[Asterisk-doc] docs introduction.xml,1.4,1.5

blitzrage asterisk-doc@lists.digium.com
Mon, 31 May 2004 02:05:42 +0000


Comments:
Update of /cvsroot/asterisk/docs
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv23188/docs

Modified Files:
	introduction.xml 
Log Message:
blitzrage
- Asterisk is not a turnkey system
- Don't like it?  Change it yourself
- Codecs and Conversions
- Asterisk software: Asterisk, Zaptel, Libpri
- Zaptel Hardware: Overview

Mike Preston
- The Big Picture
- Channels
- Codecs and Conversions
- Protocols
Index: introduction.xml
===================================================================
RCS file: /cvsroot/asterisk/docs/introduction.xml,v
retrieving revision 1.4
retrieving revision 1.5
diff -C2 -d -r1.4 -r1.5
*** introduction.xml	7 May 2004 01:37:42 -0000	1.4
--- introduction.xml	31 May 2004 02:05:36 -0000	1.5
***************
*** 41,49 ****
  			<sect3>
  				<title>Asterisk is not a turnkey system</title>
! 				<para/>
  			</sect3>
  			<sect3>
  				<title>Don't like it?  Change it yourself!</title>
! 				<para/>
  			</sect3>
  			<sect3>
--- 41,72 ----
  			<sect3>
  				<title>Asterisk is not a turnkey system</title>
! 				<para>
! 				The Asterisk PBX system is a complex peice of software.  The learning curve
! 				is very steep and simply reading any single resource will not teach you
! 				everything that Asterisk is capable of.  This resource is an attempt to gather
! 				some of the most common issues that new comers to Asterisk encounter.
! 				Learning how Asterisk works is very much like learning a new programming
! 				language.  Many hours need to be spent with Asterisk in order to understand
! 				how all the configuration files work with each other to control the many
! 				interfaces.  The ability to understand the dialplan is a key concept
! 				that those new to Asterisk need to fully comprehend.  Once this is established
! 				the configuration of the many different kinds of interfaces that you would
! 				like Asterisk to communicate with work in tandem with the dialplan.  This
! 				relationship extends througout Asterisk with many other modules that are
! 				not compiled by default.  The term KISS (Keep It Super Simple) needs to be
! 				applied here with great emphasis.  The mistake many people make when first
! 				discovering Asterisk is that they think they can have a working system
! 				in a couple of hours.  This may be possible once all the concepts are learned,
! 				but few are able to do it their first time out.
! 				</para>
  			</sect3>
  			<sect3>
  				<title>Don't like it?  Change it yourself!</title>
! 				<para>
! 				Asterisk is an open piece of software.  The ability to read the source code
! 				is its power.  Most (if not all) other PBX's are entirely closed source
! 				with only the abilities that have been provided to you.  If something doesn't
! 				work quite the way you would expect it to, you are able to change it.
! 				</para>
  			</sect3>
  			<sect3>
***************
*** 57,73 ****
  		<sect2>
  			<title>The Big Picture</title>
! 			<para/>
  		</sect2>
  		<sect2>
  			<title>Channels</title>
! 			<para/>
  		</sect2>
  		<sect2>
  			<title>Codecs and Conversions</title>
! 			<para/>
  		</sect2>
  		<sect2>
! 			<title>Etc.</title>
! 			<para/>
  		</sect2>
  	</sect1>
--- 80,129 ----
  		<sect2>
  			<title>The Big Picture</title>
! 			<para>
! 			To summerise, a channel generally consists of either an analog signal running
! 			on POTS (or Plain Old Telephone System) or some combination of codec and
! 			signalling protocol, ie. GSM and SIP or ULAW and IAX.
! 			</para>
  		</sect2>
  		<sect2>
  			<title>Channels</title>
! 			<para>
! 			A channel is a voice path equivilent to a phone line between two points.
! 			There are many different ways they can be sent, but can be split into two
! 			groups -- analog and digital.  Analog data is the type of signal that has
! 			been used on the phone system since it was invented.  It can be prone to
! 			noise and echo and can not be sent as is over a digital network in a raw
! 			form.  Digital data consist of ones and zeros.  Analog data as picked up
! 			from a microphone can not be sent as is over a digital network and must
! 			be converted into a series of discrete levels, or quantised, to be able 
! 			to form a digital signal.  Once the data is in a digital state it will
! 			require a fair amount of bandwidth to send as is (64kbits/sec for
! 			uncompressed voice data sampled at 8KHz with 8bits resolution). 
! 			</para>
  		</sect2>
  		<sect2>
  			<title>Codecs and Conversions</title>
! 			<para>
! 			Obviously it is desirable to fit as many calls as possible into a data network.
! 			This is done by encoding it into a form that takes up much less space
! 			using a codec (short for COder/DECoder).  Some examples of these are ulaw,
! 			alaw, gsm, ilbc and g.729.	Codecs determine the sustained data bit rate which 
! 			is required for each	channel.  Different codecs have different advantages but 
! 			are independent of the type of protocol that is used to establish the channel.  
! 			The codec converts the analog voice signal to a digitally encoded one.  The 
! 			quality,	databit rate required and the computational requirements vary from one
! 			codec to the next.
! 			</para>
  		</sect2>
  		<sect2>
! 			<title>Protocols</title>
! 			<para>
! 			Sending data to another phone would be easy if the data found its own way there
! 			and knew what to do at the other end. Unfortunately it doesn't which is
! 			why we use a signalling protocol to encapsulate the voice data.  The common
! 			signalling protocol used today is SIP (an acronym for Session Initiation Protocol).
! 			Others that Asterisk supports include IAX, H.323 and CAPI.  CAPI is a special
! 			case in that it is used within a computer system to deal with ISDN interfaces.							  
! 			</para>
  		</sect2>
  	</sect1>
***************
*** 78,90 ****
  			<sect3>
  				<title>Asterisk (Main PBX &amp; Channels)</title>
! 				<para/>
    			</sect3>
  			<sect3>
  				<title>Zaptel (Drivers for Zaptel Hardware)</title>
! 				<para/>
    			</sect3>
  			<sect3>
  				<title>Libpri (ISDN PRI Drivers for Zaptel)</title>
! 				<para/>
    			</sect3>
  		</sect2>
--- 134,159 ----
  			<sect3>
  				<title>Asterisk (Main PBX &amp; Channels)</title>
! 				<para>
! 				The Asterisk software is what gives a computer system the logic required
! 				to run a PBX system.  IP based channels, dialplans, AGI scripting and 
! 				timing insensitive parts of Asterisk are included.
! 				</para>
    			</sect3>
  			<sect3>
  				<title>Zaptel (Drivers for Zaptel Hardware)</title>
! 				<para>
! 				The drivers for Digium hardware can be obtained from the CVS server.
! 				These will allow you to integrate many types of legecy telephony
! 				equipment such as T1/E1, PSTN, FXO and FXS devices.
! 				</para>
    			</sect3>
  			<sect3>
  				<title>Libpri (ISDN PRI Drivers for Zaptel)</title>
! 				<para>
! 				Libpri will allow Asterisk to work with Primary Rate ISDN interfaces.
! 				It is based on the Bellcore specification SR-NWT-002343 for National
! 				ISDN.  You will need to compile and configure these drivers if you need
! 				Asterisk to speak with an ISDN interface.
! 				</para>
    			</sect3>
  		</sect2>
***************
*** 93,110 ****
  			<sect3>
  				<title>Overview</title>
! 				<para/>
    			</sect3>
  			<sect3>
  				<title>X100P and X101P</title>
!                                 <para>
!                                 The X100P and X101P are Foreign Exchange Office (FXO) devices which
!                                 allow you to connect the Asterisk PBX to a PSTN line.  The only difference
!                                 between an X100P and X101P is a slight difference in chips, but makes no difference
!                                 to it's operation.  The X100P uses a single PCI slot and supports FXS
!                                 Loopstart and "Kewlstart" (Loopstart with far end disconnection supervision).
!                                 With the X100P Asterisk supports both incoming and outgoing calls and
!                                 supports ring detection and remote hangup.
!                                 </para>
!   			</sect3>
  			<sect3>
  				<title>S100U - Single Port FXS USB Interface</title>
--- 162,185 ----
  			<sect3>
  				<title>Overview</title>
! 				<para>
! 				Zaptel hardware is designed and built but Digium, the owners of Asterisk.
! 				The Asterisk PBX system is designed to work with these devices, so are fully
! 				supported.  Drivers are provided to run the devices on a Linux based
! 				operating system.
! 				</para>
    			</sect3>
  			<sect3>
  				<title>X100P and X101P</title>
! 				<para>
! 				The X100P and X101P are Foreign Exchange Office (FXO) devices which
! 				allow you to connect the Asterisk PBX to a PSTN line.  The only difference
! 				between an X100P and X101P is a slight difference in chips, but makes no difference
! 				to it's operation.  The X100P uses a single PCI slot and supports FXS
! 				Loopstart and "Kewlstart" (Loopstart with far end disconnection supervision).
! 				With the X100P Asterisk supports both incoming and outgoing calls and
! 				supports ring detection and remote hangup.
! 				</para>
! 			</sect3>
! 			
  			<sect3>
  				<title>S100U - Single Port FXS USB Interface</title>
***************
*** 116,132 ****
    			</sect3>
  			<sect3>
! 				 <title>TDM400P</title>
!                                 <para>
!                                 The TDM400P is a half-length PCI 2.2 compliant card which allows you to connect
!                                 standard analog telephones and analog lines to a computer.  The card uses small
!                                 modules to activate the 4 ports on the card.  Depending on which daughter card is plugged
!                                 onto the board will determine whether the port acts as an FXO or FXSinterface.  The boards
!                                 are not selectable between modes; the module used determines the type of interface.
!                                 </para>
!                                 <para>
!                                 There is an alternate naming convention used as well to reference the type of modules attached
!                                 to the TDM400P.  This is in the form TDM##B where the first hash is the number of FXS (0-4) interfaces and the
!                                 second hash is the number of FXO (0-4) interfaces.
!                                 </para>
    			</sect3>
  			<sect3>
--- 191,208 ----
    			</sect3>
  			<sect3>
! 				<title>TDM400P</title>
! 				<para>
! 				The TDM400P is a half-length PCI 2.2 compliant card which allows you to connect
! 				standard analog telephones and analog lines to a computer.  The card uses small
! 				modules to activate the 4 ports on the card.  Depending on which daughter card is plugged
! 				onto the board will determine whether the port acts as an FXO or FXSinterface.  The boards
! 				are not selectable between modes; the module used determines the type of interface.
! 				</para>
! 				
! 				<para>
! 				There is an alternate naming convention used as well to reference the type of modules attached
! 				to the TDM400P.  This is in the form TDM##B where the first hash is the number of FXS (0-4) interfaces and the
! 				second hash is the number of FXO (0-4) interfaces.
! 				</para>
    			</sect3>
  			<sect3>
***************
*** 181,184 ****
--- 257,261 ----
    			</sect3>
  		</sect2>
+ 
  		<sect2>
  			<title>Applications</title>