Asterisk allows you to utilize a NetBSD machine for telephone conversations. 

To install asterisk do: 
    
    # cd /usr/pkgsrc/comms/asterisk
    # make install
    

To run asterisk during machine start add into _rc.local_ file following: 
    
    /usr/pkg/sbin/asterisk
    

Configuration files of asterisk are located at: 
    
    /usr/pkg/etc/asterisk
    

List of devices which work well with Asterisk under NetBSD: 

  * Asotel 2FXO2FXS 
  * Asotel 6FXO 
  * D-Link DPH-80S (sip) 
  * D-Link DPH-120S 
  * D-Link DVG-2004S 
  * D-Link DVG-3004S 
  * D-Link DVG-2032S 
  * Sipura SPA901 
  * Sipura SPA3102 

List of devices which do not work well: 

  * AddPac AP1100F 8FXO 
  * AudioCodes 8FXO 
  * D-Link DVG-2032S 32FXO 
  * Sipura SPA400 

To register each FXO/FXS device in asterisk you should add it into the _sip.conf_ file as follows: 
    
    [1001]
    type=friend
    host=dynamic
    insecure=yes
    

Where [1001] is the number to call this device. Each device may have the appropriate number. After adding devices into the configuration file do reload configuration: 
    
    #asterisk -r
    CLI> sip reload
    

To enable dialing of registered devices you should create a basic dialing plan and add this dialing plan into the '_extentions.conf_ file. For an example like this: 
    
    exten => _1001, 1, Dial(SIP/$(EXTEN)@1001, 30, S(600))
    

After changing the dialing plan reload the extensions: 
    
    #asterisk -r
    CLI> extensions reload 
    

See also the [asterisk](http://www.asterisk.org) official page.