Nortel Networks RTU-292 Operations Manual, Recommended Phone Line Settings, Type of System

RTU-292 Operations Manual

Table 2-2	Recommended Phone Line Settings
Type of System		Send & Receive Levels
Dial-Up lines in a U.S. Domestic phone system		-9 dBm
Dial-Up lines in most non-U.S. telephone systems		-9 dBm
PBX Systems		-12 dBm
Field Wire not connected to a telephone network		-6 dBm

When using the RTU-292 in a domestic U.S. dial-up telephone network, the MAXIMUM level allowed into a telephone line at the subscriber end is -9 dBm. Putting more level into the line than this will NOT increase performance, but will result in distortion, crosstalk into other circuits and the telephone company may disconnect the call. When operating into a PBX system, the level should be set at -12 dBm. Higher levels than these may be only used into field wire or dedicated or private lines, which are KNOWN to accommodate higher levels.

The send and receive levels are set by SW2-1, 2,3 as follows:

Factory default settings are indicated by an asterisk *

Table 2-3	Telephone Send/Receive Levels
SW2-1	SW2-2	SW2-3	Level
Off	Off	Off	O dBm
On	Off	Off	-3 dBm
Off	On	Off	-6 dBm
On	On	Off	-9 dBm *
Off	Off	On	-12 dBm
On	Off	On	-15 dBm
Off	On	On	-18 dBm
On	On	On	-21 dBm

JPS Communications, Inc. 2-6