ZyXEL Communications IES-2000, Руководство пользователя

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IES-2000/3000 User’s Guide
ALC1024 Specific Commands 7-1
Chapter 7
ALC1024 Specific Commands
The ADSL (Asymmetrical Digital Subscriber Line) subsystem allows you to configure and monitor the
ADSL ports on the ALC1024 line card.
7.1 ADSL Standards
The ALC1024 supports both the G.lite and the G.dmt standards. G.lite is intended to minimize the cost for the
consumer market.
Table 7-1 Maximum Transfer Rates of the ALC1024’s ADSL Ports
STANDARD MAXIMUM DOWNSTREAM MAXIMUM UPSTREAM
G.dmt 8160 Kbps 1024 Kbps
G.dmt Annex B 8160 Kbps 1024 Kbps
G.lite 1536 Kbps 512 Kbps
ANSI T1.413 issue 2 8160 Kbps 1024 Kbps
7.2 Profiles
A profile is a table that contains a list of pre-configured ADSL settings. Each ADSL port has one (and only one)
profile assigned to it at any given time. The profile defines the maximum and minimum upstream/downstream
rates, the target upstream/downstream signal noise margins, and the maximum and minimum
upstream/downstream acceptable noise margins of all the ADSL ports that have this profile. You can configure
multiple profiles, including profiles for troubleshooting.
Profiles allow you to configure ADSL ports efficiently. You can configure all of the ADSL ports with the same
profile by modifying the profile, thus removing the need to configure the ADSL ports one-by-one. You can also
change an individual ADSL port by assigning it a different profile.
For example, you could set up different profiles for different kinds of accounts (for example, economy, standard
and premium). Assign the appropriate profile to an ADSL port and it takes care of a large part of the port’s
configuration. You still get to individually enable or disable each port, as well as configure its encapsulation type,
multiplexing mode, VPI, VCI and operational mode. See later in this chapter for how to configure profiles.
7.3 Configured Vs. Actual Rate
You configure the maximum rate of an individual ADSL port by modifying its profile (see the
set profile
command) or assigning the port to a different profile (see the
set port
command). However, due to noise and
other factors on the line, the actual rate may not reach the maximum that you specify.
Even though you can specify arbitrary numbers using the
set profile
command, the actual rate is always a
multiple of 32 Kbps. If you enter a rate that is not a multiple of 32 Kbps, the actual rate will be the next lower