Re: [nznog] FYI: Telecom changes the ADSL playing field again...
Barry Murphy
21/10/2004 10:23:04 a.m. >>> Telstra Clear already do this with their tempest service, if you purchase a 256k connection, check your router status and you'll see you are connected at 288k. They at least give 32k leaway.
Not really - that 288k is 288k of ATM bandwidth... It translates (as best I can figure) to 31.32Kb/sec or 250.56kbits of real world transfer... So you're actually getting more than 256kbits of raw traffic, it's the TCP overheads that bring the number below 256. Cheers - Neil G (Reference : http://www.broadbandreports.com/information/kb/maximum+DSL+speeds/ATM) quoted below maximum DSL speeds Maximum DSL speed is a function of distance, the gauge (thinness) of the phone wire used in your locale, and the DSL technology employed. The fastest DSL now commonly available is ADSL, and it offers maximum download speeds of up to 7.1mbps and around 1.1m upload. Most residential ADSL is limited to 90-680k for download, depending on the Telco. SDSL currently has a max of 1.5mbps, but that is both up and down (symmetric). Other common rates are (in k bits per second) 640k/90k, 1600k/90k, 680k/680k for ADSL. Rule of thumb for converting speeds to something easier to understand: take the k bps, and divide by 10. This is the maximum transfer K per second you are ever likely to see in a browser download window. More accurately, divide by 8 and take off 13%, which is overhead from tcp/ip and, more importantly, ATM overhead. (DSL lines use ATM as an underlying data-transport protocol). Modems range from 2-5k a second, DSL lines from 10-500k a second, office computer interconnections are usually either (best case) 800k a second (10mbit) or 8000k a second (100mbit switched). NOTICE: This message contains privileged and confidential information intended only for the use of the addressee named above. If you are not the intended recipient of this message you are hereby notified that you must not disseminate, copy or take any action in reliance on it. If you have received this message in error please notify Allied Telesyn Research Ltd immediately. Any views expressed in this message are those of the individual sender, except where the sender has the authority to issue and specifically states them to be the views of Allied Telesyn Research.
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neil gardner