Linksys ATA Administration Guide
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How VoIP-To-PSTN Calls Work
Configuring the PSTN (FXO) Gateway
match one of the VoIP accounts stored on the Linksys ATA device. Each VoIP user account
contains the information listed below.
NOTE:
If Authentication is disabled, a default dial plan is used for all unknown VoIP users.
Two-Stage Dialing
In two-stage dialing, the Linksys ATA device takes the FXO port off-hook but does not
automatically dial any digits after accepting the call. To invoke two-stage dialing, the VoIP caller
should INVITE the PSTN Line without the user-id in the Request-URI or with a user-id that
matches exactly the <
User ID
n
> of the PSTN Line. A different user-id in the Request-URI is
treated as a request for one-stage dialing if one-stage dialing is enabled, or dropped by the
Linksys ATA device (as if no user-id is given) if one-stage dialing is disabled.
NOTE:
If Authentication is disabled, a default dial plan is assigned to all VoIP callers.
HTTP Digest Authentication can be also used for two-stage dialing, as in one-stage dialing. If
using HTTP Digest Authentication or Authentication is disabled, the VoIP caller should hear the
PSTN dial tone right after the call is answered (by a SIP 200 response).
If PIN Authentication is enabled, the VoIP caller is prompted to enter a PIN number after the
Linksys ATA device answers the call. The PIN number must end with a # key. The inter-PIN-digit
timeout is 10 seconds (not configurable). Up to eight VoIP caller PIN numbers can be
configured on the Linksys ATA device. A dial plan can be selected for each PIN number. If the
caller enters a wrong PIN or the Linksys ATA device times out waiting for more PIN digits, the
Linksys ATA device tears down the call immediately with a BYE request.
NOTE:
When the source address of the INVITE is 127.0.0.1, authentication is automatically
disabled because this is a call by the local user. This applies to both one-stage and two-stage
dialing.
The following table lists the parameters used in two-stage dialing.
Parameter
Web Page Description
Values
User ID 1/2/3/4/
5/6/7/8
PSTN Line
The username value.
31-character string
Password 1/2/3/
4/5/6/7/8
PSTN Line
The password value.
31-character string
User 1/2/3/4/5/
6/7/8 DP
PSTN Line
Specifies the dial plan to be used for this VoIP user. If
0, dial plan processing is disabled; the given target
number is dialed to the PSTN as is.
Choice of 0-8
Parameter
Web
Page
Description
Values
VoIP Caller 1/2/3/4/
5/6/7/8 PIN
PSTN
Line
The PIN for VoIP Caller 1, 2, 3, 4, 5, 6, 7, or 8.
31-character string
VoIP Caller 1/2/3/4/
5/6/7/8 DP
PSTN
Line
Specifies which dial plan to be used for this VoIP
caller. If 0, dial plan processing is disabled; the given
target number is dialed to the PSTN as is.
Choice of 1 to 8