ZyXEL Communications 645R User Manual
P645 ADSL Internet Access Router
What Is ADSL?
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What Is ADSL?
About ADSL
Asymmetric Digital Subscriber Line (ADSL) technology provides high-speed data access across regular
phone lines (copper wires) by making use of previously unused frequency bandwidth above the voice band.
By placing the ADSL signal above the frequency of voice signals, ADSL service is able to coexist on the
same line with your telephone service. ADSL is asymmetric in the sense that it provides a higher downstream
data rate transfer (up to 8Mbps), than in the upstream transfer (up to 832 Kbps). Asymmetric operation is
ideal for typical home and small office use where files and information are downloaded more frequently than
uploaded.
phone lines (copper wires) by making use of previously unused frequency bandwidth above the voice band.
By placing the ADSL signal above the frequency of voice signals, ADSL service is able to coexist on the
same line with your telephone service. ADSL is asymmetric in the sense that it provides a higher downstream
data rate transfer (up to 8Mbps), than in the upstream transfer (up to 832 Kbps). Asymmetric operation is
ideal for typical home and small office use where files and information are downloaded more frequently than
uploaded.
Advantages of ADSL
1. ADSL provides a private (unlike cable telephone and modem services where the line is shared),
dedicated and secure channel of communications between you and your service provider.
2. Because your line is dedicated (not shared), transmission speeds are not affected by other users. With
cable modems, transmission speeds drop significantly as more users go on-line because the line is
shared.
shared.
3. ADSL is "always on" (connected). This means that there is no time wasted dialing up the service several
times a day and waiting to be connected; ADSL is on standby, ready for use whenever you need it.