What transfer speeds can I expect (i.e. what download rates) on my Internode ADSL service?
When talking to a well-connected Australian server, you should typically be able to approach the ‘full possible speed’ of your chosen ADSL line rate. Note however that normal ADSL overheads mean that this rate is not the speed that the line is quoted at technically. Rather in the same manner as the size of hard drives is quoted, the theoretical line speed and the practical maximum line speed are different. These overheads are twofold – they are caused by overheads inherent in the underlying framing protocol of xDSL (called ATM cell encapsulation), and also in the overheads inherent in the size of the headers in the Internet’s TCP/IP protocols (entirely normal and unavoidable parts of how good transmission protocols work). The nett outcome of this is that, for instance, a ‘1500 kilobit per second’ ADSL service will only ever achieve around 1250 kilobits per second (give or take a little) under ideal conditions. This is normal and fine. Similar proportional differences between ‘theoretic
