送交者: BerkeleyWolf 于 2005-2-21, 02:35:20:

回答: ADSL带宽最多不过1Mbps,凭这点带宽私建网吧简直是开玩笑. 由 fagus 于 2005-2-20, 18:52:37:

ADSL standards
Introduction






http://www.cisco.com/en/US/tech/tk175/tk15/tech_protocol_family_home.html

Asymmetric Digital Subscriber Line. One of four DSL technologies. ADSL is designed to deliver more bandwidth downstream (from the central office to the customer site) than upstream. Downstream rates range from 1.5 to 9 Mbps, whereas upstream bandwidth ranges from 16 to 640 kbps. ADSL transmissions work at distances up to 18,000 feet (5,488 meters) over a single copper twisted pair.

http://en.wikipedia.org/wiki/ADSL

Standard name Standard type Downstream rate Upstream rate
ANSI T1.413 Issue 2 ADSL 8 Mbit/s 1.0 Mbit/s
ITU G.992.1 ADSL (G.DMT) 8 Mbit/s 1.0 Mbit/s
ITU G.992.2 ADSL Lite (G.Lite) 1.5 Mbit/s 0.5 Mbit/s
ITU G.992.3/4 ADSL2 12 Mbit/s 1.0 Mbit/s
ITU G.992.3/4 Annex J ADSL2 12 Mbit/s 3.5 Mbit/s
ITU G.992.5 ADSL2+ 24 Mbit/s 1.0 Mbit/s
ITU G.992.5 Annex L ADSL2+ 24 Mbit/s 3.5 Mbit/s

• 这里谈中国电信提供ADSL,你扯USA干嘛? - fagus (0 bytes) 2005-2-21, 06:51:13
  • so china doesn't follow international standard? since most - steven (183 bytes) 2005-2-21, 16:55:28

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