Cisco SPA1001 Administration Guide - Page 79

Chapter 4 Configuring the PSTN Gateway (FXO) Configuring VoIP Failover to PSTN Configuring VoIP Failover to PSTN When power is disconnected from the SPA3102, the FXS port is connected to the FXO port. In this case, the telephone attached to the FXS port is electrically connected to the PSTN service via the FXO port. When power is applied to the SPA3102, the FXS port is disconnected from the FXO port. However, if the PSTN line is in use when the power is applied to the SPA3102, the relay is not flipped until the PSTN line is released. This is done so that the SPA3102 does not interrupt any call in progress on the PSTN line. When Line 1 VoIP service is down (because of registration failure or loss of network link), SPA3102 can be configured to automatically route all outbound calls to the internal gateway using the parameters listed in Table 1-32. Table 1-32 Automatically Routing Outbound Calls to Internal Gateway Parameter Group Auto PSTN Fallback Line 1 Description If enabled, SPA3102 automatically routes outbound calls to Gateway 0 when registration fails or network link is down. Range Bool Sharing One VoIP Account Between the FXS and PSTN Lines The FXS (Line 1) and FXO (PSTN Line) can share a single VoIP account if they use different SIP ports. If the service provider allows multiple registration contacts and simultaneous ringing, both lines can register periodically with the service provider. In this case, both lines receive inbound calls to this VoIP account. The PSTN Line should be configured with a sufficiently long answer delay before the call is automatically answered to allow for the function of the PSTN gateway. If the service provider does not allow more than one register contact, the PSTN Line should not register. In this case, only Line 1 rings on the inbound call to this VoIP account because it is the only line registered with the service provider. Line 1 can have the call forwarded to the PSTN Line after a few seconds using the Call-Forward-On-No-Answer feature with gw0 as the forward destination. Similarly, Line 1 can apply Call-Forward-All, Call-Forward-On-Busy, and Call-Forward-Selective feature, and direct the caller to the PSTN-Gateway. Only PIN authentication is allowed when a VoIP caller is forwarded to the PSTN-gateway from Line 1. If HTTP Authentication is used, the caller is not authenticated. Another option when using the Forward-To-GW0 feature is to forward the caller to a specific PSTN number, using the syntax @gw0 in the forward destination. When using this with Call-Forward-Selective, you can develop some interesting applications. For example, you can forward all callers with 408 area code to 14081234567, or all callers with 800 area code to 18005558355 (This is the number for Tell Me). When this syntax is used, authentication is not used and the target PSTN number is automatically dialed by the SPA3102 after the caller is forwarded to gw0. Other Options This section describes other options provided by the SPA3102. It includes the following topics: • PSTN Call to Ring Line 1, page 4-8 Document Version 3.1 Linksys ATA Administrator Guide 4-7