Linksys (Sipura) SPA3102 PSTN VoIP Gateway on Mac OS X Leopard with incoming fax detection

A Linksys SPA3102 successfully replaced the Digium FXO an FXS zaptel modules on an Asterisk VoIP home PBX. Part of the migration from a Linux CentOS based system to an Apple Mac OS X 10.5.2 Leopard iMac involved abandoning the PCI Digium boards. The SPA3102 has one FXO and one FXS port. The FXO was connected to the local telephone company line and the FXS was connected to the fax machine. The NVFaxDetect module was added to Asterisk to complete the migration. The NVFaxDetect program can detect fax tones on any Asterisk channel.

First get the latest Linksys firmware for the SPA3102. At this writing it was Version 5.1.7. Below is the configuration used.

Router
Wan Setup
   Remote Management
       Enable WAN Web Server - yes
Lan Setup - Networking Service - Bridge

Voice
System
   System Configuration
       Enable Web Admin Access - yes
 Regional
       Miscellaneous
            Time Zone
                yours
            Daylight Saving Time Rule - edit if needed
Line 1
   NAT Settings
       NAT Mapping Enable - no
    Proxy and Registration
        Proxy - IP address or DNS name
    Outbound Proxy: IP address or DNS name
    Use Outbound Proxy - yes
    Subscriber Information
         Display Name:
         Password:
         Auth ID:
         User ID:
Dial Plan
    Dial Plan: default or (xx.)
PSTN Line
   Proxy and Registration
      Proxy:
      Outbound Proxy:
       Use Outbound Proxy:
    Subscriber Information
        Display Name:
        Password:
        Auth ID:
        User ID:
     Dial Plans
         Dial Plan 1: (xx.)
      Dial Plans
         Dial Plan 8: (S0<:@pbx.localdomain>)
      VoIP-To-PSTN Gateway Setup
           VoIP-To-PSTN Gateway Enable: yes
           Line 1 VoIP Caller DP: none
           VoIP Caller Default DP: 1
       PSTN-To-VoIP Gateway Setup
            PSTN-To-VoIP Gateway Enable: yes
            PSTN Ring Thru Line 1: no
            PSTN Caller Default DP: 8
         FXO Timer Values (sec)
              VoIP Answer Delay: 1
              PSTN Answer Delay: 3
              PSTN Dialing Delay: 1

Retrieve NVFaxDetect source and build it according to the Voip-Info.org guide.

There are some odd delays on incoming calls that might be annoying to some but we hardly use our land line so it doesn't bother us. The delay while NVFaxDetect listens for a fax is quite long at 4 seconds. There are also odd behaviors when dialing outbound calls. Asterisk seems to dial the Linksys which then dials the land line carrier. These annoyances could probably be reduced with some further study.

References

• 2005 copy of app_nv_faxdetect.c at Nerd Vittles
• Voip Info Wiki guide to Using NVFaxDetect on Asterisk 1.4.0
• tribox forums discussing What happened to Newman Telecom
• Voip Info Wiki NV Fax Detectextensions examples for Asterisk
• Linksys SPA 3102 support pages
• LinkSys support page with many good references including a technical manual.