jdMorgan - 6:03 am on Nov 20, 2004 (gmt 0)

ADSL versus SDSL: The important difference --and the reason to prefer SDSL over ADSL for server use-- is the definitions of these terms.

ADSL is "Asymmetric Digital Subscriber Line", whereas
SDSL is "Symmetric Digital Subscriber Line."

The symmetry referred-to is the upload/download throughput of the two methods; ADSL "downloads" faster than it "uploads", and is well-suited to use for Web clients (browsers), where the ratio of uploaded to downloaded data is about 1:10. That is, the typical Web browser downloads (receives) ten times more data than it uploads (sends). Therefore, ADSL is set up to support a lower upload speed than download speed.

On the other hand, SDSL has identical upload and download throughput. Since you are planning to use the connection for a server, the upload/download ratio cited above for clients will be reversed (for all practical purposes); A server sends ten times more data than it receives.

Therefore, the SDSL connection is better-suited for server uses. Maybe someone should standardize RADSL, with the asymmetry reversed. ;)

If the server is for 24/7 commercial purposes, I'd recommend two T1 lines, each from separate providers, dual independent servers, uninterruptable power supplies per server, dual independent electrical systems for the server equipment, dual independent cooling systems, physical security/access control to protect against data theft, a gas-type (non-liquid) fire-control system, and some sort of alarm/notification system for server outages -- These are some of the things you don't think about a hosting service providing... until they fail.

When all that is taken into account, commercial hosting starts to look a lot cheaper. But beware of paying too little; the features I listed cost money.

Jim