Version 3.0.1 63 July 2010
MP-20x Telephone Adapter 5. Configuring VoIP Parameters
5.8 Configuring Telephone Interfaces
Use the 'Telephone Interface' screen to enable and disable FXS (telephone interface)
parameters.
¾ To configure polarity reversal:
1. In the 'Voice Over IP' screen, click the Telephone Interface tab; the 'Telephone
Interface' screen opens.
Figure 5-14: Voice Over IP - Telephone Interface Screen
2. Select the check box 'Enabled' to enable the Polarity Reversal feature. When this
feature is enabled, the FXS polarity is reversed to indicate the start of a VoIP session,
and is reversed back when the VoIP session ends.