Merge the new Channel Event Logging (CEL) subsystem.

CEL is the new system for logging channel events.  This was inspired after
facing many problems trying to represent what is possible to happen to a call
in Asterisk using CDR records.  For more information on CEL, see the built in
HTML or PDF documentation generated from the files in doc/tex/.

Many thanks to Steve Murphy (murf) and Brian Degenhardt (bmd) for their hard
work developing this code.  Also, thanks to Matt Nicholson (mnicholson) and
Sean Bright (seanbright) for their assistance in the final push to get this
code ready for Asterisk trunk.

Review: https://reviewboard.asterisk.org/r/239/


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@203638 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 958 insertions, 0 deletions

diff --git a/doc/tex/cel-doc.tex b/doc/tex/cel-doc.tex
new file mode 100644
index 000000000..fdda68c37
--- /dev/null
+++ b/doc/tex/cel-doc.tex
@@ -0,0 +1,958 @@
+
+\section{Design Goals}
+
+CEL, or Channel Event Logging, has been written with the hopes that it will help
+solve some of the problems that were difficult to address in CDR records. Some
+difficulties in CDR generation are the fact that the CDR record stores three
+events: the "Start" time, the "Answer" time, and the "End" time. Billing time is
+usually the difference between "Answer" and "End", and total call duration was
+the difference in time from "Start" to "End".  The trouble with this direct and
+simple approach is the fact that calls can be transferred, put on hold,
+conferenced, forwarded, etc. In general, those doing billing applications in
+Asterisk find they have to do all sorts of very creative things to overcome the
+shortcomings of CDR records, often supplementing the CDR records with AGI
+scripts and manager event filters.
+
+The fundamental assumption is that the Channel is the fundamental communication
+object in asterisk, which basically provides a communication channel between two
+communication ports. It makes sense to have an event system aimed at recording
+important events on channels. Each event is attached to a channel, like ANSWER
+or HANGUP. Some events are meant to connect two or more channels, like the
+BRIDGE\_START event. Some events, like BLINDTRANSFER, are initiated by one
+channel, but affect two others. These events use the Peer field, like BRIDGE
+would, to point to the target channel.
+
+The design philosophy of CEL is to generate event data that can grouped together
+to form a billing record. This may not be a simple task, but we hope to provide
+a few different examples that could be used as a basis for those involved in
+this effort.
+
+There are definite parallels between Manager events and CEL events, but there
+are some differences.  Some events that are generated by CEL are not generated
+by the Manager interface (yet). CEL is optimized for databases, and Manager
+events are not. The focus of CEL is billing. The Manager interface is targeted
+to real-time monitoring and control of asterisk.
+
+To give the reader a feel for the complexities involved in billing, please take
+note of the following sequence of events:
+
+Remember that 150, 151, and 152 are all Zap extension numbers, and their
+respective devices are Zap/50, Zap/51, and Zap/52.
+
+152 dials 151; 151 answers.  152 parks 151; 152 hangs up.  150 picks up the park
+(dials 701).  150 and 151 converse.  151 flashes hook; dials 152, talks to 152,
+then 151 flashes hook again for 3-way conference. 151 converses with the other
+two for a while, then hangs up. 150 and 152 keep conversing, then hang up. 150
+hangs up first.(not that it matters).
+
+This sequence of actions will generate the following annotated list of 42 CEL
+events:
+
+{\it Note that the actual CEL events below are in CSV format and do not include
+     the ;;; and text after that which gives a description of what the event
+     represents.}
+
+\begin{astlisting}
+"EV\_CHAN\_START","2007-05-09 12:46:16","fxs.52","152","","","","s","extension","Zap/52-1","","","DOCUMENTATION","","1178736376.3","",""                                   ;;; 152 takes the phone off-hook
+
+"EV\_APP\_START","2007-05-09 12:46:18","fxs.52","152","152","","","151","extension","Zap/52-1","Dial","Zap/51|30|TtWw","DOCUMENTATION","","1178736376.3"                   ;;; 152 finishes dialing 151
+
+"EV\_CHAN\_START","2007-05-09 12:46:18","fxs.51","151","","","","s","extension","Zap/51-1","","","DOCUMENTATION","","1178736378.4","",""                                   ;;; 151 channel created, starts ringing
+
+{\it (151 is ringing)}
+
+"EV\_ANSWER","2007-05-09 12:46:19","","151","152","","","151","extension","Zap/51-1","AppDial","(Outgoing Line)","DOCUMENTATION","","1178736378.4","",""                  ;;; 151 answers
+
+"EV\_ANSWER","2007-05-09 12:46:19","fxs.52","152","152","","","151","extension","Zap/52-1","Dial","Zap/51|30|TtWw","DOCUMENTATION","","1178736376.3","",""                ;;; so does 152 (???)
+
+"EV\_BRIDGE\_START","2007-05-09 12:46:20","fxs.52","152","152","","","151","extension","Zap/52-1","Dial","Zap/51|30|TtWw","DOCUMENTATION","","1178736376.3","","Zap/51-1"  ;;; 152 and 151 are bridged
+
+{\it (151 and 152 are conversing)}
+
+"EV\_BRIDGE\_END","2007-05-09 12:46:25","fxs.52","152","152","","","151","extension","Zap/52-1","Dial","Zap/51|30|TtWw","DOCUMENTATION","","1178736376.3","",""            ;;; after 5 seconds, the bridge ends (152 dials \#700?)
+
+"EV\_BRIDGE\_START","2007-05-09 12:46:25","fxs.52","152","152","","","151","extension","Zap/52-1","Dial","Zap/51|30|TtWw","DOCUMENTATION","","1178736376.3","","Zap/51-1"  ;;; extraneous 0-second bridge?
+
+"EV\_BRIDGE\_END","2007-05-09 12:46:25","fxs.52","152","152","","","151","extension","Zap/52-1","Dial","Zap/51|30|TtWw","DOCUMENTATION","","1178736376.3","",""            ;;;
+
+"EV\_PARK\_START","2007-05-09 12:46:27","","151","152","","","","extension","Zap/51-1","Parked Call","","DOCUMENTATION","","1178736378.4","",""                            ;;; 151 is parked
+
+"EV\_HANGUP","2007-05-09 12:46:29","fxs.52","152","152","","","h","extension","Zap/52-1","","","DOCUMENTATION","","1178736376.3" ,"",""                                   ;;; 152 hangs up 2 sec later
+
+"EV\_CHAN\_END","2007-05-09 12:46:29","fxs.52","152","152","","","h","extension","Zap/52-1","","","DOCUMENTATION","","1178736376.3","",""                                  ;;; 152's channel goes away
+
+{\it (151 is parked and listening to MOH! now, 150 picks up, and dials 701)}
+
+"EV\_CHAN\_START","2007-05-09 12:47:08","fxs.50","150","","","","s","extension","Zap/50-1","","","DOCUMENTATION","","1178736428.5","",""                                   ;;; 150 picks up the phone, dials 701
+
+"EV\_PARK\_END","2007-05-09 12:47:11","","151","152","","","","extension","Zap/51-1","Parked Call","","DOCUMENTATION","","1178736378.4","",""                              ;;; 151's park comes to end
+
+"EV\_ANSWER","2007-05-09 12:47:11","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","",""                     ;;; 150 gets answer (twice)
+
+"EV\_ANSWER","2007-05-09 12:47:12","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","",""                     ;;;
+
+"EV\_BRIDGE\_START","2007-05-09 12:47:12","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"       ;;; bridge begins between 150 and recently parked 151
+
+{\it (150 and 151 are conversing, then 151 hits flash)}
+
+"EV\_CHAN\_START","2007-05-09 12:47:51","fxs.51","151","","","","s","extension","Zap/51-2","","","DOCUMENTATION","","1178736471.6","",""                                   ;;; 39 seconds later, 51-2 channel is created. (151 flashes hook)
+
+"EV\_HOOKFLASH","2007-05-09 12:47:51","","151","152","","","","extension","Zap/51-1","Bridged Call","Zap/50-1","DOCUMENTATION","","1178736378.4","","Zap/51-2"            ;;; a marker to record that 151 flashed the hook
+
+"EV\_BRIDGE\_END","2007-05-09 12:47:51","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"         ;;; bridge ends between 150 and 151
+
+"EV\_BRIDGE\_START","2007-05-09 12:47:51","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"       ;;; 0-second bridge from 150 to ?  150 gets no sound at all
+
+"EV\_BRIDGE\_END","2007-05-09 12:47:51","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"         ;;;
+
+"EV\_BRIDGE\_START","2007-05-09 12:47:51","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"       ;;; bridge start on 150
+
+{\it (151 has dialtone after hitting flash; dials 152)}
+
+"EV\_APP\_START","2007-05-09 12:47:55","fxs.51","151","151","","","152","extension","Zap/51-2","Dial","Zap/52|30|TtWw","DOCUMENTATION","","1178736471.6","",""             ;;; 151-2 dials 152 after 4 seconds
+
+"EV\_CHAN\_START","2007-05-09 12:47:55","fxs.52","152","","","","s","extension","Zap/52-1","","","DOCUMENTATION","","1178736475.7" ,"",""                                  ;;; 152 channel created to ring 152.
+
+{\it (152 ringing)}
+
+"EV\_ANSWER","2007-05-09 12:47:58","","152","151","","","152","extension","Zap/52-1","AppDial","(Outgoing Line)","DOCUMENTATION","","1178736475.7","",""                  ;;; 3 seconds later, 152 answers
+
+"EV\_ANSWER","2007-05-09 12:47:58","fxs.51","151","151","","","152","extension","Zap/51-2","Dial","Zap/52|30|TtWw","DOCUMENTATION","","1178736471.6","",""                ;;;   ... and 151-2 also answers
+
+"EV\_BRIDGE\_START","2007-05-09 12:47:59","fxs.51","151","151","","","152","extension","Zap/51-2","Dial","Zap/52|30|TtWw","DOCUMENTATION","","1178736471.6","","Zap/51-1"  ;;; 1 second later, bridge formed betw. 151-2 and 151
+
+{\it (152 answers, 151 and 152 convering; 150 is listening to silence; 151 hits flash again... to start a 3way)}
+
+"EV\_3WAY\_START","2007-05-09 12:48:58","","151","152","","","","extension","Zap/51-1","Bridged Call","Zap/50-1","DOCUMENTATION","","1178736378.4","","Zap/51-2"           ;;; another hook-flash to begin a 3-way conference
+
+"EV\_BRIDGE\_END","2007-05-09 12:48:58","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"         ;;; -- almost 1 minute later, the bridge ends (151 flashes hook again)
+
+"EV\_BRIDGE\_START","2007-05-09 12:48:58","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"       ;;; 0-second bridge at 150. (3 way conf formed)
+
+"EV\_BRIDGE\_END","2007-05-09 12:48:58","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"         ;;;
+
+"EV\_BRIDGE\_START","2007-05-09 12:48:58","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"       ;;; bridge starts for 150
+
+{\it (3way now, then 151 hangs up.)}
+
+"EV\_BRIDGE\_END","2007-05-09 12:49:26","fxs.50","150","150","","","701","extension","Zap/50-1","ParkedCall","701","DOCUMENTATION","","1178736428.5","","Zap/51-1"         ;;; 28 seconds later, bridge ends
+
+"EV\_HANGUP","2007-05-09 12:49:26","","151","152","","","","extension","Zap/51-1","Bridged Call","Zap/50-1","DOCUMENTATION","","1178736378.4","",""                       ;;; 151 hangs up, leaves 150 and 152 connected
+
+"EV\_CHAN\_END","2007-05-09 12:49:26","","151","152","","","","extension","Zap/51-1","Bridged Call","Zap/50-1","DOCUMENTATION","","1178736378.4","",""                     ;;; 151 channel ends
+
+"EV\_CHAN\_END","2007-05-09 12:49:26","fxs.51","151","151","","","h","extension","Zap/51-2<ZOMBIE>","","","DOCUMENTATION","","1178736428.5","",""                          ;;; 152-2 channel ends (zombie)
+
+{\it (just 150 and 152 now)}
+
+"EV\_BRIDGE\_END","2007-05-09 12:50:13","fxs.50","150","150","","","152","extension","Zap/50-1","Dial","Zap/52|30|TtWw","DOCUMENTATION","","1178736471.6","",""            ;;; 47 sec later, the bridge from 150 to 152 ends
+
+"EV\_HANGUP","2007-05-09 12:50:13","","152","151","","","","extension","Zap/52-1","Bridged Call","Zap/50-1","DOCUMENTATION","","1178736475.7","",""                       ;;; 152 hangs up
+
+"EV\_CHAN\_END","2007-05-09 12:50:13","","152","151","","","","extension","Zap/52-1","Bridged Call","Zap/50-1","DOCUMENTATION","","1178736475.7","",""                     ;;; 152 channel ends
+
+"EV\_HANGUP","2007-05-09 12:50:13","fxs.50","150","150","","","h","extension","Zap/50-1","","","DOCUMENTATION","","1178736471.6","",""                                    ;;; 150 hangs up
+
+"EV\_CHAN\_END","2007-05-09 12:50:13","fxs.50","150","150","","","h","extension","Zap/50-1","","","DOCUMENTATION","","1178736471.6","",""                                  ;;; 150 ends
+\end{astlisting}
+
+In terms of Manager events, the above Events correspond to the following 80
+Manager events:
+
+\begin{astlisting}
+\begin{verbatim}
+Event: Newchannel
+Privilege: call,all
+Channel: Zap/52-1
+State: Rsrvd
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801102.5
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/52-1
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801102.5
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/52-1
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801102.5
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/52-1
+State: Ring
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801102.5
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: 151
+Priority: 1
+Application: Set
+AppData: CDR(myvar)=zingo
+Uniqueid: 1178801102.5
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: 151
+Priority: 2
+Application: Dial
+AppData: Zap/51|30|TtWw
+Uniqueid: 1178801102.5
+
+Event: Newchannel
+Privilege: call,all
+Channel: Zap/51-1
+State: Rsrvd
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801108.6
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/51-1
+State: Ringing
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801108.6
+
+Event: Dial
+Privilege: call,all
+SubEvent: Begin
+Source: Zap/52-1
+Destination: Zap/51-1
+CallerIDNum: 152
+CallerIDName: fxs.52
+SrcUniqueID: 1178801102.5
+DestUniqueID: 1178801108.6
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/51-1
+CallerIDNum: 151
+CallerIDName: <Unknown>
+Uniqueid: 1178801108.6
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/52-1
+State: Ringing
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801102.5
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/51-1
+State: Up
+CallerIDNum: 151
+CallerIDName: <unknown>
+Uniqueid: 1178801108.6
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/52-1
+State: Up
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801102.5
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/52-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801102.5
+Uniqueid2: 1178801108.6
+CallerID1: 152
+CallerID2: 151
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/52-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801102.5
+Uniqueid2: 1178801108.6
+CallerID1: 152
+CallerID2: 151
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/52-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801102.5
+Uniqueid2: 1178801108.6
+CallerID1: 152
+CallerID2: 151
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/52-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801102.5
+Uniqueid2: 1178801108.6
+CallerID1: 152
+CallerID2: 151
+
+Event: ParkedCall
+Privilege: call,all
+Exten: 701
+Channel: Zap/51-1
+From: Zap/52-1
+Timeout: 45
+CallerIDNum: 151
+CallerIDName: <unknown>
+
+Event: Dial
+Privilege: call,all
+SubEvent: End
+Channel: Zap/52-1
+DialStatus: ANSWER
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: h
+Priority: 1
+Application: Goto
+AppData: label1
+Uniqueid: 1178801102.5
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: h
+Priority: 4
+Application: Goto
+AppData: label2
+Uniqueid: 1178801102.5
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: h
+Priority: 2
+Application: NoOp
+AppData: In Hangup! myvar is zingo and accountcode is  billsec is 26 and duration is 40 and end is 2007-05-10 06:45:42.
+Uniqueid: 1178801102.5
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: h
+Priority: 3
+Application: Goto
+AppData: label3
+Uniqueid: 1178801102.5
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/52-1
+Context: extension
+Extension: h
+Priority: 5
+Application: NoOp
+AppData: More Hangup message after hopping around"
+Uniqueid: 1178801102.5
+
+Event: Hangup
+Privilege: call,all
+Channel: Zap/52-1
+Uniqueid: 1178801102.5
+Cause: 16
+Cause-txt: Normal Clearing
+
+Event: Newchannel
+Privilege: call,all
+Channel: Zap/50-1
+State: Rsrvd
+CallerIDNum: 150
+CallerIDName: fxs.50
+Uniqueid: 1178801162.7
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/50-1
+CallerIDNum: 150
+CallerIDName: fxs.50
+Uniqueid: 1178801162.7
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/50-1
+CallerIDNum: 150
+CallerIDName: fxs.50
+Uniqueid: 1178801162.7
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/50-1
+State: Ring
+CallerIDNum: 150
+CallerIDName: fxs.50
+Uniqueid: 1178801162.7
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: 701
+Priority: 1
+Application: ParkedCall
+AppData: 701
+Uniqueid: 1178801162.7
+
+Event: UnParkedCall
+Privilege: call,all
+Exten: 701
+Channel: Zap/51-1
+From: Zap/50-1
+CallerIDNum: 151
+CallerIDName: <unknown>
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/50-1
+State: Up
+CallerIDNum: 150
+CallerIDName: fxs.50
+Uniqueid: 1178801162.7
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Newchannel
+Privilege: call,all
+Channel: Zap/51-2
+State: Rsrvd
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801218.8
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/51-2
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801218.8
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/51-2
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801218.8
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/51-2
+State: Ring
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801218.8
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/51-2
+Context: extension
+Extension: 152
+Priority: 1
+Application: Set
+AppData: CDR(myvar)=zingo
+Uniqueid: 1178801218.8
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/51-2
+Context: extension
+Extension: 152
+Priority: 2
+Application: Dial
+AppData: Zap/52|30|TtWw
+Uniqueid: 1178801218.8
+
+Event: Newchannel
+Privilege: call,all
+Channel: Zap/52-1
+State: Rsrvd
+CallerIDNum: 152
+CallerIDName: fxs.52
+Uniqueid: 1178801223.9
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/52-1
+State: Ringing
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801223.9
+
+Event: Dial
+Privilege: call,all
+SubEvent: Begin
+Source: Zap/51-2
+Destination: Zap/52-1
+CallerIDNum: 151
+CallerIDName: fxs.51
+SrcUniqueID: 1178801218.8
+DestUniqueID: 1178801223.9
+
+Event: Newcallerid
+Privilege: call,all
+Channel: Zap/52-1
+CallerIDNum: 152
+CallerIDName: <Unknown>
+Uniqueid: 1178801223.9
+CID-CallingPres: 0 (Presentation Allowed, Not Screened)
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/51-2
+State: Ringing
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801218.8
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/52-1
+State: Up
+CallerIDNum: 152
+CallerIDName: <unknown>
+Uniqueid: 1178801223.9
+
+Event: Newstate
+Privilege: call,all
+Channel: Zap/51-2
+State: Up
+CallerIDNum: 151
+CallerIDName: fxs.51
+Uniqueid: 1178801218.8
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/51-2
+Channel2: Zap/52-1
+Uniqueid1: 1178801218.8
+Uniqueid2: 1178801223.9
+CallerID1: 151
+CallerID2: 152
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Link
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/51-1
+Uniqueid1: 1178801162.7
+Uniqueid2: 1178801108.6
+CallerID1: 150
+CallerID2: 151
+
+Event: Hangup
+Privilege: call,all
+Channel: Zap/51-1
+Uniqueid: 1178801108.6
+Cause: 16
+Cause-txt: Normal Clearing
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 1
+Application: Goto
+AppData: label1
+Uniqueid: 1178801162.7
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 4
+Application: Goto
+AppData: label2
+Uniqueid: 1178801162.7
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 2
+Application: NoOp
+AppData: In Hangup! myvar is  and accountcode is  billsec is 0 and duration is 0 and end is 2007-05-10 06:48:37.
+Uniqueid: 1178801162.7
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 3
+Application: Goto
+AppData: label3
+Uniqueid: 1178801162.7
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 5
+Application: NoOp
+AppData: More Hangup message after hopping around"
+Uniqueid: 1178801162.7
+
+Event: Masquerade
+Privilege: call,all
+Clone: Zap/50-1
+CloneState: Up
+Original: Zap/51-2
+OriginalState: Up
+
+Event: Rename
+Privilege: call,all
+Oldname: Zap/50-1
+Newname: Zap/50-1<MASQ>
+Uniqueid: 1178801162.7
+
+Event: Rename
+Privilege: call,all
+Oldname: Zap/51-2
+Newname: Zap/50-1
+Uniqueid: 1178801218.8
+
+Event: Rename
+Privilege: call,all
+Oldname: Zap/50-1<MASQ>
+Newname: Zap/51-2<ZOMBIE>
+Uniqueid: 1178801162.7
+
+Event: Hangup
+Privilege: call,all
+Channel: Zap/51-2<ZOMBIE>
+Uniqueid: 1178801162.7
+Cause: 0
+Cause-txt: Unknown
+
+Event: Unlink
+Privilege: call,all
+Channel1: Zap/50-1
+Channel2: Zap/52-1
+Uniqueid1: 1178801218.8
+Uniqueid2: 1178801223.9
+CallerID1: 150
+CallerID2: 152
+
+Event: Hangup
+Privilege: call,all
+Channel: Zap/52-1
+Uniqueid: 1178801223.9
+Cause: 16
+Cause-txt: Normal Clearing
+
+Event: Dial
+Privilege: call,all
+SubEvent: End
+Channel: Zap/50-1
+DialStatus: ANSWER
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 1
+Application: Goto
+AppData: label1
+Uniqueid: 1178801218.8
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 4
+Application: Goto
+AppData: label2
+Uniqueid: 1178801218.8
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 2
+Application: NoOp
+AppData: In Hangup! myvar is  and accountcode is  billsec is 90 and duration is 94 and end is 2007-05-10 06:48:37.
+Uniqueid: 1178801218.8
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 3
+Application: Goto
+AppData: label3
+Uniqueid: 1178801218.8
+
+Event: Newexten
+Privilege: call,all
+Channel: Zap/50-1
+Context: extension
+Extension: h
+Priority: 5
+Application: NoOp
+AppData: More Hangup message after hopping around"
+Uniqueid: 1178801218.8
+
+Event: Hangup
+Privilege: call,all
+Channel: Zap/50-1
+Uniqueid: 1178801218.8
+Cause: 16
+Cause-txt: Normal Clearing
+\end{verbatim}
+\end{astlisting}
+
+And, humorously enough, the above 80 manager events, or 42 CEL events,
+correspond to the following two CDR records (at the moment!):
+
+\begin{astlisting}
+""fxs.52" <152>","152","h","extension","Zap/52-1","Zap/51-1","NoOp","More Hangup message after hopping around"","2007-05-09 17:35:56","2007-05-09 17:36:20","2007-05-09 17:36:36","40","16","ANSWERED","DOCUMENTATION","","1178753756.0",""
+
+""fxs.50" <150>","150","152","extension","Zap/50-1","Zap/51-1","NoOp","More Hangup message after hopping around"","2007-05-09 17:37:59","2007-05-09 17:38:06","2007-05-09 17:39:11","72","65","ANSWERED","DOCUMENTATION","","1178753871.3",""
+\end{astlisting}
+
+
+\section{Events \& Fields}
+
+While CDRs and the Manager are basically both event tracking mechanisms, CEL
+tries to track only those events that might pertain to billing issues.
+
+See table~\ref{event_table} for a list of events raised by CEL and
+table~\ref{field_table} for the list of fields passed for each CEL event.
+
+\begin{table}[h]
+  \begin{tabular}{ | l | p{10cm} | }
+    \hline
+    Event            & Description                                                               \\ \hline \hline
+    CHAN\_START      & The time a channel was created                                            \\ \hline
+    CHAN\_END        & The time a channel was terminated                                         \\ \hline
+    ANSWER           & The time a channel was answered (ie, phone taken off-hook, etc)           \\ \hline
+    HANGUP           & The time at which a hangup occurred.                                      \\ \hline
+    CONF\_ENTER      & The time a channel was connected into a conference room                   \\ \hline
+    CONF\_EXIT       & The time a channel was removed from a conference room                     \\ \hline
+    CONF\_START      & The time the first person enters a conference                             \\ \hline
+    CONF\_END        & The time the last person left a conf (and turned out the lights?)         \\ \hline
+    APP\_START       & The time a tracked application was started                                \\ \hline
+    APP\_END         & the time a tracked application ended                                      \\ \hline
+    PARK\_START      & The time a call was parked                                                \\ \hline
+    PARK\_END        & unpark event                                                              \\ \hline
+    BRIDGE\_START    & The time a bridge is started                                              \\ \hline
+    BRIDGE\_END      & The time a bridge is ended                                                \\ \hline
+    3WAY\_START      & When a 3-way conf starts (usually via attended xfer)                      \\ \hline
+    3WAY\_END        & When one or all exit a 3-way conf                                         \\ \hline
+    BLINDTRANSFER    & When a blind transfer is initiated                                        \\ \hline
+    ATTENDEDTRANSFER & When an attended transfer is initiated                                    \\ \hline
+    TRANSFER         & Generic transfer initiated; not used yet...?                              \\ \hline
+    HOOKFLASH        & So far, when a hookflash event occurs on a Zap interface                  \\ \hline
+    USER\_EVENT      & these are triggered from the dialplan, and have a name given by the user. \\
+    \hline
+  \end{tabular}
+  \caption{List of CEL Events}
+  \label{event_table}
+\end{table}
+
+\begin{table}[h]
+  \begin{tabular}{ | l | p{10cm} | }
+    \hline
+    Field         & Description                                                                \\ \hline \hline
+    eventtype     & The name of the event; see the above list; each is prefixed with "EV\_".   \\ \hline
+    eventtime     & The time the event happened                                                \\ \hline
+    cidname       & CID name field                                                             \\ \hline
+    cidnum        & CID number field                                                           \\ \hline
+    cidani        & CID ANI field                                                              \\ \hline
+    cidrdnis      & CID RDNIS field                                                            \\ \hline
+    ciddnid       & CID DNID field                                                             \\ \hline
+    exten         & The extension in the dialplan                                              \\ \hline
+    context       & The context in the dialplan                                                \\ \hline
+    channame      & The name assigned to the channel in which the event took place             \\ \hline
+    appname       & The name of the current application                                        \\ \hline
+    appdata       & The arguments that will be handed to that application                      \\ \hline
+    amaflags      & The AMA flags associated with the event; user assignable.                  \\ \hline
+    accountcode   & A user assigned datum (string)                                             \\ \hline
+    uniqueid      & Each Channel instance gets a unique ID associated with it.                 \\ \hline
+    userfield     & A user assigned datum (string)                                             \\ \hline
+    linkedid      & the per-call id, spans several events, possibly.                           \\ \hline
+    peer          & For bridge or other 2-channel events, this would be the other channel name \\
+    \hline
+  \end{tabular}
+  \caption{List of CEL Event Fields}
+  \label{field_table}
+\end{table}
+
+\section{Applications \& Functions}
+
+\subsection{CEL Function}
+
+**** THIS IS NO LONGER TRUE.  REWRITE. ****
+
+The CEL function parallels the CDR function, for fetching values from the
+channel or event.  It has some notable notable differences, though! For
+instance, CEL data is not stored on the channel. Well, not much of it, anyway!
+You can use the CEL function to set the amaflags, accountcode, and userfield,
+which are stored on the channel.
+
+Channel variables are not available for reading from the CEL function, nor can
+any variable name other than what's in the list, be set. CDRs have a structure
+attached to the channel, where the CDR function could access the values stored
+there, or set the values there. CDRs could store their own variable lists, but
+CEL has no such storage. There is no reason to store any event information, as
+they are immediately output to the various backends at the time they are
+generated.
+
+See the description for the CEL function from the CLI: core show function CEL
+
+Here is a list of all the available channel field names:
+\begin{verbatim}
+  cidname       userfield
+  cidnum        amaflags
+  cidani        cidrdnis
+  ciddnid       appdata
+  exten         accountcode
+  context       uniqueid
+  channame      appname
+  peer          eventtime
+  eventtype
+\end{verbatim}
+
+\subsection{CELGenUserEvent Application}
+
+This application allows the dialplan to insert custom events into the event
+stream.
+
+For more information, in the CLI, type: core show application CELGenUserEvent
+
+Its arguments take this format:
+
+\begin{verbatim}
+  CELGenUserEvent(eventname)
+\end{verbatim}
+
+Please note that there is no restrictions on the name supplied. If it happens to
+match a standard CEL event name, it will look like that event was
+generated. This could be a blessing or a curse!
+
+\section{Configuration Files}
+
+\begin{itemize}
+\item cel.conf
+\end{itemize}
+
+\section{Generating Billing Information}
+
+*** This is the Next Big Task ***
+
+