\subsection{Introduction}This package contains the mISDN Channel Driver for the Asterisk PBX. Itsupports every mISDN Hardware and provides an interface for asterisk.\subsection{Features}\begin{itemize}\item  NT and TE mode\item  PP and PMP mode\item  BRI and PRI (with BNE1 and BN2E1 Cards)\item  Hardware Bridging\item  DTMF Detection in HW+mISDNdsp\item  Display Messages on Phones (on those that support display msg)\item  app\_SendText\item  HOLD/RETRIEVE/TRANSFER on ISDN Phones : )\item  Screen/ Not Screen User Number\item  EchoCancellation\item  Volume Control\item  Crypting with mISDNdsp (Blowfish)\item  Data (HDLC) callthrough\item  Data Calling (with app\_ptyfork +pppd)\item  Echo cancellation\item  CallDeflection\item Some other\end{itemize}\subsection{Fast Installation Guide}It is easy to install mISDN and mISDNuser. This can be done by:\begin{itemize}     \item You can download latest stable releases from \url{http://www.misdn.org/downloads/}     \item Just fetch the newest head of the GIT (mISDN provect moved from CVS)     In details this process described here: \url{http://www.misdn.org/index.php/GIT}\end{itemize}then compile and install both with:\begin{astlisting}\begin{verbatim}cd mISDN ;make && make install\end{verbatim}\end{astlisting}(you will need at least your kernel headers to compile mISDN).\begin{astlisting}\begin{verbatim}cd mISDNuser ;make && make install\end{verbatim}\end{astlisting}Now you can compile chan\_misdn, just by making asterisk:\begin{astlisting}\begin{verbatim}cd asterisk ;./configure && make && make install\end{verbatim}\end{astlisting}That's all!Follow the instructions in the mISDN Package for how to load the KernelModules. Also install process described in \url{http://www.misdn.org/index.php/Installing_mISDN}\subsection{Pre-Requisites}To compile and install this driver, you'll need at least one mISDN Driver andthe mISDNuser package. Chan\_misdn works with both, the current release versionand the development (svn trunk) version of Asterisk. mISDNuser and mISDN mustbe fetched from cvs.isdn4linux.de.You should use Kernels $>$= 2.6.9\subsection{Configuration}First of all you must configure the mISDN drivers, please follow theinstructions in the mISDN package to do that, the main config file and configscript is:\begin{astlisting}\begin{verbatim}/etc/init.d/misdn-init  and/etc/misdn-init.conf\end{verbatim}\end{astlisting}Now you will want to configure the misdn.conf file which resides in theasterisk config directory (normally /etc/asterisk).\subsubsection{misdn.conf: [general]}The misdn.conf file contains a "general" subsection, and user subsections whichcontain misdn port settings and different Asterisk contexts.In the general subsection you can set options that are not directly portrelated. There is for example the very important debug variable which you canset from the Asterisk cli (command line interface) or in this configurationfile, bigger numbers will lead to more debug output. There's also a tracefileoption, which takes a path+filename where debug output is written to.\subsubsection{misdn.conf: [default] subsection}The default subsection is another special subsection which can contain all theoptions available in the user/port subsections. the user/port subsection inherittheir parameters from the default subsection.\subsubsection{misdn.conf: user/port subsections}The user subsections have names which are unequal to "general". Those subsectionscontain the ports variable which mean the mISDN Ports. Here you can addmultiple ports, comma separated.Espacially for TE-Mode Ports there is a msns option. This option tells thechan\_misdn driver to listen for incoming calls with the given msns, you caninsert a '*' as single msn, which leads in getting every incoming call (if youwant to share on PMP TE S0 with a asterisk and a phone or isdn card you shouldinsert here the msns which you'll like to give the Asterisk).  Finally acontext variable resides in the user subsections, which tells chan\_misdn where tosend incoming calls to in the Asterisk dial plan (extension.conf).\subsubsection{Dial and Options String}The dial string of chan\_misdn got more complex, because we added more features,so the generic dial string looks like:\begin{astlisting}\begin{verbatim}mISDN/<port>[:bchannel]|g:<group>/<extension>[/<OPTIONSSTRING>]The Optionsstring looks Like::<optchar1><OptParam1>:<optchar2><OptParam2>the ":" character is the delimiter.The available Optchars are:  d - Send display text on called phone, text is the optparam  n - don't detect dtmf tones on called channel  h - make digital outgoing call  c - make crypted outgoing call, param is keyindex  e - perform echo cancellation on this channel,      takes taps as arguments (32,64,128,256)  s - send Non Inband DTMF as inband  vr - rxgain control  vt - txgain control\end{verbatim}\end{astlisting}chan\_misdn registers a new dial plan application "misdn\_set\_opt" whenloaded. This application takes the Optionsstring as argument. The Syntax is:\begin{verbatim}misdn_set_opt(<OPTIONSSTRING>)\end{verbatim}When you set options in the dialstring, the options are set in the externalchannel. When you set options with misdn\_set\_opt, they are set in the currentincoming channel. So if you like to use static encryption, the scenario looksas follows:\begin{verbatim}Phone1 --> * Box 1 --> PSTN_TEPSTN_TE --> * Box 2 --> Phone2\end{verbatim}The Encryption must be done on the PSTN sides, so the dialplan on the boxesare:\begin{verbatim}* Box 1:exten => _${CRYPT_PREFIX}X.,1,Dial(mISDN/g:outbound/:c1)* Box 2:exten => ${CRYPT_MSN},1,misdn_set_opt(:c1)exten => ${CRYPT_MSN},2,dial(${PHONE2})\end{verbatim}\subsection{mISDN CLI commands}At the Asterisk cli you can try to type in:\begin{verbatim}misdn <tab> <tab>\end{verbatim}Now you should see the misdn cli commands:\begin{astlisting}\begin{verbatim}- clean  -> pid    (cleans a broken call, use with care, leads often       to a segmentation fault)- send  -> display  (sends a Text Message to a Asterisk channel,       this channel must be an misdn channel)- set  -> debug  (sets debug level)- show  -> config (shows the configuration options)  -> channels (shows the current active misdn channels)  -> channel  (shows details about the given misdn channels)  -> stacks (shows the current ports, their protocols and states)  -> fullstacks (shows the current active and inactive misdn channels)- restart  -> port   (restarts given port (L2 Restart) )- reload    (reloads misdn.conf)\end{verbatim}\end{astlisting}You can only use "misdn send display" when an Asterisk channel is created andisdn is in the correct state. "correct state" means that you have established acall to another phone (mustn't be isdn though).Then you use it like this:misdn send display mISDN/1/101 "Hello World!"where 1 is the Port of the Card where the phone is plugged in, and 101 is themsn (callerid) of the Phone to send the text to.\subsection{mISDN Variables}mISDN Exports/Imports a few Variables:\begin{verbatim}- MISDN_ADDRESS_COMPLETE :  Is either set to 1 from the Provider, or you        can set it to 1 to force a sending complete.\end{verbatim}\subsection{Debugging and sending bug reports}If you encounter problems, you should set up the debugging flag, usuallydebug=2 should be enough. the messages are divided in asterisk and misdnparts.  Misdn Debug messages begin with an 'I', asterisk messages begin withan '*', the rest is clear I think.Please take a trace of the problem and open a report in the Asterisk issuetracker at \url{http://bugs.digium.com} in the "channel drivers" project,"chan\_misdn" category. Read the bug guidelines to make sure youprovide all the information needed.\subsection{Examples}Here are some examples of how to use chan\_misdn in the dialplan(extensions.conf):\begin{astlisting}\begin{verbatim}[globals]OUT_PORT=1 ; The physical Port of the CardOUT_GROUP=ExternE1 ; The Group of Ports defined in misdn.conf[misdnIn]exten => _X.,1,Dial(mISDN/${OUT_PORT}/${EXTEN})exten => _0X.,1,Dial(mISDN/g:${OUT_GROUP}/${EXTEN:1})exten => _1X.,1,Dial(mISDN/g:${OUT_GROUP}/${EXTEN:1}/:dHello)exten => _1X.,1,Dial(mISDN/g:${OUT_GROUP}/${EXTEN:1}/:dHello Test:n)\end{verbatim}\end{astlisting}On the last line, you will notice the last argument (Hello); this is sentas Display Message to the Phone.\subsection{Known Problems}Q: I cannot hear any tone after a successful CONNECT to the other endA: You forgot to load mISDNdsp, which is now needed by chan\_misdn for switchingand dtmf tone detection