Linksys SPA2002-ER User Guide - Page 41

The FXS interface is the same as that in the SPA-2000. Please refer to the SPA-2000 section for more details on configuration of this interface. 4.2.2. FXO Interface This is the interface to the FXO/LINE port. It controls the exchange of signals between the SPA and the PSTN line attached to the FXO/LINE port. It draws power from the PSTN line and controls the on/off hook state. This interface can be configured under the [Regional] and [PSTN Line] tabs, with the following functions: - Polarity reversal detection: SPA can detect polarity reversal of the tip-to-ring voltage as a PSTN disconnect signal (section 4.7) - CPC signal detection: SPA can detect CPC or momentary removal of tip-to-ring voltage as a PSTN disconnect signal (section 4.7) - Disconnect Tone detection: SPA can detect the occurrence of disconnect tone on the PSTN line; the characteristics of this tone is configurable (section 4.7) - PSTN voice activity detection: SPA can monitor voice activity on the PSTN line and consider the call has ended if no activity for a long period (section 4.7) - Ring detection: The characteristics of the ringing signal to detect can be finely adjusted with the following parameters: o - lower limit of the frequency of valid ring signal o - upper limit of the frequency of valid ring signal o - minimum duration of valid ring signal o - minimum Vrms of a valid ring signal o - delay in de-asserting a ring signal after it is removed from the PSTN line o - delay in assert ing a ring signal after it is detected on the PSTN line - DTMF detection: Detects DTMF digits on the PSTN line - FAX Tones detection: Detects FAX CED and CNG tones on the PSTN line - Parallel handset detection: SPA detects if the PSTN line is being used by another extension sharing the line, if the tip-to-ring voltage drops below the - : Increase or decrease the signal level sent to the PSTN line. The valid range is from -15 dB to 12 dB in 1 dB increment. Note: Increasing this gain may increase the level of echo heard on the VoIP call leg, while decreasing it may reduce the level of the same echo - : Increase or decrease the signal level received from the PSTN line. The valid range is from -15 dB to 12 dB in 1 dB increment. Note: Increasing this gain may increase the level of the echo heard on the VoIP call leg, while decreasing it may reduce the level of the same echo - Caller-ID detection and decoding: SPA can detect and decode Bellcore Type I Caller-ID (FSK) signal on the PSTN line after the first ring - : SPA supports 16 impedance settings - Sends these signals to the PSTN Line: Tones, DTMF, On/Off Hook - Miscellaneous parameters for international compliance control: o - Adjust the Tip/Ring voltage on the PSTN line o - Adjust the minimum loop current at which the SPA can operate o - If enabled, it limits the loop current to a maximum of 60mA per the TBR21 standard o - Set the impedance of the ringer o - Adjust the time for the loop current to drop to 0 after the SPA takes the FXO port on-hook To get the most out of your SPA-3000, it is highly recommended to connect a PSTN service to the LINE port with Type I Caller-ID subscription. This will allow the following additional functionalities: © 2003 - 2004 Sipura Technology, Inc Proprietary (See Copyright Notice on Page 2) 41