Eric’s Blog

January 15th, 2008 by eric

In order to setup Asterisk to ring multiple phones from the same dialed extension, you will need to create a phantom extension. I accomplished this by doing the following…

Before we go any further, let’s use the following information as true. The extension we want to have ring in multiple places is extension 100. For sanity’s sake, let’s say we want it to ring in 3 places (regardless of the reason). This means that each phone will need its own extension and auth information according to the sip.conf.

First you need to assign each device (phone), its own extension. Let’s give each device the extension of <ext><n>. Therefore our 3 phones will have the extensions of 1001,1002,1003 respectively. Their entries in the sip.conf will look like this:

[1001]
type=peer
context=internal
username=1001
callerid=Eric Lubow <100>
host=dynamic
auth=1001@192.168.1.2
call-limit=100
nat=no
canreinvite=yes
mailbox=100@allstaff
disallow=all
allow=gsm
allow=ulaw
astdb=chan2ext/SIP/1001=1001

[1002]
type=peer
context=internal
username=1002
callerid=Eric Lubow <100>
host=dynamic
auth=1002@192.168.1.2
call-limit=100
nat=no
canreinvite=yes
mailbox=100@allstaff
disallow=all
allow=gsm
allow=ulaw
astdb=chan2ext/SIP/1002=1002

[1003]
type=peer
context=internal
username=1003
callerid=Eric Lubow <100>
host=dynamic
auth=1003@192.168.1.2
call-limit=100
nat=no
canreinvite=yes
mailbox=100@allstaff
disallow=all
allow=gsm
allow=ulaw
astdb=chan2ext/SIP/1003=1003

Next, in your extensions.conf, add the entry to ring all the extensions when the phantom extension is dialed. The Dial() command should now look as follows:

exten => 100,1,Dial(SIP/1001&SIP/1002&SIP1003,18)

A nice thing to do to (in order to not confuse the user) is, in your tftp files, ensure that the label on the phone (each phone) is still the actual extension of the phone that one would dial to get to it. Label the phone elsewhere with your REAL extension to keep track of it.

December 17th, 2007 by eric

Since I know I am not the first (or the last) to make a typo in logrotate and not catch it for a while…someone else must have been in the position of having to delete a lot of files in the same manner. I recently learned that, as usual, there is more than one way to handle it.

To put the situation in context, I basically allowed thousands of mail.* files to be created. These files littered the /var/log/ directory and basically slowed down the entire file system access. I figured out this a number of ways.

The first way was when I tried to do an ls anywhere, it would just hang. My first reaction was to check to see what was eating up the CPU. To do this, I did a top. I noticed that logrotate was hogging all the CPU cycles. Since I know that logrotate basically only operates on one parent directory (by default) /var/log, I headed on over there and did an ls. Once again, it just hung. Then I figured the file system was slow and decided to check out some file system information. The next two commands I ran were df -h and df -i. I ran the df -h to see if we were out of disk space (and yes I lazily use human readable format). I ran the second to check to see how many inodes were in use. (For more information on inodes, check out the wikipedia entry here).

Now that I know the system is short on inodes, I checked out the output of lsof. Now I know that we have some serious problems in the /var/log dir. After some quick investigation, I realized that there were too many mail.* files. How do I get rid of them? Glad you asked… Let’s assume that we want to delete ALL the mail.* files in the /var/log directory.

1) The easiest way is to do it with find:
1a) Using find’s delete command:
[root@eric] /var/log # find ./ -type f -name "mail.*" -delete
or
1b) using find’s exec command with rm:
[root@eric] /var/log # find ./ -type f -name "mail.*" -exec rm -rf '{}' \;
These will work, but either will be slow since they doesn’t do batch execution.

2) A slightly more preferred way is to use bash:
[root@eric] /var/log # for n in mail.*; do rm -v $n; done;
This is a little faster, but will still be relatively slow since there is no batch execution. (Note: The -v in the rm will cause quite a bit of output since it is showing you EVERY file it deletes. Feel free to leave this out if you really screwed up.)

3) The actual preferred method is to use find:
[root@eric] /var/log # find ./ -type f -name "mail.*" | xargs rm -f
I believe this is the preferred method because although it removes the files one at a time, it is more efficient for the file system since it batches it up.

There are certainly other ways to accomplish this task. It can always be done with a Perl one-liner or even using some Perl modules to save some time. These are just a few ideas to point someone in the right direction.

September 25th, 2007 by eric

Here’s another quick little Asterisk recipe that I threw together. It’s a handy because it only takes about 10 minutes to setup and is infinitely useful to the sales types. Just a note, this was done with Asterisk 1.4.8.

I wanted to do a little in AEL just to get a feel for it. It is a little AEL and a little regular extensions.conf type stuff.

The basic way that this CallerID Blocking recipe works is to use the Asterisk DB. An entry with the family of CIDBlock and the key of the dialing users extension will have a value of 1 or 0. The user initially sets their preference to either enabled (1) or disabled (0). When the number gets dialed, the preference gets checked and then the CALLERID(name)/CALLERID(number) values are set accordingly. In order for the user to enable CID Blocking, they need to dial *81. It will stay enabled until they dial *82.

How do we accomplish this? Easy. The sounds come with the asterisk sounds package.

Open up your extensions.conf and add the following lines (to whichever context works for you):

; Enable CallerID Blocking for the dialing extension
exten => *81,1,Set(DB(CIDBlock/${CHANNEL:4:4})=1)
exten => *81,2,Playback(privacy-your-callerid-is)
exten => *81,3,Playback(enabled)
exten => *81,4,Hangup()

; Disable CallerID Blocking for the dialing extension
exten => *82,1,Set(DB(CIDBlock/${CHANNEL:4:4})=0)
exten => *82,2,Playback(privacy-your-callerid-is)
exten => *82,3,Playback(disabled)
exten => *82,4,Hangup()

The last modification that needs to happen is that you have to change the exten that dials out to check the DB and react accordingly. Here is a snippet of mine (with the numbers changed to protect the innocent):

; Outbound calling for 111.222.3456 (my phone number)
exten =>_1NXXNXXXXXX,1,Set(CIDBlock=${DB(CIDBlock/${CHANNEL:4:4})})
exten =>_1NXXNXXXXXX,2,Set(${IF($[${CIDBlock} = 1]?CALLERID(name)=Unavailable:CALLERID(name)=MyCompany)})
exten =>_1NXXNXXXXXX,3,Set(${IF($[${CIDBlock} = 1]?CALLERID(number)=0-1-999:CALLERID(number)=1112223456)})
exten =>_1NXXNXXXXXX,4,DIAL(SIP/provider/${EXTEN},60,tr)
exten =>_1NXXNXXXXXX,5,Hangup

That’s really all it takes to set it up. Quick and handy.

* Note: *81 & *82 are arbitrary number combinations. Adjust to what works for you.

If you’re feeling really frisky, I added this AEL extension to check the status of your CallerID Blocking on *83. For fun, I have also included my *67 script for those who need an idea of how its done. As with almost anything in Asterisk, there are many ways to do it, this is just how I chose to accomplish this.

// Extra's for sending things outbound
context outbound-extra {
   *83 => {
            Playback(privacy-your-callerid-is);
            Set(CIDBlock=${DB(CIDBlock/${CHANNEL:4:4})});
            if(${CIDBlock} == 1) {
                Playback(enabled);
            }
            else {
                Playback(disabled);
            }
            Hangup();
   };

   *67 => {
      // Remove the *67 from the number we are dialing
      Set(dialed_number=${EXTEN:3:11});
      Set(CALLERID(name)=Unavailable):
      Set(CALLERID(number)=0-1-999):
      DIAL(SIP/provider/${dialed_number},60,tr);
      Hangup();
   };
};