Switch User Manual
Configuring Voice Ports 12-13
SmartSwitch 1800 Voice Configuration
4W EM is the normal setting for a PBX EM tie-line interface that uses one pair of 
wires for the incoming voice signal and another pair of wires for the outgoing 
voice signal. 2W EM is for an EM tie line that uses a single pair of wires for both 
the incoming and outgoing voice signal.
AC 15A or AC 15C are 4-wire signaling systems used by PBXs to communicate 
with each other and other PBX-like communications equipment.
2W EM and 4W EM can be conÞgured in these modes, via the switches on the 
front of the SmartSwitch:
¥ 2W EM or 4W EM IS (Immediate Start), the industry standards for EM 
operation;
¥ 2W EM or 4W EM DD (Delay Dial), which will cause the SmartSwitch to 
expect an attached PBX to raise its M-lead to request a dial register. The 
SmartSwitch will respond as follows: 1) toggle the E-lead, 2) send a dial 
register to the PBX, 3) return the E-lead to its original state, and 4) wait for dial 
digits from the PBX (no dial tone is transmitted to the PBX).
¥ 2W EM or 4W EM WS (Wink Start), which will cause the SmartSwitch to expect 
an attached PBX to raise its M-lead to request a dial register. The SmartSwitch 
will respond by sending a dial register to the PBX. When the PBX indicates it 
is ready for dial digits (no dial tone is transmitted to the PBX), the SmartSwitch 
will toggle the E-lead. When the E-lead returns to its original state, the PBX 
will transmit dial digits to the SmartSwitch.
If 2W EM TE or 4W EM TE (Timed EM) is selected, you can specify a delay time 
for when the E-Lead follows the M-Lead in the TE Timer parameter (see above).
The default value for this parameter is Loop Start.
Telephony Type
This parameter, in conjunction with the Interface parameter (see above) speciÞes 
the type of interface that will be used by the voice channel. Refer to your 
SmartSwitch 1800 hardware documentation for more information about selecting 
the appropriate interface. If EM is speciÞed, you must also set Switch 2 on the 
front of the SmartSwitch to select an EM type. Refer to your hardware 
documentation for more information on EM Switch Settings.
The default value for this parameter is OPX.
Hunt Group
This parameter is not currently supported and must be set to None.
Suppression
This parameter speciÞes a level of suppression of background noise. For most 
calls, low suppression should be sufÞcient. The higher the suppression level, the 
greater the possibility that low-volume voice will be lost; therefore, suppression 
levels higher than low should be used only if it can be certain that background 
noise will be low or all of the voice transmitted will be sufÞciently louder than the 
background noise.










