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1. Introduction
This chapter describes the TW-EA400 ADSL Router and its features and gives
a brief introduction to ADSL technology.
1.1 Router Description and Operation
TW-EA400 ADSL Router combines an “always-on” high speed Asymmetric
Digital Subscriber Line (ADSL) connection to the telephone line into a single
cost-effective solution.
TW-EA400 ADSL Router is compliant with the full-rate ANSI T1.413 Issue 2
and ITU G.dmt (G.992.1) ADSL standards, and with the splitterless ITU G.lite
(G.992.2) specification. Both Annex A (ADSL over POTS) and Annex B (ADSL
over ISDN) of G.992.1 and G.992.2 are supported. This rate-adaptive solution
is designed for Customer Premise Equipment and supports downstream data
rates of up to 8 Mbps and upstream data rates of up to 1 Mbps.
TW-EA400 ADSL Router simultaneously supports Ethernet to enable the
widest array of host connectivity. The Router performs ATM Segmentation and
Reassembly (SAR), industry standards for PPP over ATM (RFC 2364),
bridged/routed Ethernet over ATM (RFC 1483), Classical IP over ATM (RFC
1577), and PPP over Ethernet (RFC 2516), resulting in a cost-effective
solution suitable for both full rate and G.lite applications. The non-reliance on
host PC software drivers make the TW-EA400 ADSL Router ideal for
ubiquitous broadband connectivity that is not limited by host OS, processor
type/speed, or memory.
Networking support includes both bridge and router modes. Router Mode
supports advanced features such as Network Address Translation (NAT),
Dynamic Host Configuration Protocol (DHCP), and Routing Information
Protocol (RIPv2).
All setup and provisioning is performed by a simple, easy-to-use, Web
interface.
1.2 ADSL Technology
Asymmetric Digital Subscriber Line (ADSL) is an access technology that
utilizes ordinary copper telephone lines to enable broadband high-speed digital
data transmission and interactive multimedia applications for business and
residential customers. Using existing copper telephone lines forgoes the need
for upgrading or adding expensive new cable.
ADSL devices use digital coding techniques that greatly increase the potential
capacity of phone lines without interfering with regular telephone services. For
the ADSL user, this means much faster data communications and the potential
for interactive video capabilities. ADSL devices make it possible to enjoy
benefits such as high-speed Internet access, telecommuting (remote LAN
access), collaborative computing, distance learning, movies on demand and
multi-player video gaming, without experiencing any loss of quality or
disruption of voice/fax telephone capabilities.
