Telkom explains caching

[antowan]

At the recent Broadband Shootout held by the SAIEE Telkom explained the caching of web traffic and why they charge a premium for unshaped accounts.

In short:

- http traffic is cached on the first overseas request and all requests for that content is infact local after that.
- p2p is direct connection to unique user across the globe and has to use international bandwidth because the content cannot be cached.

We have known about the caching for a long time, but the way Telkom presented it at the Broadband Shootout made it clear that they want to charge you for international bandwidth but in fact make plans to keep all your traffic local anyway.

They don't want to differentiate between local and international traffic because it will make it impossible for them to seriously cap you on international traffic only because they cache most of it anyway!

Telkom is being a prat as always. They don't blink when they say things like these. They feel they are doing the country a favour.

Watch the video when it goes online. You will be shocked at how they make it sound like it is noble to rape the SA public.

 

[DGremlin]

The one thing that came accross from that forum was the way the reps talked, all the reps to one form or another tried to sell their product, except telkom, they stated their "facts" and made no excuses for them ... letting everyone else try fill in the void they got to leave behind.

 

[Snekko]

Caching ---WTF--

That's actually rather dumb why would they even admit that ?

So correct me if I'm wrong but lets say I visit the same international site 3 times a day, it should be cached & everything. So if it's local why is it still loading slower than the local sites mmmmm ??

And if many South Africans download from a slower site why is the download still going slow.

I think it just a scheme, maybe we should agree with them, and say exellent idea, brilliant, now make local bandwidth free (for everthing stored locally)

So we are infact paying for server space, not bandwidth mmm

Ball & Chain, Ball & Chain

 

[Moederloos]

Telkoms "story" makes zero sense. If it is true, then why are international HTTP sites unable to open when I am capped?

 

[antowan]

That is something you are going to have to wait for the caching experts on the forum to answer.

 

[asmith]

caching systems generaly check if the page you are requesting has changed (by requesting the last modified date for the page from the web server you are connecting to), and if it has changed they get a new copy. so some content will never realy be fetched from the cache because it changes all the time.
Also some sites try to prevent caching by allways sending the current time to the modified request. also any pages with parameters are generaly never cached, so if there is a ? in the url its not going to get served from the cache.

 

[LethalChicken]

so CNN.com should still hve september 11 bombings on their site ?!?!

 

[matt156]

As asmith said, caching servers (especially huge ones) are generally fairly intelligent. They check if a page has changed before just "assuming" that it has not changed. Therefore a news site like CNN will not be cached very often. HOWEVER caching does not have to happen on a page level, it happens on an object level. Therefore although the text on, say, ITWEB may change and will be retrieved live, the adverts, jpegs, popups, etc, don't change as much and will be fetched from a cache.

But caching has always been what broadband is based on - massive sharing. That's why it's relatively cheap - it only works with large amounts of people browsing, which increased the percentage change that a browsed page is in the cache. Although Telkom may have, for example, 100mb/s of international browsing requests, only, say, 50mb/s are actually fetched from overseas.

Yup, one of the biggest problems with P2P for ISPs (and this is worldwide) has always been that the traffic cannot be cached. If you want proper P2P you should buy dedicated bandwidth (at a huge premium in SA I'm afraid).

 

[BishopZA]

There is at least 1 P2P app that is cache-friendly: eMule. You can configure it to route data downloads through a caching proxy server. The idea is that all the users in a country/area/ISP use the same proxy server and thereby get the chunks of cached data from the proxy. Should work like a dream here in SA, but of course the protocol data still needs to go over international connections (however it is a trickle compared to the cacheable data).