Linksys RTP300 User Guide - Page 81

Configuring the PSTN (FXO) Gateway Other Options Other Options This section describes other options provided by the Linksys ATA device. It includes the following topics: • "PSTN Call to Ring Line 1" section on page 81 • "Symmetric RTP" section on page 81 • "Call Progress Tones" section on page 81 PSTN Call to Ring Line 1 This feature allows a PSTN caller to ring Line 1. When the PSTN line rings, the PSTN Line makes a local VoIP call to Line 1. If Line 1 is busy, it stops. After a given number of rings, the VoIP gateway picks up the call. Symmetric RTP The Symmetric RTP parameter is used to send audio RTP to the source IP and port of the inbound RTP packets. This facilitates NAT traversal. The following table lists symmetric RTP parameters. Parameter Symmetric RTP Symmetric RTP Web Page Description Values Line 1 Enable symmetric RTP operation. If enabled, the Linksys ATA device sends RTP packets to the source address of the last received valid inbound RTP packet. If disabled, the Linksys ATA device sends RTP to the destination as indicated in the inbound SDP. Yes or No The default is yes. PSTN Line Same as above for the PSTN line. Yes or No The default is yes. Call Progress Tones The ATA has configurable call progress tones. Call progress tones are generated locally on the ATA, so an end user is advised of status (such as ringback). Parameters for each type of tone (for instance a dial tone played back to an end user) may include: • number of frequency components • frequency and amplitude of each component • cadence information. When one VoIP account is shared between the FXS and PSTN Lines, the following parameters are recommended to be set. See the Regional page in the "Linksys ATA Voice Field Reference," on page 94 for these and other call progress tone parameters. Linksys ATA Administration Guide 81