Geek Stuff

Multicast

Say you need to distribute a large file to many people and you want to do it on the Internet. Today you would put the file on a server and tell people to download it. Then the targets would go and try to download the file from your host server. If you have 500 kbps connection to the internet and you have 1000 (1k) people trying to download it at the same time, each person will be downloading at 500 bits per second.

Let’s say the file is a large one, like a feature length movie. The movie would play at 10 Mbps for 8000 (8k) seconds (2 hours 13 minutes). That’s a total of 80 Gbits, or 10 GBytes. A 10 GB file is fairly large. And that’s with 8 bit bytes. What if they decide to go to 16 bit bytes to provide better color definition? That file just doubled in bit size. But I digress; we are going to stay with 8 bit bytes.

At 500 Kbps, it would take 45 hours to send the file. Just to one person. It is left to the reader to determine how long it would take at the 500 bits per second we postulated above.

There are many ways to reduce the download time, including reducing the size of the file with additional compression (at 10 mbps, the video is already compressed 150 times from an original 1.5 Gbps video signal. I’m talking HD quality here.) , reducing the frame size so it only fills a quarter of the screen, and other methods that reduce the over quality of the resulting image. Or you can increase the size of you network access trunks and hope that you ISP can handle your sized traffic on the other side of the router. A 50 Mbps OC1 should let 100 users have 500 kbps access to your server and it should only cost you an arm, a leg and a head every month.

Now, how about broadcasting a single 500 kbps stream into the internet? And let anyone who wants, to tap in to the stream as it passes by. If you send out your file in a continuous loop for a week or so, everyone who wants will have a chance to tap in. And the network isn’t being tied up with lots of repetitive streams.

This streaming technique is known as Multicasting. The source makes a multicast address available and lets others know what it is. The multicaster starts streaming and interested parties notify their local routers that they want to connect to the multicast address. The routers start querying other routers for the multicast address and when they find a router that has the multicast passing through, that router starts streaming the multicast to the requesting router. The requesting router doesn’t have to go back to the source router/server, just the nearest one with a stream. Now the requesting router can become the source for other requesting routers. And the stream can go around the world on a single thread.

If you think that some of your prospective users can’t access the net at 500 kbps, then cast a stream at 50 kbps and another at 5 kbps. As long as you have 555 kbps that should work. (If not, reduce the first stream to 445 kbps. We’re flexible. We’re not expecting people to use these streams to view real-time video.)

This multicast technique would work very well for online radio stations since it doesn’t matter when you tune in, you just listen to the music from the point you find it and not worry about what came before. For large file transfers, it is a little different. The user needs to capture all the information to have a useful file. If the file that is being distributed is broken into a lot of discreet packages and each package is labeled X of 100000, X+1 of 100000, etc. and the file is multicast in a loop for a week or so, the receiver just needs to collect all the packages to reconstruct the original file. So if a connection is lost, or goes down, for a while, the receiver can tune back in to the multicast and collect the missing packets.

There needs to be software that can parse the packages and another to recover the file. I think that already exists. All we need is a viable Multicasting network. It’s part of the IP protocol, it just hasn’t been activated on most routers because there are some overhead and network utilization problems. Probably the biggest problem will be the financial one. If a router is acting as a Multicast bridge, passing the stream on to other requesting routers, does the router owner get any money out of it? Tying up resources without recompense, what sort of world is this, anyway?

This may be argued for a long time, since the Internet is a network of networks and it is the responsibility of a network to pass traffic through even if that network is not a target with the understanding that other network will do the same with its traffic. But Multicasting hasn’t really taken off, for a variety of reasons.IPv6 should help get it rolling. It will be interesting to see what sort of business opportunities develop with the new IP.

Geek Stuff, General, Politics

Telecoms Winning the WiFi War (washingtonpost.com)

Telecoms Winning the WiFi War (washingtonpost.com) This article in the WP discusses how the Pennsylvania legislature is passing a bill that will prevent local municipalities from setting up Wi-fi networks and providing free or low-cost internet access to its citizens, in competition with the local Telco. If the muni wants to do this it needs to talk to the LEC (usually Verizon in PA). If the LEC can’t commit to delivering a local Wi-fi network in 14 months then the muni can deploy their own. Philadelphia has already got permission from Verizon to go ahead with its Wi-fi network that has been i the plannig stages for awhile. (evidently this is what sparked the legislation in the first place. )

So why wouldn’t every muni in PA immediately go to the LEC and make the request RIGHT NOW? Verizon hasn’t bothered to widely deploy broadband services for several years. Why should they start now. And then, in 14 months, the Muni’s that don’t have a Wi-fi network can build their own if they have the interest then, or the money. Just because they start the clock ticking now doesn’t mean they have to build anything in 14 months, but at least they have the option.

General, Reviews

The Avengers

Over several years I have been collecting the DVD set of the original 1960’s Avengers. I have been looking at some of the last Patrick Macnee/Linda Thorson episodes this weekend. And then realized that I am missing one last set of DVDs, the one with the final episode. Arrrggghhh! I was hoping I wouldn’t have to go out this weekend.

The Avengers is one of my favorite TV shows of all time, especially the Diana Rigg episodes. Didn’t really care for Tara King as a sidekick for Steed. She was too young for the part. But, it was the writing, more than anything, that left me with such fond memories of the original airings and made me glad to find the DVDs. The stories were often over the top and silly, but they were so well done, the silliness was part of the flavor.

On a message board over at IMDB Someone asked a question about who would be good actors to play Peel and Steed in a new series. I don’t think we can bring back Peel and Steed. They were defined 40 years ago by the original actors and that’s done. The best you can do today is develop a new show with the same quality writing and let a new generation of actors define a new set of characters.

I don’t have enough familiarity with the modern crop of British actors to suggest a “Steed” character. I wonder how the guy who played Hamish has matured? I can’t see someone like a Hugh Grant carrying it off. It’s got to be someone who acts in their thirties and has the “gravitas” to carry off the physical activities. Maybe one of the MI 5 actors?

The “Peel” character is the tricky one. I think Thorson’s main problem, aside from her age, is that she didn’t have the same physicality that Diana Rigg did. And it seems to be harder to find actresses with a physical presence today, many seem to want to waste away into good-looking wraiths. Jessica Alba, Geena Davis, Uma Thurman, Brigid Fonda; all have done good action roles. I liked Halle Berry as Jinx but I don’t know if she has that right degree of “physicality” I am looking for. Again, I think the actress as to be acting as a thirty-something; the character has to have some life experience under her belt before tackling Intercrime, or the Cybernauts, or the Hellfire Club…

An interesting project, to be sure. I thought the Avengers Movie, from several years ago, was rather poorly done, mainly in the writing. As I remember it, Fiennes as Steed and Thurman as Peel did well fitting into the characters as defined. And letting Connery ham it up as the villain was in character for the series. It was certainly silly enough. The Writing, and Directing, just sucked.

General

White Hats

I think I have heard of this being done on a small scale, but why doesn’t the good hacker community, the ‘white hat hackers’, write anti spam-bots that will go out and clean up all the hi-jacked systems that are sending out spam because some little virus told them too. Distribute the good viruses the same way bad ones are done and you should reach most of the infected boxes in a hurry. And the good bots could close all the trap doors and do stuff to prevent a PC from being re-infected, inoculate them.

And just to make sure the user knows, after all the clean-up is done, a little message pops up to tell the prat what was done to help them out.

I’ll bet the white hats could stay ahead of the black hats, easily. Wish I was a hacker…

General, Politics

Government Priorities

I believe that one of the government’s greatest responsibilities is to protect its citizens, the People that the Government is for, from the inhuman entities that rule most of society’s financial life. I speak, of course, of corporations.

On the whole, I support the principle of corporations. A corporation provides a means for a group of people to create and develop goods and services that can’t be done by individuals, even individuals trying to work together as a group. But they need to be watched closely, monitored and reined in at all times. Unfortunately, it appears that the group mentality needed to make a corp work overrides a lot of the individual cares and concerns that the government should be concerned with. There is plenty of historical precedent with the manufacturing industries, the rail industries, the mining industries, the shipping industries, the banking industries the insurance industries, the petroleum industries, the agriculture industries, the textile industries… Are there any industries that haven’t abused the group power of corporation?

At the simplest level, I think it starts when the person who hires an individual isn’t the one who pays the individual. The hirer is an agent for someone else and may have the power to hire/fire/promote/ individuals, even say how much they will be paid, but the wages come from somewhere else. This is the beginning of a corporation. At this point the worker starts to lose the ability to negotiate face to face with the persons ultimately in charge since the they are distant or a distributed group.

At this point, the government should be providing some oversight, ensuring basic employee rights and minimum wages.

Once a corporation is selling stock for public ownership the government should be monitoring these public companies to make sure they are not lying to the public and that they are following generally accepted accounting principles. As someone who worked for WorldCom, I really, really would have liked to see a little more oversight of public companies.

There are plenty of historical incidents that demonstrate that corporations do not act in the best long-term, or short-term, interests of the citizenry. And that Corporations will use their money to buy social and political influence to weaken whatever monitoring is in place.

Once the People have been badly burned and have put strait-jackets on corporations to prevent them from repeating the sins of the past, everyone starts to game the system and tries to come up with a strait-jacket work-around. What’s even more mind boggling is that these are individual citizens that are working to screw the rest of the country. Part of the game is to avoid taking responsibility for the negative impacts that the gaming will produce.

to be continued

General

More Inquiry

Inquiring Minds have several other big hitters.

There was a Canadian TV show that sort of stays on on the web even though the show is defunct.

And CSICOP has a page for sceptical investigators. (CSICOP is a good organization for learning how to debunk the alternate realities that some people create.)

I really want to get one of those Darwin Fishes, but I don’t ornament my car, so it doesn’t do much good.

General

Strange links

I used the phrase “Enquiring Minds want to know” in a previous post and thought that “Enquiring Minds” would be a good blog title so I googled and found this site:alt.usage.english.FAQ.

I found they have lots of interesting tidbits of english usage and origins of phrases and words. I thought their explanation of using verbs with group nouns (e.g. company, herd, flock, pod) was very edifying.

I didn’t see an EM blog pop out of the google search but I didn’t look past the first page and it had 44,000 hits.

Oh yes, The EM phrase I started with was a result of the National Enquirer ad campaign in the ’80s.

The Thoughts and Luminations of Jack Heneghan