Chapter 6: Configuring DSL Parameters

April 14, 2006

Step

Action

2Configure the following parameters as directed by your service provider:

Operating Mode

When the modem is connected to a service provider through a DSLAM, the operating mode is Remote (default setting).

When two modems are used in a point-to-point application (LAN extension, for example), one modem at the customer or user site is set to Remote and the second modem in the CO or wiring closet is set to Central-Office. For instruction on setting up G.shdsl parameters and other related parameters for a point-to-point modem application, go to Chapter 7: Implementing a Point-To-Point LAN Extension.

Standard Annex

Select one of the following Annexes:

Annex-Afor operating conditions typically found in the North American implementation of G.shdsl

Annex-Bfor operating conditions typically found in the European implementation of G.shdsl. This is the default mode for the modem.

Auto for automatically negotiating the Annex A or B standard by which this modem, and the device to which this modem is attached, can operate.

Startup Margin

The target signal-to-noise margin, in decibels, that the modem must achieve with a BER of 10-7or better to successfully complete synchronization. The default margin value is -10 dB. A lower margin may result in a higher data rate, but it can increase noise on the line. Possible values are -10dB through 10dB, or to completely Disable the margin.

Bit Rate Mode

Bit rate mode indicates how the modem synchronizes with the device to which it is attached in either a Fixed or Adaptive mode. The default for the modem is Adaptive mode.

Fixed mode indicates that the modem will synchronize with the other end (a DSLAM or another modem) at a fixed bit rate through negotiation. The modem will synchronize at the best rate, up to the data rate specified (see “Data Rate (kbps)” on page 6-4), that can be achieved by both ends.

Adaptive mode indicates that prior to modem negotiating a rate, the modem performs an adaptation phase during which it determines a best possible rate based on conditions of the line. After adaptive mode, the modem will then negotiate the best rate that can be achieved with the other end, based on the adaptation results.

3Click Apply.

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ADC MM702G2, MM701G2 user manual Operating Mode, Standard Annex, Startup Margin, Bit Rate Mode