like taking all the copies of the pictures in a gallery in Los Angeles and storing the copies in New York, Miami, Washington and so on. Rather than having to go all the way to Los Angeles, a New York viewer sees the picture locally.

In the diagram shown, we see an "Akamaize...

In the diagram shown, we see an “Akamaized” website; this simply means that certain content within the website (usually media objects such as audio, graphics, animation, video) will not point to servers owned by the original website, in this case ACME, but to servers owned by Akamai. It is important to note that even though the domain name is the same, namely http://www.acme.com and image.acme.com, the ip address (server) that image.acme.com points to is actually owned by Akamai and not ACME. (Photo credit: Wikipedia)

So the sources of delay to your streaming the latest version of TV shows are many. The first possibility is your own setup. Maybe your network and modem are not up to the task. Secondly there is the telecom network. Tricky stuff happens between you and your ISP which if the province of the telcos. I don’t know the ins and outs of it, but in some cases switching a couple of connection in the roadside cabinet or in the exchange helps.

Then there is your ISP. ISP will be keeping a close eye on the traffic through their part of the network, but the rapid rise of the streaming services has caught them a little bit unawares, and some are scrambling to keep up. Then there is the Internet backbone. It is unlikely that there are issues here. Finally there is the target ISP’s network and the target site’s network and the site itself. Any of these could cause issues, but they are way beyond the control of the end user and his/her ISP.

Speeds on the Internet are phenomenal when compared to the early days. Things are much more complex these days. It is amazing what can be achieved, and those of us who have experienced the early days are less likely to whinge about speed issues as we remember that it was like!

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