Adsl Speed =f(distance To Co) ?

[paulfr]

Do the effective speeds one gets from BKK ADSL, either

from True or another service, depend on distance of your

line to the local Central Office ??

In the States it sure is.

Are there areas in BKK where there is a line, but speeds cannot

be met due to distance. In some cases, service is declined.

Again, this is so in USA.

[Firefoxx]

ADSL service in Thailand and the US are VERY different. In the US, the distance from the CO determines the speed you get, and you pay a fixed price no matter what that speed is (at least that's what my friend got with his service). It can be 512k-8mbit.

In Thailand, the speed you get is based on the price you pay. So if you pay for 512k, it doesn't matter if you live nextdoor to the CO or 2KM away, you still get 512k (as long as the signal works). You just won't get 8M. I've hardly ever seen anyone declined service because of distance (other than being completely out of the service area). Of course, traditionally Thai ADSL speeds have alway been set so low that they usually can reach a few KM. True only recently changed that.

[BEJ]

Do the effective speeds one gets from BKK ADSL, either

from True or another service, depend on distance of your

line to the local Central Office ??

Yes, distance to the local exchange is important. With DSL you have a dedicated line to the place where the DSLAM(Digital subscriber line access multiplexer) is located( DSLAMS are usually placed in telecos central stations). The DSLAM is the boundary between you, your ISP's network and the internet and are connected to several subscribers. The distance from the DSLAM to your home determines how much bandwidth they can provide between you and the DSLAM. The actual bandwidth out the internet will depend on several factors: Your Isp's network, distance from your home to the DSLAM, equipment that your ISP use and quality of the lines that connect to your home. The longer you are from the DSLAM the less bandwidth you will have to the DSLAM. If your product is 256/128 (up/down) it means that your ISP have set a bandwidth limit(cap) for traffic that they allow from you through the DSLAM onto their network even if you qualify for much higher bandwidths. The actually bandwidth out to the internet is a different matter, this depends on your Isp's bandwidth and traffic over their network at a given time. In case you subscribe to True's 4Mbps ADSL and live next door to the DSLAM and wondering why you dont max out when downloading something from Microsoft, it simply means that there is too much traffic on True's network out to the internet and they are not capable of giving you 4Mbps. Put another way,if the internet had been located in a computer next to your DSLAM you would have maxed out your downloads anytime, but internet is a network of computers located worldwide. For you to get 4mbps downloads from the internet there are generally two conditions that has to be fulfilled(without cap).

1) Distance from home to DSLAM<10,000 feet (approximately)

2) ISP must have sufficient bandwidth available on their network out to the internet at time of download

Once out on the "real" internet operated by the major tier 1 providers(Global crossing, Level 3 etc.), bandwidth is no longer an issue. Current utilisation of their capacity is only 2-3 percent.