Adsl, Adsl Interface, And Adsl Settings In Screenos Devices; About Adsl; About The Adsl Interface; Adsl Settings From The Service Provider - Juniper NETWORK AND SECURITY MANAGER 2010.4 - CONFIGURING SCREENOS DEVICES GUIDE REV 01 Manual

ADSL, ADSL Interface, and ADSL Settings in ScreenOS Devices

About ADSL

About the ADSL Interface

ADSL Settings from the Service Provider

Copyright © 2010, Juniper Networks, Inc.
The following are the topics of ADSL Interface:
About ADSL on page 89
About the ADSL Interface on page 89
ADSL Settings from the Service Provider on page 89
Traditional telephone lines use analog signals to carry voice service through twisted-pair
copper wires. However, when using analog transmission, the service provider can use
only a small portion of the available bandwidth. To work around this limitation, the service
provider can use digital transmission to access a wider bandwidth on the same media,
at the same time. Because the service provider separates analog and digital transmissions,
you can use your telephone and connect the Internet with your computer at the same
time on the same line.
At the service provider's central office, the digital subscriber line access multiplexer
(DSLAM) connects many DSL lines to a high-speed network such as an Asynchronous
Transfer Mode (ATM) network. ADSL transmission is asymmetric because the rate at
which you can send data (the upstream rate) is considerably less than the rate at which
you can receive data (the downstream rate). ADSL is ideal for Internet access because
most messages sent to the Internet are small and do not require much upstream
bandwidth, while most data received from the Internet require greater downstream
bandwidth.
You can use the ADSL port on the NetScreen-5GT ADSL security device to enable Internet
access for a network—without adding additional phone lines, and without using an
additional ADSL modem. For details on connecting and cabling the NetScreen-5GT
ADSL, see the NetScreen-5GT ADSL User's Guide.
The ADSL interface on the NetScreen-5GT ADSL security device uses ATM as its Transport
Layer. The interface supports multiple permanent virtual circuits (PVCs), which are
continuously available logical connections to the network, on a single physical line (the
adsl1 interface). You can configure additional virtual circuits on the device by creating
subinterfaces (such as adsl1.1, adsl1.2).
Before you can configure the adsl1 interface, however, you must obtain the DSLAM
configuration details for the ADSL connection from the service provider, as detailed in
"ADSL Settings from the Service Provider" on page 89.
The service provider for ADSL Internet access must provide you with some details about
the ADSL connection so you can configure the security device to connect to their servers.
Not all service providers use the same implementation of ADSL; you might be given any
combination of the ADSL parameters as described in Table 26 on page 90.
Chapter 3: Network Settings
89