A PBX is only really useful if you can get calls into it.  Of course, you
can use Asterisk with VoIP calls (SIP, H.323, IAX), but you can also talk
to the real PSTN through various cards.

Supported Hardware is divided into two general groups:  Zaptel devices and 
non-zaptel devices.  The Zaptel compatible hardware supports pseudo-TDM 
conferencing and all call features through chan_zap, whereas non-zaptel 
compatible hardware may have different features.

Zaptel compatible hardware
==========================

-- Linux Support Services, Inc. (Primary author of Asterisk)
        http://www.linux-support.net, http://store.yahoo.com/asteriskpbx

   * Wildcard X100P - Single FXO interface connects to Loopstart phone 
     line

   * Wildcard T400P - Quad T1 interface connects to four T1/PRI 
     interfaces.  Supports RBS and PRI voice and PPP, FR, and HDLC data.

   * Wildcard E400P - Quad E1 interface connects to four E1/PRI (or PRA)
     interfaces.  Supports PRA/PRI, EuroISDN voice and PPP, FR, HDLC data.

Non-zaptel compatible hardware
==============================

-- QuickNet, Inc. 
       http://www.quicknet.net

   * Internet PhoneJack - Single FXS interface.  Supports Linux telephony
     interface.  DSP compression built-in.

   * Internet LineJack - Single FXS or FXO interface.  Supports Linux 
     telephony interface.


Miscellaneous other interfaces
==============================

-- ISDN4Linux
       http://www.isdn4linux.de/

   * Any ISDN terminal adapter supported by isdn4linux should provide
     connectivity.

-- ALSA
       http://www.alsa-project.org

   * Any ALSA compatible full-duplex sound card

-- OSS
       http://www.opensound.com

   * Any OSS compatible full-duplex sound card