Modifying Bell Paging Schedules in Asterisk

The site that caused me to set up bell paging on our trixbox system also threw me a curveball by having an "alternate" schedule that they needed implemented every Thursday, although occasionally they need to set the "Thursday" schedule on other days of the week. I got tired of manually updating the crontab for these times, so I configured a feature code so that they could override the normally programmed time themselves.

First create a custom context to use as a destination that will run the script that modifies our crontab
edit /etc/asterisk/extensions_custom.conf ad add something like
[ext-belltoggle-custom]
exten => s,1,AGI(toggle-bells.sh)

Next create a custom destination to trigger that context
Custom destination : ext-belltoggle-custom,s,1
Description: Toggle Bells

Then create a Misc Application to trigger our custom destination:
Description: Toggle Bells
Feature Code: *281 (or whatever you like)
Feature Status: Enabled
Destination: Custom Destinations -> Toggle Bells

Create toggle-bells.sh in /var/lib/asterisk/agi-bin with the following

#!/bin/bash

# Consume all variables sent by Asterisk
while read VAR && [ -n ${VAR} ] ; do : ; done

# Answer the call.
echo "ANSWER"
read RESPONSE

# Say the letters of "Hello World"
#echo 'SAY ALPHA "Hello World" ""'
#read RESPONSE

if crontab -l | grep -q "ALTERNATE"; then
  echo "51 * * * * /var/lib/asterisk/bin/freepbx-cron-scheduler.php
1 00 * * 1,2,3,5 /usr/bin/crontab /var/lib/asterisk/scripts/normalbells
1 00 * * 4 /usr/bin/crontab /var/lib/asterisk/scripts/alternatebells
1 00 * * 0,6 /usr/bin/crontab /var/lib/asterisk/scripts/weekendbells
##NORMAL BELLS##
##Put your normal schedule here with lines like the following##
30 08 * * * /usr/sbin/asterisk -rx 'originate Local/8102@ext-paging extension 8103@ext-paging'
" | crontab -

  echo 'EXEC PLAYBACK "custom/NormalBellActivated" ""'
  read RESPONSE

elif crontab -l | grep -q "NORMAL"; then
  echo "51 * * * * /var/lib/asterisk/bin/freepbx-cron-scheduler.php
1 00 * * 1,2,3,5 /usr/bin/crontab /var/lib/asterisk/scripts/normalbells
1 00 * * 4 /usr/bin/crontab /var/lib/asterisk/scripts/alternatebells
1 00 * * 0,6 /usr/bin/crontab /var/lib/asterisk/scripts/weekendbells
##ALTERNATE BELLS##
##Put your alternate schedule here with lines like the following##
35 08 * * * /usr/sbin/asterisk -rx 'originate Local/8102@ext-paging extension 8103@ext-paging'
" | crontab -

  echo 'EXEC PLAYBACK "custom/AlternateBellActivated" ""'
  read RESPONSE

fi

exit 0

Create 3 crontab files in /var/lib/asterisk/scripts/ called normalbells alternatebells and weekendbells that will be sourced to set the schedule to the normal time each day.

They should look identical to what the asterisk user's crontab looks like when it's in one of the modes.

Finally, create two system recordings named NormalBellActivated and AlternateBellActivated that will be used to inform the user which mode they're in.

FreePBX BLF Time Conditions

My previous post was about increasing the number of Call Routing toggles in FreePBX because I thought that was what I would need to do in order to get BLF (Busy Lamp Field) working with the presence feature on our Polycom SoundPoint phones. The reason I wanted to do that was that so users could have an indication if their phone was in "night mode" or not. As it turns out there is a MUCH better way to handle this.

Step 1
In FreePBX, go to Settings -> Advanced Settings and change "Enable Custom Device States" to True

Step 2
In Applications -> Time Conditions, create your Time Condition. You'll notice that by enabling the previous option, you now have a "Generate BLF Hint" checkbox. Be sure to set that to ON, make sure you also set the "Enable Override Code" box to ON. Once you save the Time Condition, make a note of the override code assigned to it (likely something like *270)

Step 3
On your phone, enable the presence feature. For my SoundPoint IP 601, this meant setting         feature.1.enabled="{$feature_1_enabled|1}" in my server.cfg
I had tried to set feature.1.enabled="1" in sip.cfg which I had seen referenced multiple times, however it never seemed to enable the presence feature.

Step 4
Add the extension *270 to the list of watched extensions on your phone. You can provision it via config file, or set up the extension in the local directory on the phone, and while doing so, scroll down to the "Buddy Watch" option and toggle it to "Enabled"

Increasing the number of FreePBX Call Flow Control Options

We're starting to retool our VOIP infrastructure, and consolidate down from 30+ Trixbox servers to a single FreePBX server. One issue with the amalgamation however is that by default, FreePBX only allows you 10 Call Flow Control indexes. Since we have some 30 odd sites, this wouldn't work for us. However, this fantastic blog post: http://sysadminman.net/blog/2013/daynight-aka-call-flow-control-more-than-10-4884 shows you how to increase that to the number of your choosing. I'll repost the gist here.

1. copy /var/www/html/admin/modules/daynight/functions.inc.php to /var/www/html/admin/modules/daynight/functions.inc.php.dist (good to have a backup)
2. edit /var/www/html/admin/modules/daynight/functions.inc.php and find function daynight_get_avail() { (should start around line 258)
3. under global $db; add another line that reads $NUMDAYNIGHT = 99;
4. comment out the section that starts for ($i=0;$i<=9;$i++) { and ends return $list; (since this is PHP, just add // to the start of those lines
5. under the commented out lines, add the following:

         for ($i=0;$i<=($NUMDAYNIGHT-1);$i++) {
                 $n=ceil(log10($NUMDAYNIGHT));
                 $format="%0".$n."d";
                 $j=sprintf($format,$i);
                 if (!in_array($j,$results)) {
                         $list[]=$j;
                 }
         }
         return $list;

The whole block of code from line 258 function daynight_get_avail() { to line 284 } should look like:

function daynight_get_avail() {
        global $db;
        $NUMDAYNIGHT = 99;

        $sql = "SELECT ext FROM daynight ORDER BY ext";
        $results = $db->getCol($sql);
        if(DB::IsError($results)) {
                $results = array();
        }

//      for ($i=0;$i<=9;$i++) {
//              if (!in_array($i,$results)) {
//                      $list[]=$i;
//              }
//      }
//      return $list;

        for ($i=0;$i<=($NUMDAYNIGHT-1);$i++) {
                $n=ceil(log10($NUMDAYNIGHT));
                $format="%0".$n."d";
                $j=sprintf($format,$i);
                if (!in_array($j,$results)) {
                        $list[]=$j;
                }
        }
        return $list;
}

Now if you go to Applications -> Call Flow Control you will have 99 options for Flow Toggles!

Scheduled Switch Reloading

Had this tip passed on to me by an Axia representative when we were provisioning a bunch of changes to our network. if you're making switch configuration changes remotely (something I often have to do because of how remote our sites are) a good idea is to schedule a reboot of the switch in the near future, then make your configuration changes. Then if everything looks good, write your config and cancel the reload. That way if things go bad and you loose connectivity, the switch will reboot with it's old (working) configuration!

For Procurve switches, this might look something like:
reload after 35 (to schedule a reboot in 35 minutes)
and if you want to cancel the reload:
no reload

Bells via Asterisk Paging

As a few of our sites don't have a traditional PA system, and no way to play bell noises to signal class breaks, we decided to use the asterisk paging system to play bell noises through the handsets in each classroom. There are a few different ways of doing this, but here's the solution we came up with

1) Create a paging group with the extensions you want to play the sound (our sites are currently using Trixbox, so this is under the Paging and Intercom section). Let's call that extension XXXX

2) Create a dummy extension to play the bell noise.
This involves editing /etc/asterisk/extensions_custom.conf and creating an extension that just plays the sound and then hangs up. Let's call that extension YYYY. Add the following near the end of the file:

[ext-paging-custom]

exten => YYYY,1,Answer

exten => YYYY,n,Wait(3)

exten => YYYY,n,Background(hello-world)

exten => YYYY,n,HangUp()

Replace hello-world with the name of a sound file in your asterisk system. If the sound takes too long to start, or has already started when the page happens, you'll need to adjust the value for Wait() as well.

3) Create a cron job to make the bells ring. You can use the following command
asterisk -rx 'originate Local/YYYY@ext-paging extension XXXX@ext-paging'
This will originate the page from the YYYY extension, which will play the bell noise and hang up.

It's also not a bad idea, if you're running trixbox or freepbx or similar, to add the YYYY extension to the "custom extensions" (trixbox: PBX -> PBX Settings -> Tools tab -> custom extensions, freepbx: Admin -> Custom extensions) so that you don't accidentally assign extension YYYY.

Syncing Active Directory Groups as Moodle Cohorts

We had a situation that required us to synchronize certain active directory groups with enrollment in a moodle course. The way we accomplished this was to use a moodle userscript that synced active directory groups as cohorts. Then we assigned the cohorts to the course using the "cohort-sync" enrollment type.

The following steps assume you already have moodle LDAP auth configured and are running the /auth/ldap/cli/sync_users.php to sync LDAP users to moodle.

1. Obtain the sync_cohorts.php script from https://tracker.moodle.org/browse/MDL-25011?attachmentOrder=desc and place it in /auth/ldap/cli/

2. Add the following lines to moodle's config.php

$CFG->ldap_group_class='group';
$CFG->ldap_process_nested_groups=1;
$CFG->ldap_real_user_attribute='sAMAccountName';

ldap_group_class - needs to be set to 'group' for active directory in order to match user groups
ldap_process_nested_groups - set this to 1 if you have groups as members of your groups in order to locate the actual users
ldap_real_user_attribute - this is probably whatever you have "User attribute" set to in moodle's LDAP settings. Also note that it is CASE SENSITIVE (that one gave me some trouble until I realized what the issue was).

3. Add the sync_cohorts.php scrip to your webserver user's crontab to be run sometime after the ldap sync_users.php finishes.

4. Add the newly created cohort to your course using the cohort-sync enrollment type.

Converting from Hyper-V using VMWare Converter: Take 2

I ran into another cause of the dreaded “Unable to obtain hardware information” when trying to convert some VMs from a Hyper-V 2012 server. Turns out that VMware Converter will throw this error if the VM is using the newer .vhdx virtual disk format instead of .vhd.

To get around it, convert the disks to .vhd (because Hyper-V server is a core server, I used the PowerShell cmdlet "Convert-VHD".

Power down the VM

Convert the vhdx to vhd using the command: Convert-VHD - Path C:\Path\To\Virtual\Drive\VMname.vhdx -DestinationPath C:\Path\To\Virtual\Drive\VMname.vhd

Reconfigure the VM. Detach the old vhdx drive, attach the vhd drive.

Run converter again.

Presto!