Month: November 2012

Why Asterisk-based GUI software should make better use of regular expressions

 

Important
This is an edited version of a post that originally appeared on a blog called The Michigan Telephone Blog, which was written by a friend before he decided to stop blogging. It is reposted with his permission. Comments dated before the year 2013 were originally posted to his blog.

Having recently discovered that Asterisk supports regular expressions (with some limitations), I got to wondering why the FreePBX-based GUI’s don’t make better use of them.  For example, in FreePBX, Trixbox, Elastix, etc., the Outbound Route pages all support entering patterns that are then directly used in Asterisk dialplans, in a most inefficient manner.  Let me give you an example.  Let’s say you have created an Outbound Route for toll-free calls, and in the “Dial Patterns that will use this Route” section you have entered these patterns:

1800NXXXXXX
1844NXXXXXX
1855NXXXXXX
1866NXXXXXX
1877NXXXXXX
1888NXXXXXX
800NXXXXXX
844NXXXXXX
855NXXXXXX
866NXXXXXX
877NXXXXXX
888NXXXXXX

Let’s further say that you have specified three trunks in the “Trunk Sequence for Matched Routes” section (this is actually conservative given that there are a number of ways you can route toll-free calls for free).  Anyway, this is an actual representative context that would be generated in extensions_additional.conf:

[outrt-5] ; TollFree
include => outrt-5-custom
exten => _1800NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _1800NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _1800NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _1800NXXXXXX,n,Set(_NODEST=)
exten => _1800NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _1800NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _1800NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _1800NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _1800NXXXXXX,n,Macro(outisbusy,)
exten => _1844NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _1844NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _1844NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _1844NXXXXXX,n,Set(_NODEST=)
exten => _1844NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _1844NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _1844NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _1844NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _1844NXXXXXX,n,Macro(outisbusy,)
exten => _1855NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _1855NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _1855NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _1855NXXXXXX,n,Set(_NODEST=)
exten => _1855NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _1855NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _1855NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _1855NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _1855NXXXXXX,n,Macro(outisbusy,)
exten => _1866NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _1866NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _1866NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _1866NXXXXXX,n,Set(_NODEST=)
exten => _1866NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _1866NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _1866NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _1866NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _1866NXXXXXX,n,Macro(outisbusy,)
exten => _1877NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _1877NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _1877NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _1877NXXXXXX,n,Set(_NODEST=)
exten => _1877NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _1877NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _1877NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _1877NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _1877NXXXXXX,n,Macro(outisbusy,)
exten => _1888NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _1888NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _1888NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _1888NXXXXXX,n,Set(_NODEST=)
exten => _1888NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _1888NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _1888NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _1888NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _1888NXXXXXX,n,Macro(outisbusy,)
exten => _800NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _800NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _800NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _800NXXXXXX,n,Set(_NODEST=)
exten => _800NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _800NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _800NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _800NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _800NXXXXXX,n,Macro(outisbusy,)
exten => _844NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _844NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _844NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _844NXXXXXX,n,Set(_NODEST=)
exten => _844NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _844NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _844NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _844NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _844NXXXXXX,n,Macro(outisbusy,)
exten => _855NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _855NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _855NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _855NXXXXXX,n,Set(_NODEST=)
exten => _855NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _855NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _855NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _855NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _855NXXXXXX,n,Macro(outisbusy,)
exten => _866NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _866NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _866NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _866NXXXXXX,n,Set(_NODEST=)
exten => _866NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _866NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _866NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _866NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _866NXXXXXX,n,Macro(outisbusy,)
exten => _877NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _877NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _877NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _877NXXXXXX,n,Set(_NODEST=)
exten => _877NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _877NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _877NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _877NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _877NXXXXXX,n,Macro(outisbusy,)
exten => _888NXXXXXX,1,Macro(user-callerid,SKIPTTL,)
exten => _888NXXXXXX,n,Noop(Calling Out Route: TollFree)
exten => _888NXXXXXX,n,Set(MOHCLASS=${IF($[“${MOHCLASS}”=””]?default:${MOHCLASS})})
exten => _888NXXXXXX,n,Set(_NODEST=)
exten => _888NXXXXXX,n,Macro(record-enable,${AMPUSER},OUT,)
exten => _888NXXXXXX,n,Macro(dialout-trunk,7,${EXTEN},)
exten => _888NXXXXXX,n,Macro(dialout-trunk,10,${EXTEN},)
exten => _888NXXXXXX,n,Macro(dialout-trunk,8,${EXTEN},)
exten => _888NXXXXXX,n,Macro(outisbusy,)

; end of [outrt-5]

That is 112 lines of dialplan generated by only 12 lines of pattern in the Outbound Route and three trunk selections.  If you have more patterns and/or more trunks, the generated dialplan can grow MUCH larger.  At one point I had a dialplan so large that whenever I did an “orange bar” reload, it took two to three minutes to finish reloading.  Clearly, there is something wrong here.

Now, let’s suppose that instead of, or better yet, in addition to the current Outbound Route pages, we had pages called “Outbound Route – Regular Expression”.  It would eliminate the “Dial Patterns that will use this Route” section, replacing it with a “Regular Expression to select this Route” text box, and it would also have a text box that says “Extensions allowed to use this route (separated by the | character – RegEx patterns may be used).

Let’s say that the contents of the first text box are ^1?8(00|44|55|66|77|88)[2-9][0-9]{6}$ and are stored in variable string1. And let’s say that the contents of the second text box are 10[0-4]X|106[5-8] (specifying that extensions 1000-1049 and 1065-1068 may use this route) and are stored in string 2. Assuming that the part of the dialplan that processes this were in some kind of macro, and the called number is in the variable OUTNUM, you could perhaps do something like this:

exten => s,n,ExecIf($[${REGEX(“${string2}” ${CALLERID(num)})} != 1]?MacroExit())
exten => s,n,ExecIf($[${REGEX(“${string1}” ${OUTNUM})} != 1]?MacroExit())
exten => s,n,Macro(dialout-trunk,7,${OUTNUM},)
exten => s,n,Macro(dialout-trunk,10,${OUTNUM},)
exten => s,n,Macro(dialout-trunk,8,${OUTNUM},)
exten => s,n,Macro(outisbusy,)

The first line bails out of the macro if the Caller ID doesn’t match one of the permitted extensions (this would assume you by default use a regex that matches any extension on your system, for example ^[0-9]{4}$ would match any 4 digit extension number. If you don’t assume this, then you’d need an extra bit of code to skip a null value in string2).

The second line bails if the called number doesn’t match the pattern in string1.

If the called number does match on the regular expression for this route, and the call is from a permitted extension, then the three trunks are tried. Note that now you only need to list each of the three trunks once.

Granted this doesn’t account for every line in the original context, but the other lines could also be transferred into the macro, with a bit of thought. Wouldn’t this be simpler for those who know how to use regular expressions? And, it has the potential to generate MUCH shorter dialplans.

Those who understand the power of regular expressions and who have long or complicated dialplans would appreciate the ability to use regular expressions!  If anyone implements this, don’t be stingy with the maximum string length in the Regular Expression text boxes; I guarantee you that 256 characters is not enough, and neither is 1,024 characters! At a MINIMUM I would say that you need to allow a 4,096 character (4K) regular expression, and while I personally can’t conceive of anyone exceeding that, my bet is that sooner or later someone will.  Remember, you are potentially saving a whole bunch of memory and drive space by allowing regular expressions, so you don’t have to be miserly on the space allotted for the expressions themselves.

How to send various types of notifications on an incoming call in FreePBX

Important
This is an edited version of a post that originally appeared on a blog called The Michigan Telephone Blog, which was written by a friend before he decided to stop blogging. It is reposted with his permission. Comments dated before the year 2013 were originally posted to his blog.

PLEASE NOTE: When you look at examples in this article, be aware that WordPress has a nasty habit of changing quotation marks to “prettified” quotes, which WILL NOT WORK. So, unfortunately, if you copy an example line or code block, you may need to go through and change the quotation marks back to the “real” quotes that most software understands. I get SO sick and tired of WordPress changing my articles on me!

Every so often I’ve had someone ask if they could be sent some sort of notification whenever they get an incoming call. It is, although it will send a notification on any incoming call, not just a missed one (if you only want notifications of missed calls, look toward the bottom of this article). The basic technique is as follows:

First, create or edit a Follow-Me for the user’s extension. Let’s say the extension number is 1122. In the Follow-Me, add a line that looks like this:

****1122#

Note you can use about anything in place **** followed by the extension number and # sign — only the trailing # must be there — but I do it that way so I can keep track of what’s going on.  If you are creating the Follow-Me for the first time, be sure to also put your actual extension number in the Follow-Me list (with NO trailing # sign), and check the other Follow-Me options to make sure that they are what you want (for example, that the “Destination if no answer” is your voicemail, if that’s what you want).

Next, in /etc/asterisk/extensions_custom.conf, find the [from-internal-custom] context (it’s right at the top of the file) and add lines similar to the ones shown below to the bottom of that context. Again, we are using 1122 as the extension, but replace it with the actual extension number:

Note that some of these examples depend on certain other software being present. Also, the FIRST line in each sequence must have the line number 1, but if you use more than one of these for an extension, replace the 1 with n in subsequent lines.

To send an e-mail or SMS message (the mail command must function properly from the Linux command prompt for this to work):

exten => ****1122,1,TrySystem(echo "Call from ${CALLERID(name)} at ${CALLERID(number)} received ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)}" | mail 9995559999@yourcarrier.com)

Replace 9995559999@yourcarrier.com with the e-mail address (which could be an e-mail to SMS gateway – most wireless carriers have one. Just search for “Email to SMS Gateway” and add your carrier’s name to the search, and you should find the format to use).  You can use “System” or “TrySystem” in the line above, the difference being that TrySystem is non-blocking, so the call should not be delayed if the process of sending the e-mail bogs things down.

An alternative way to send a SMS message in the USA and Canada is to use the free service described in the article, Send an SMS Text Message from the Command Line. You can use this even if you don’t have outgoing email configured on your server:

exten => ****1122,1,TrySystem(curl http://textbelt.com/text -d number=9995559999 -d "message=Call from ${CALLERID(name)} at ${CALLERID(number)} received ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)}")

Replace 9995559999 with the destination number.

To send an instant message using the XMPP/Jabber protocol — for this to work /etc/asterisk/xmpp_custom.conf (/etc/asterisk/jabber.conf in older versions of FreePBX) must be configured correctly, and there must NOT be a noload => res_jabber.so statement in modules.conf:

exten => ****1122,1,JabberSend(asterisk,username@gmail.com,Call from ${CALLERID(name)} at ${CALLERID(number)} received ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)})

In the above, asterisk is the account context in xmpp_custom.conf or jabber.conf, and username@gmail.com is the address of the XMPP/Jabber user you want to send the IM to (in this case we assume you and the user are on Google Chat, but you could use any other XMPP/Jabber-based IM service, including a local XMPP/Jabber server set up with Prosody or Openfire or similar software. EDIT: If you are running FreePBX on a Raspberry Pi, see this article and this thread for information on setting up a Prosody server).

If you have XBMC running on a system on your local network, you could use a line such as this to send notifications to it (EDITED to include Kodi Leia):

In Eden and other Pre-Frodo versions:

exten => ****1122,1,TrySystem(wget -b -O /dev/null -o /dev/null "http://192.168.0.234:8080/xbmcCmds/xbmcHttp?command=ExecBuiltIn&parameter=XBMC.Notification(Call%20from%20%22${URIENCODE(${CALLERID(name)})}%22%2C${CALLERID(number)}%20calling%20extension%2C15000%2C%2Fhome%2Fusername%2Fphone.png)")

In Frodo through Krypton:

exten => ****1122,1,TrySystem(wget -b -O /dev/null -o /dev/null "http://192.168.0.234:8080/jsonrpc?request={%22jsonrpc%22:%222.0%22,%22method%22:%22GUI.ShowNotification%22,%22params%22:{%22title%22:%22Call%20from%20${URIENCODE(${CALLERID(name)})}%22,%22message%22:%22${CALLERID(number)}%20calling%20extension%22,%22displaytime%22:15000,%22image%22:%22%2Fhome%2Fusername%2Fphone.png%22},%22id%22:1}")

In Leia and probably later versions, until they decide to change it again:

exten => ****1122,1,TrySystem(curl -X POST -H "Content-Type: application/json" -d '{"jsonrpc":"2.0","method":"GUI.ShowNotification","params":{"title":"Call from ${CALLERID(name)}","message":"${CALLERID(number)} calling extension","displaytime":15000,"image":"/home/username/phone.png"},"id":0}' http://192.168.0.234:8080/jsonrpc)

Note that each of the above is a single long line, and to see either line in its entirety you will need to copy and paste it to a text editor. The above examples assume that XBMC is configured to allow control via a Web interface, at a fixed IP address and port (192.168.0.234 port 8080 in this example). Phone icon - right click and copy imageIf you happen to still have a Linux version of Boxee, the Eden version line might also work with it, perhaps with a bit of tweaking.  I have no idea if it would work (with appropriate modification) with any other standalone home theater PC equipment.  You will likely need to replace username with the user’s name, extension with the called extension’s number, and change the icon path to wherever you put the phone.png file (which is an icon you need to supply, such as the one at the right). Note that the icon path requires %2F in place of forward slashes in pre-Leia versions (therefore %2Fhome%2Fusername%2Fphone.png really means /home/username/phone.png) and this refers to the icon directory and filename — if you choose not to use an icon then leave out this part, depending on your Kodi version:

Eden and prior: %2C%2Fhome%2Fusername%2Fphone.png
Frodo through Krypton: ,%22image%22:%22%2Fhome%2Fusername%2Fphone.png%22
Leia (and beyond?): ,"image":"/home/username/phone.png"

Note the comma at the start; it must be included in the deleted section).  By the way, if you are wondering why it had to be changed again for Kodi Leia, see this thread in the Kodi forum.

If you want to receive Caller ID popup notifications on your computer, see A Perl script to send Caller ID popups from Asterisk to computers running Notify OSD (such as Ubuntu Linux) or any command-line invoked notification system and/or A Perl script to send Caller ID popups from Asterisk to computers running Growl under OS X on a Mac or Growl for Windows.  These articles are a bit dated and may not be fully compatible with some of the newer notification methods in use (such as the Mountain Lion Notification Center in OS X 10.8) but since I don’t have a computer running Mountain Lion, someone else will have to figure that out.  An application such as Hiss, Bark, or Mountain Growl may be helpful in that situation.

After using the any of above lines (and, again, remember to change the line number from 1 to n on any lines after the first), you may want to include a statement like this:

exten => ****1122,n,NoCDR()

That should prevent Asterisk from creating a separate, usually unwanted CDR entry for the ****(extension number) call.  There will still be a CDR record created for the actual call. EDIT: Actually, if you are going to use this, you probably should make it line 1, and move it above the other ****(extension number) lines, so that the CDR record is not saved even if the call gets disconnected in the middle of sending the notification. EDIT 2: In recent Asterisk versions NoCDR() has been deprecated and replaced by CDR_PROP(disable) so be sure to make that change if you are getting BUSY lines in the CDR when this runs.

Finally, to end this part of the context, you need to include a statement that ends the call in a “not completed” state, so that any other extensions in the Follow-Me will be called.  A couple of possibilities are:

exten => ****1122,n,Congestion
exten => ****1122,n,Busy

Use one and if it doesn’t work as expected, try the other. On my system it appears either will work. Remember that you must do a configuration reload in FreePBX before any of your changes to extensions_custom.conf will take effect!

One reason you may want to do instant message or SMS notifications is if you are forwarding calls via a trunk that does not preserve the original caller’s Caller ID.  If you were forwarding the call to a smart phone (perhaps one that also has a Jabber client running), you could deliver the original caller’s name and number to the phone via instant message or SMS.  It may or may not arrive in time for you to make a decision on whether to answer the call, but if you chose not to answer you’d at least know within a few seconds to a few minutes who the call was from, and you could decide whether to call them back.

If you have figured out any neat tricks to do other types of notifications, or if you know of a way to send a notification only when a call was not answered, feel free to leave a comment.

EDIT: At one time this page showed a method for sending SMS notifications using Google Voice rather than an e-mail to SMS gateway. Unfortunately it appears that the unofficial API that was used by such applications is no longer functional. If you know of a way to send a SMS message from a Linux command prompt using Google Voice that is currently working, please leave a message in the comments!

EDIT: I did think of a couple of techniques that might work for sending a notification only if the call is “missed” — the first is a bit of a hack, and has a serious limitation in that if the caller hangs up prior to the call going to voicemail, no notification would be sent (which might or might not be what you want). Basically, you would create (or modify) a Follow-Me as described above, but don’t put the ****extension# line in it. Instead of making the “Destination if no answer” your voicemail (for example), you would point it to a Ring Group that you have created, and in that Ring Group you would place the ****extension# line, and make the “Destination if no answer” of the ring group your voicemail. So the Follow-Me would ring your extension(s) for the number of seconds in the “Ring Time” setting, but if that time expires and no one answers, the call would be sent to the Ring Group where the only “extensions” would be your ****, which would do their thing and immediately return a “busy” or “congestion”. Since there are no other extensions to try, the Ring Group should immediately pass the call on to its “Destination if no answer”, which would most likely be your voicemail.

I haven’t tested this but I see no reason why it would not work, and in that case the notification would be sent just as the caller is being transferred to voicemail. If the caller doesn’t stick around that long you don’t get a notification, however, the fact that you do get a notification doesn’t necessarily mean that the caller actually left a voicemail — if they hang up during the voicemail greeting, a notification would still have already been sent.

EDIT: Here is a different technique for sending notifications on ONLY missed calls, and with this one the notification is sent whether the caller sticks around to leave a voicemail or not. You do NOT add anything to your Follow Me list when using this technique, nor do you modify extensions_custom.conf.

Note that this technique probably will not work on extensions that are part of a Ring Group or Follow Me where more than one extension is rung simultaneously (at least not without some modification — it should work if you use a ring strategy that only rings one phone at a time, though, such as firstnotonphone or firstavailable) (2017 EDIT: Some users have reported those two ring strategies are broken in FreePBX 13 and 14). Be aware that this one is a bit riskier since you will need to re-do the first part of the following procedure after any FreePBX upgrade, otherwise things may break!

  • Load the /etc/asterisk/extensions.conf file into a text editor such as nano
  • Search (Control-W in nano) for the string [from-internal] (including the brackets)
  • Copy the entire context (you can omit the comments) to a new open page in a text editor on your local computer
  • Next, search for the string [from-did-direct] (including the brackets)
  • Also copy that entire context (without the comments) to the same open page in your text editor
  • You MAY also need to copy the context [macro-hangupcall] which is found in /etc/asterisk/extensions_additional.conf. You would do that the same way as the previous two. I don’t show it in the examples below, but further down I’ll explain why you might need to do that one.

At this point the open page in your text editor will look something like this, although this may vary depending on your version of FreePBX. It is important that you copy these contexts from YOUR system, and repeat the procedure every time you upgrade FreePBX to a newer version:

[from-internal] include => from-internal-noxfer
include => from-internal-xfer
include => bad-number ; auto-generated

[from-did-direct] include => ext-findmefollow
include => ext-local

Now add these two lines to the bottom of EACH of the above two contexts (or all three if you also added [macro-hangupcall]):

exten => h,1,Macro(missed-call)
exten => h,n,hangup

The above is the part you will need to redo if you upgrade FreePBX. Next, add a new macro that looks something like this (this is just an example, don’t copy it verbatim!):

[macro-missed-call]
exten => s,1,NoOp(Checking to see if we need to send a missed call notification)
exten => s,n,GotoIf($["${CT_EXTEN}" > "1121" & "${CT_EXTEN}" < "1125" & "${CT_EXTEN}" != "" & "${ANSWEREDTIME}" = ""]?notify1)
exten => s,n,MacroExit()
exten => s,n(notify1),NoOp(Sending notification of missed call on extension ${CT_EXTEN})
exten => s,n,ExecIf($["${CALLERID(num)}" > "1121" & "${CALLERID(num)}" < "1125"]?MacroExit())
exten => s,n,ExecIf($["${CALLERID(num)}" = "8005551212"]?MacroExit())
exten => s,n,JabberSend(asterisk,username@gmail.com,Missed call from ${CALLERID(name)} at ${CALLERID(num)} for extension ${CT_EXTEN} received ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)})
exten => s,n,MacroExit()

Here’s an explanation of what’s happening in the above Macro, so you can modify it for your specific needs:

  • Line 1 is just a NoOp that tells what the macro is doing.
  • Line 2 says that if the call was for extensions 1122 through 1124 (greater than 1121 and less than 1125), that we didn’t get a null value for the extension, and the call was not answered, go to the label notify1. If we only wanted to test for a single extension such as 1122, instead of “${CT_EXTEN}” > “1121” & “${CT_EXTEN}” < “1125” just use “${CT_EXTEN}” = “1122”. You can add as many lines as you need for various extensions, just be sure to jump to different labels.
  • Line 3 says that if none of the above conditions match, exit the macro.
  • Line 4 is just a NoOp that serves as a placeholder for the label and prepares to send the notification.
  • Line 5 is optional and shows how to exclude notifications for calls if the calling number is within a range, in this case 1122-1124 (so, in this example no notifications would be made on calls from one of your own extensions to another in the 1122-1124 range). You can use as many of these lines as you need to exclude more ranges, or none at all if you don’t want to exclude any ranges. Make sure you get the quotation marks right (and again, if you copy lines from this blog, beware of the quotation marks that WordPress has “prettified” – you’ll need to fix them before the lines will work!).
  • Line 6 is optional and shows how to exclude a specific number from triggering the notification. In this case, if the call comes from 8005551212, no notification would be sent. Note that you could use the ${CALLERID(name) variable as a trigger also, and exclude calls from certain names from triggering a notification. Note you can place multiple tests in the same expression by using the bar character (logical OR in Asterisk) to connect them, for example, “${CALLERID(num)}” = “8005551212” | “${CALLERID(name)}” = “INFORMATION” would match if either condition were true. This line can be omitted completely if you don’t want to exclude calls from any specific numbers.
  • Line 7 is where we actually send the notification. Basically any of the methods mentioned in the previous part of this article can be used here, just replace ****1122,1, in the example lines with s,n,
  • Line 8 is where we gracefully exit the macro. Of course, you can repeat lines 4-7 as many times as needed if you are doing notifications for more than one extension.

Now that you have the three (or four) macros in your text file and edited as they should be, copy the whole mess and paste it into the existing file /etc/asterisk/extensions_override_freepbx.conf — do not just overwrite the existing file! Instead, open it with nano or another text editor and paste in the lines you’ve been working on. Also, do a quick scan to make sure you haven’t duplicated a context that’s already in there (the likelihood of that is pretty remote unless you have done something like this in the past). Note that after you do a FreePBX reload, the contexts in this file will replace the equivalents in the files generated by FreePBX, so that’s why you have to check that the originals haven’t changed each time you upgrade FreePBX.

If you want to know what variables are available for you to trigger on, instead of a line sending a notification you can use a line like this:

exten => s,n,DumpChan

This will show you a lot of information, including how several of the channel variables are set.

One final note, the added macro call under [from-internal] is the one that would be taken after a failed call from another extension, while the one under [from-did-direct] is the one used by failed calls coming in from outside the system. Note that most answered calls (not including ones that go to voicemail) will wind up in [macro-hangupcall] and not go through either of those, BUT in certain circumstances unanswered calls might also end via [macro-hangupcall], such as if they go through a ring group. That is why I mentioned above that you might need to include [macro-hangupcall] along with the other contexts copied into /etc/asterisk/extensions_override_freepbx.conf. However, I have not tested every possible condition, and I do know that some things won’t work — such as if multiple extensions are rung simultaneously, no extension number shows up in the ${CT_EXTEN} variable, so those tests in [macro-missed-call] that depend on that variable being set will fail. You may be able to modify the macro so that it will work in such circumstances by using one or more variables you can find by using DumpChan, but that’s a piece of dialplan I’m not prepared to write, since I personally have no need for it (and have already spent way too much time on this)!

I probably should also include this note about the use of extensions_override_freepbx.conf as taken from this page:

If extensions.conf (or extensions_additional.conf) has a context or macro that you NEED to modify, you place that code here as asterisk will only execute the first occurrences of that code and ignores other occurrences. This file will not be overwritten. Be very careful as replacing an existing piece of code this way is the fastest possible way to break your system. If you are doing this you should probably think about filing for a feature request or bug fix to get it addressed properly.

Of course, my experience is that filing a feature request with FreePBX is a great way to either be ignored, or lectured by some a**h*le on why you don’t need that feature, so I wouldn’t bother. Just be sure that if you upgrade FreePBX, or even just the Core or Framework modules, you check to make sure that the contexts you’ve copied into extensions_override_freepbx.conf haven’t been changed (or if they have, make sure you copy over the changes).

How to use the FreePBX [macro-dialout-trunk-predial-hook] macro and regular expressions to blacklist or whitelist outgoing calls on all trunks

 

Important
This is an edited version of a post that originally appeared on a blog called The Michigan Telephone Blog, which was written by a friend before he decided to stop blogging. It is reposted with his permission.

DISCLAIMER: Just because I do something a certain way doesn’t mean YOU should, at least not without extensive testing to make sure that it will do what you want. I do not warrant that anything shown here will in any way save you from getting a high phone bill. If that should happen, consider it a happy coincidence, but if it doesn’t work as you expected, don’t come crying to me. I only offer what I think might work, it’s up to YOU to test it on YOUR system.

This is a followup to my article, Did you know that Asterisk has the ability to evaluate Regular Expressions, though not in the same way as Perl or FreeSWITCH? If you have not read that article, you may want to do that first. Both that article and this one are subject to future revision, if I discover more on this subject.

The problem I have always had on the two systems I help administer is that we don’t allow international calls that cost money. In the past I had resorted to putting a complete list of valid area code patterns in each user’s Outbound Route, and since I had to include patterns for both 11 digit and 10 digit calls, it grew to be a pretty long list. Fortunately, when adding a new user, it was easy to copy the list from an existing user’s outbound account, bring it into a text editor to edit the /extension suffix, and paste it into the new user’s Outbound Route. That worked in FreePBX 2.7, and in versions 2.8 and 2.9 if you use the Swiss Army Knife module, but that module won’t work with FreePBX 2.10 and above.

Unfortunately, as you are very well aware if you have read many of my previous posts, starting in FreePBX 2.8 the FreePBX developers changed the entry method for Outbound Route dial patterns, changing it from an incredibly easy process to enter a list of patterns into a painful, totally stupid method involving individual text boxes for each individual part of each line of each Outbound Route dial pattern. That one change was enough to make me hate FreePBX. The FreePBX developers have been totally unresponsive to those who don’t care for the new method (they pretty much try to pretend such users don’t even exist).

One thing I am NOT going to EVER do is enter a long list of dial patterns using their input method! Someone once said of me that I would spend weeks looking for a way around having to re-type something, when it might only take me a few hours to re-type it, and that’s true. I have even abandoned whole articles because my system crashed and there was no backup, and there was no damn way I was retyping what I had already typed. So in that spirit, I started looking for ways to get around having to enter all those dial patterns for each Outbound Route. I’ve used various stopgap measures including weird things like custom trunks, but that was an ugly solution and leaves extra entries in the Call Detail Records. When I found out that Asterisk could use Regular Expressions, I figured out this method, which is actually much faster, and gives me another way to bypass the limitations of FreePBX.

This uses the [macro-dialout-trunk-predial-hook] macro which is already present, but commented out, in /etc/asterisk/extensions_custom.conf. The thing you need to understand about this macro is that it is called AFTER most of the dial plan associated with both the outbound route and the trunk have been applied. So if you change the called number in either the Outbound Route Dial Patterns or the Trunk Dialed Number Manipulation Rules, those transformations will already have been applied by the time this macro is called. Also, if the calling number has been changed (by setting the Outbound Caller ID in the Trunk, for example), that change have been made by the time this macro is called. And finally, this macro is called when a call is about to go out on ANY trunk in your system (at least I think it does, although I haven’t tested it with every possible trunk type. I’m reasonably sure it is called whenever a call is destined for a SIP trunk, but I am not sure that it gets called if you use one of the other available types of trunks. It does NOT seem to get called when a call is destined for an ENUM trunk). If you don’t want it to act on calls from a certain trunk, you need to test for that and bail out of the macro (I show an example of that below).

The interesting thing about this is that because this macro is invoked so late in the progress of an outgoing call, you can use it as a last chance to look for “undesirable things” or to send notifications of certain happenings. For example, although I don’t show exactly how to do it below, you could have it send an instant message or an e-mail notification when someone calls a specific number, such as 911.

What I am showing here is what I have set up on one of my systems. This assumes that the outbound routes only contain the following Dial Patterns (not all Outbound Routes will contain all of these, and I assume that each user has their own outbound route, or that groups of users may share outbound routes):

1NXXNXXXXXX/ext
NXXNXXXXXX/ext
1aaa+NXXXXXX/ext

…where aaa is the user’s local area code for 7 digit dialing , and ext is the user’s extension (which could be a pattern to allow a group of extensions). In addition, if the user’s service allows the *67 code to be used to block outgoing Caller ID, then these patterns might also be used (with the same substitutions):

*671NXXNXXXXXX/ext
*67NXXNXXXXXX/ext
*671aaa+*67|NXXXXXX/ext

The way I have set it up also ignores any number under 10 digits (allowing it to go through) so if you have dial patterns that allow users to dial provider service codes, or extensions on another connected server, or some such thing, those calls won’t be affected — only calls of 10 digits or longer are checked (this is one reason I prepend the area code to 7 digit calls in the Outbound Routes). Note that there are long lines in the following so if you want to see them in their entirety, you need to cut and paste this into a text editor:

[macro-dialout-trunk-predial-hook]
; this macro intentially left blank so it may be safely overwritten for any custom
; requirements that an installation may have.
;
; MACRO RETURN CODE: ${PREDIAL_HOOK_RET}
;                    if set to "BYPASS" then this trunk will be skipped
;
exten => s,1,NoOp(Trunk ${OUT_${DIAL_TRUNK}} selected)
exten => s,n,ExecIf($[${LEN(${OUTNUM})}<10]?MacroExit())
exten => s,n,ExecIf($["${OUT_${DIAL_TRUNK}}"="SIP/TollFree-Future9"]?MacroExit())
exten => s,n,Set(regx=^([*]67)?1?900[0-9]{7}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?premium)
exten => s,n,Set(regx=^([*]67)?1?8(00|22|33|44|55|66|77|88)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?tollfree)
exten => s,n,Set(regx=^([*]67)?1?[2-9][0-9]{2}976[0-9]{4}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?premium)
exten => s,n,Set(regx=^([*]67)?1?(201|202|203|205|206|207|208|209|210|212|213|214|215|216|217|218|219|220|223|224|225|228|229|231|234|239|240|248|251|252|253|254|256|260|262|267|269|270|272|274|276|279|281|301|302|303|304|305|307|308|309|310|312|313|314|315|316|317|318|319|320|321|323|325|327|330|331|332|334|336|337|339|346|347|351|352|360|361|364|380|385|386|401|402|404|405|406|407|408|409|410|412|413|414|415|417|419|423|424|425|430|432|434|435|440|442|443|445|458|463|469|470|475|478|479|480|484|501|502|503|504|505|507|508|509|510|512|513|515|516|517|518|520|530|534|539|540|541|551|559|561|562|563|564|567|570|571|573|574|575|580|585|586|601|602|603|605|606|607|608|609|610|612|614|615|616|617|618|619|620|623|626|628|629|630|631|636|641|646|650|651|657|660|661|662|667|669|678|680|681|682|701|702|703|704|706|707|708|712|713|714|715|716|717|718|719|720|724|725|726|727|731|732|734|737|740|743|747|754|757|760|762|763|765|769|770|772|773|774|775|779|781|785|786|801|802|803|804|805|806|808|810|812|813|814|815|816|817|818|828|830|831|832|838|843|845|847|848|850|854|856|857|858|859|860|862|863|864|865|870|872|878|901|903|904|906|907|908|909|910|912|913|914|915|916|917|918|919|920|925|928|929|930|931|934|936|937|938|940|941|947|949|951|952|954|956|959|970|971|972|973|978|979|980|984|985|986|989)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?usa)
exten => s,n,Set(regx=^([*]67)?1?(204|226|236|249|250|289|306|343|365|367|403|416|418|431|437|438|450|506|514|519|548|579|581|587|604|613|639|647|705|709|778|780|782|807|819|825|867|873|879|902|905)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?canada)
exten => s,n,Set(regx=^0118835100[0-9]{8}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?inum)
exten => s,n,NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a NOT a permitted call)
exten => s,n,Jabbersend(asterisk,system_administrator_address@gmail.com,${CALLERID(num)} attempted to call ${OUTNUM} at ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)})
exten => s,n,Playback(custom/sorry-outside-us-canada)
exten => s,n,Macro(hangupcall,)
exten => s,n,Set(PREDIAL_HOOK_RET=BYPASS)
exten => s,n,MacroExit()
exten => s,n(premium),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a premium number call - NOT perrmitted)
exten => s,n,Jabbersend(asterisk,system_administrator_address@gmail.com,${CALLERID(num)} attempted to call a premium number ${OUTNUM} at ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)})
exten => s,n,Playback(silence/1&sorry-cant-let-you-do-that3)
exten => s,n,Macro(hangupcall,)
exten => s,n,Set(PREDIAL_HOOK_RET=BYPASS)
exten => s,n,MacroExit()
exten => s,n(usa),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a USA call)
exten => s,n,MacroExit()
exten => s,n(canada),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a Canada call)
exten => s,n,MacroExit()
exten => s,n(tollfree),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a toll free call)
exten => s,n,MacroExit()
exten => s,n(inum),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is an inum call)
exten => s,n,MacroExit()
exten => h,1,Macro(hangupcall,)

Now here’s a breakdown of the above, in which I try to explain what I have done. I will note at the outset that some may think I am using two lines where one will do, by putting the regular expression into a variable when I could just evaluate it directly in the REGEX function in the following line. However, when I was researching the use of regular expressions in Asterisk, I read on several pages that at least some versions of Asterisk have issues parsing a regular expression if it contains certain characters that also have a meaning to Asterisk, unless you put the regex into a string variable first and then use that in the REGEX function. I don’t know if that’s always true but I figured better safe than sorry, and besides, it’s much less confusing to me when I do it that way. But if you want to try combining the two-line pairs into one, feel free — it’s your system, and your headache if it doesn’t work. Also, remember that Asterisk doesn’t parse regular expressions in the same way that some other software (such as Perl) does, so if you try to simplify my regex patterns you might run into trouble. So with that said, let’s begin our tour.

This part of the macro is already present in extensions_custom.conf. You only need to uncomment the lines that are not obviously comments:

[macro-dialout-trunk-predial-hook]
; this macro intentially left blank so it may be safely overwritten for any custom
; requirements that an installation may have.
;
; MACRO RETURN CODE: ${PREDIAL_HOOK_RET}
;                    if set to "BYPASS" then this trunk will be skipped
;
exten => s,1,NoOp(Trunk ${OUT_${DIAL_TRUNK}} selected)

The next line is the first of many places we will use MacroExit() to bail out of the macro. This checks to see in the number called was 9 digits or less. We don’t want to block 911 calls, intra-company calls to other extensions, calls to another network that uses extensions of 9 digits or less, etc.:

exten => s,n,ExecIf($[${LEN(${OUTNUM})}<10]?MacroExit())

This bails out if the call is going out a specific trunk. In this case we don’t want to mess with toll-free calls going to Future9 because they are sent using a rather unusual pattern that would not be recognized by the regular expressions below.

exten => s,n,ExecIf($["${OUT_${DIAL_TRUNK}}"="SIP/TollFree-Future9"]?MacroExit())

Here’s an example of blocking a call that conforms to a specific pattern, in this case 1-900-XXX-XXXX or just 900-XXX-XXXX. It will block calls with or without the *67 (privacy) prefix, and with or without the leading “1”. If you don’t allow *67 calling then just remove the [*]67)? from the start of the expression. If it matches that pattern, it is transferred to the label “premium”, which we’ll get to in a bit:

exten => s,n,Set(regx=^([*]67)?1?900[0-9]{7}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?premium)

Here’s an example of allowing a call that matches a specific pattern, in this case a NANP toll-free call, again with or without the *67 (privacy) prefix (as is the case with most of these regular expressions — note that your outbound route(s) would also need to allow the *67 pattern). These calls are transferred to the label “tollfree”, which we’ll also talk about later:

exten => s,n,Set(regx=^([*]67)?1?8(00|22|33|44|55|66|77|88)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?tollfree)

Here we block calls that match the pattern 1-[2-9]XX-976-XXXX or just [2-9]XX-976-XXXX (with or without a *67 prepend) and send them to “premium”:

exten => s,n,Set(regx=^([*]67)?1?[2-9][0-9]{2}976[0-9]{4}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?premium)

Here we test to see if the call is going to any USA area code. This is a really long regex but it works. If the pattern matches, it transfers to the “usa” label

exten => s,n,Set(regx=^([*]67)?1?(201|202|203|205|206|207|208|209|210|212|213|214|215|216|217|218|219|220|223|224|225|228|229|231|234|239|240|248|251|252|253|254|256|260|262|267|269|270|272|274|276|279|281|301|302|303|304|305|307|308|309|310|312|313|314|315|316|317|318|319|320|321|323|325|327|330|331|332|334|336|337|339|346|347|351|352|360|361|364|380|385|386|401|402|404|405|406|407|408|409|410|412|413|414|415|417|419|423|424|425|430|432|434|435|440|442|443|445|458|463|469|470|475|478|479|480|484|501|502|503|504|505|507|508|509|510|512|513|515|516|517|518|520|530|534|539|540|541|551|559|561|562|563|564|567|570|571|573|574|575|580|585|586|601|602|603|605|606|607|608|609|610|612|614|615|616|617|618|619|620|623|626|628|629|630|631|636|641|646|650|651|657|660|661|662|667|669|678|680|681|682|701|702|703|704|706|707|708|712|713|714|715|716|717|718|719|720|724|725|726|727|731|732|734|737|740|743|747|754|757|760|762|763|765|769|770|772|773|774|775|779|781|785|786|801|802|803|804|805|806|808|810|812|813|814|815|816|817|818|828|830|831|832|838|843|845|847|848|850|854|856|857|858|859|860|862|863|864|865|870|872|878|901|903|904|906|907|908|909|910|912|913|914|915|916|917|918|919|920|925|928|929|930|931|934|936|937|938|940|941|947|949|951|952|954|956|959|970|971|972|973|978|979|980|984|985|986|989)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?usa)

Same as the previous except now we’re testing for Canadian area codes, and if successful transferring to the “canada” label:

exten => s,n,Set(regx=^([*]67)?1?(204|226|236|249|250|289|306|343|365|367|403|416|418|431|437|438|450|506|514|519|548|579|581|587|604|613|639|647|705|709|778|780|782|807|819|825|867|873|879|902|905)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?canada)

(NOTE: It should be noted that a few new area codes are added every year. You can see a list of the most recently added ones here: NPAs Introduced over the Last 10 Years. You should check this periodically and add the new USA and Canadian area codes to the appropriate sections above.)

Google Voice used to complete calls to iNum numbers for free, so this test allowed for those. Now I don’t use this section, but leave it here as an example. Back when these calls were free, this was the only “international” format call that was permitted on our system:

exten => s,n,Set(regx=^0118835100[0-9]{8}$)
exten => s,n,GotoIf($[${REGEX("${regx}" ${OUTNUM})} = 1]?inum)

If we get here, the call failed all the tests that would indicate it might be a permitted call. I play a custom recorded message that tells the caller that their call is not allowed, possibly because it’s not to a destination in the United States or Canada. Just prior to playing the message, I use the Jabbersend function to send myself an instant message showing that a call failed. I mainly do this so I can determine whether the caller really tried to dial a number that’s not permitted, or if there’s an error in my logic. For example, someone could be trying to place calls to a valid area code that somehow got omitted from the regular expression. Note that Jabbersend will only work if you have jabber.conf configured correctly AND the res_jabber.so module is loading when Asterisk starts up. If you have ever configured your server to place Google Voice calls using Asterisk’s jabber/gtalk support, those things are probably true, but it still may be a bit tricky to get working, however I’m not going to discuss that in this article — just search for Asterisk Jabbersend in a search engine if you need help:

exten => s,n,NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a NOT a permitted call)
exten => s,n,Jabbersend(asterisk,system_administrator_address@gmail.com,${CALLERID(num)} attempted to call ${OUTNUM} at ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)})
exten => s,n,Playback(custom/sorry-outside-us-canada)
exten => s,n,Macro(hangupcall,)
exten => s,n,Set(PREDIAL_HOOK_RET=BYPASS)
exten => s,n,MacroExit()

One further note about the last three lines in the above section: Setting the PREDIAL_HOOK_RET variable and the MacroExit() are probably superfluous because the Macro(hangupcall,) will terminate the call, but I left them there for safety. Note that if you were to comment out the Macro(hangupcall,), the last two lines would execute, and then if more than one trunk was specified in the Outbound Route, it would keep retrying the call on each of those trunks (and the caller would hear the error message multiple times, and you’d get multiple IM’s). Although I can’t personally envision such a situation, there might be situations where trying the additional trunks would be desirable.

Next is where the call goes if the caller attempted to dial a premium (900 or 976) number. This is similar to the previous section, except the recording played to the caller is one second of silence followed by a standard system recording. The silence is necessary to keep the first word or two of the recording from being cut off on some clients. Also the IM I send to myself is slightly different. And the same comment applies on the last three lines. I know, I could have done a Goto to the same three lines in the previous section, but that would have only saved me two lines, and since the last two lines are superfluous anyway, if you are that tight on space you can just delete them.

exten => s,n(premium),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a premium number call - NOT perrmitted)
exten => s,n,Jabbersend(asterisk,system_administrator_address@gmail.com,${CALLERID(num)} attempted to call a premium number ${OUTNUM} at ${STRFTIME(${EPOCH},,%l:%M:%S %p %Z on %A %B %e)})
exten => s,n,Playback(silence/1&sorry-cant-let-you-do-that3)
exten => s,n,Macro(hangupcall,)
exten => s,n,Set(PREDIAL_HOOK_RET=BYPASS)
exten => s,n,MacroExit()

The next sections contain the usa, canada, tollfree, and inum labels. All they do is print an appropriate message to the CLI and exit. Rather than jump to these labels, I could have simply used statements of the form ExecIf($[${REGEX(“${regx}” ${OUTNUM})} = 1]?MacroExit()) and left out this entire next section, but I like the idea of being able to see which regex allowed the call in the CLI, and this also allows for the possibility of additional code. For example, I could insert code that keeps a running tally of calls broken down by their destination. I have no need to do anything like that, but maybe you do:

exten => s,n(usa),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a USA call)
exten => s,n,MacroExit()
exten => s,n(canada),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a Canada call)
exten => s,n,MacroExit()
exten => s,n(tollfree),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a toll free call)
exten => s,n,MacroExit()
exten => s,n(inum),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is an inum call)
exten => s,n,MacroExit()

This last line is important and was omitted from the default macro. It handles the case where the caller hangs up while this code is executing. Although that window is only a small fraction of second, bad things could happen if the caller does manage to hang up within that window and this statement isn’t present:

exten => h,1,Macro(hangupcall,)

Well, that’s how I’m doing it right now. It may not be how I do it two months from now, but this seems better than any method I have used thus far.

I will point out, for whatever it’s worth, that you COULD use an Asterisk dial command right in this macro. So, for example, let’s say you had a trunk that was real expensive at a certain time of the day but much cheaper during another. You COULD test to see if the call is being made within the “cheap” time and if so just exit, but if not you could execute a dial command that looks like the one normally executed, which is…

exten => s,n,Dial(${OUT_${DIAL_TRUNK}}/${OUTNUM},300,${DIAL_TRUNK_OPTIONS})

…except that in place of ${OUT_${DIAL_TRUNK}} you could specify a different trunk, for example SIP/OtherTrunk. And of course you could use this macro to change the dial trunk options for specific trunks, or to play a recording to callers if their call is going out over an “expensive” trunk. In fact, I can see where this macro could be used to get to get around some of the FreePBX syntax checking that has plagued me in the past.

It should probably be noted that if you watch these macros execute in the Asterisk CLI, every time one of them is executed you may see a WARNING message such as this:

[2012-11-22 11:48:12] WARNING[30588][C-00000055]: pbx.c:1585 pbx_exec: The application delimiter is now the comma, not the pipe. Did you forget to convert your dialplan? (Set(regx=^([\*]{2}1)?([\*]67)?W?1?8(00|22|33|44|55|66|77|88)[2-9][0-9]{6}$))

This warning doesn’t apply in this situation because the pipe IS the correct character to use in a regular expression, when you are matching a single regular expression out of several possible regular expressions. See this page on Alternation with The Vertical Bar or Pipe Symbol for more information, with the caveat that Asterisk’s expression engine is a bit different from that used in other software, and therefore may not recognize syntax that would be perfectly valid in another application. Therefore, not all examples shown on various regular expression tutorials or reference pages will work. If you wish to try a particular syntax, be sure to do a test run or two and make sure it works. But, Asterisk’s regular expression engine DOES recognize the pipe character when used as shown in the above examples, but spits out these warning messages anyway, even though the pipe characters are part of the regular expression, and are not being used as application delimiters. You can safely ignore the warnings – they are a nuisance, but are meaningless in this particular situation. If you really don’t want to see those warnings, use a text editor to go to /etc/asterisk/asterisk.conf and uncomment this line:

;dontwarn = yes                 ; Disable some warnings.

This will disable some non-essential warnings such as this one. If it were me, I would have named this option “stopwhining” rather than “dontwarn”, because Asterisk does tend to complain a lot about things that don’t matter and that you can’t do anything about. 🙂

Once again, I will mention that articles in this blog (and especially one such as this) are subject to future editing as I discover more about the subject. If you find any neat uses for the [macro-dialout-trunk-predial-hook] macro (ESPECIALLY if they allow you to do something that FreePBX tries to stop you from doing, but that’s perfectly allowable in Asterisk), feel free to leave a comment!

Did you know that Asterisk has the ability to evaluate Regular Expressions, though not in the same way as Perl or FreeSWITCH?

 

Important
This is an edited version of a post that originally appeared on a blog called The Michigan Telephone Blog, which was written by a friend before he decided to stop blogging. It is reposted with his permission. Comments dated before the year 2013 were originally posted to his blog.

I happened to be searching the Asterisk issue tracker a few minutes ago (trying to figure out why the Asterisk Blacklist suddenly stopped working for no apparent reason on one of my systems) and happened to notice this issue which had just been posted today:

REGEX function ignores shorthand character starting with backslash

Wait, you mean Asterisk can evaluate Regular Expressions? I didn’t think it had that capability. So, working off the example shown in that issue report (the working expression, naturally) I tried putting this in the FreePBX extensions_custom.conf [macro-dialout-trunk-predial-hook] context (I had to uncomment some existing lines and add others). This is just example code and not meant to do anything useful. NOTE: Many of the lines in code blocks below won’t fit on the screen due to the way WordPress formats this blog, but if you copy and paste the lines into a text editor you should see them in their entirety:

[macro-dialout-trunk-predial-hook]
; this macro intentially left blank so it may be safely overwritten for any custom
; requirements that an installation may have.
;
; MACRO RETURN CODE: ${PREDIAL_HOOK_RET}
;                    if set to "BYPASS" then this trunk will be skipped
;
exten => s,1,NoOp(Trunk ${OUT_${DIAL_TRUNK}} selected)
exten => s,n,Set(tftest=^1?8(00|22|33|44|55|66|77|88)[2-9][0-9]{6}$)
exten => s,n,GotoIf($[${REGEX("${tftest}" ${OUTNUM})} = 1]?tollfree)
exten => s,n,NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a NOT a toll free call)
exten => s,n,MacroExit()
exten => s,n(tollfree),NoOp(${CALLERID(num)} is calling ${OUTNUM} which is a toll free call)
exten => s,n,MacroExit()

If you place an outgoing call and watch the Asterisk CLI, you will see that if you place a call it knows what trunk was selected and what number the call came from, and prints that it is or is not a toll-free call. And I assume you could get other information about the call from other system variables. This could be handy for extended call routing, or for blocking of certain calls.

The thing to note here is that the dialplan only uses only one line to test for all the possible NANP toll-free area codes, both with and without a “1” prefix — you could do this without using a regular expression, but you’d need one line per area code to test. If you’ve ever looked at the FreePBX generated dialplan (in extensions_additional.conf) you know that much of the dialplan is lines upon lines of pattern specifications. I’ve mentioned in the past the problem of specifying every USA or Canadian area code in an outbound routes (so you can disallow calls to NANP points not covered by your calling plan) but it occurs to me that if FreePBX utilized regular expressions, it MIGHT be possible to condense many lines into one. Of course this would partly depend on whether there is a length limit on a regular expression, but in later testing I tried setting REGEX variables for the USA and Canada, like this:

This line that would create a regex that would test for USA calls (50 states + D.C.):

exten => s,n,Set(usatest=^1?(201|202|203|205|206|207|208|209|210|212|213|214|215|216|217|218|219|220|223|224|225|228|229|231|234|239|240|248|251|252|253|254|256|260|262|267|269|270|272|274|276|279|281|301|302|303|304|305|307|308|309|310|312|313|314|315|316|317|318|319|320|321|323|325|327|330|331|332|334|336|337|339|346|347|351|352|360|361|364|380|385|386|401|402|404|405|406|407|408|409|410|412|413|414|415|417|419|423|424|425|430|432|434|435|440|442|443|445|458|463|469|470|475|478|479|480|484|501|502|503|504|505|507|508|509|510|512|513|515|516|517|518|520|530|534|539|540|541|551|559|561|562|563|564|567|570|571|573|574|575|580|585|586|601|602|603|605|606|607|608|609|610|612|614|615|616|617|618|619|620|623|626|628|629|630|631|636|641|646|650|651|657|660|661|662|667|669|678|680|681|682|701|702|703|704|706|707|708|712|713|714|715|716|717|718|719|720|724|725|726|727|731|732|734|737|740|743|747|754|757|760|762|763|765|769|770|772|773|774|775|779|781|785|786|801|802|803|804|805|806|808|810|812|813|814|815|816|817|818|828|830|831|832|838|843|845|847|848|850|854|856|857|858|859|860|862|863|864|865|870|872|878|901|903|904|906|907|908|909|910|912|913|914|915|916|917|918|919|920|925|928|929|930|931|934|936|937|938|940|941|947|949|951|952|954|956|959|970|971|972|973|978|979|980|984|985|986|989)[2-9][0-9]{6}$)

Yes, that is all one single line (which you won’t see in its entirety if you don’t copy and paste the part you do see into a text editor, but it’s humongous)! But it seems to work if you use the ${usatest} variable instead of ${tftest} in the line containing the REGEX function! And here’s one for Canada that puts the expression into ${cdntest}:

exten => s,n,Set(cdntest=^1?(204|226|236|249|250|289|306|343|365|367|403|416|418|431|437|438|450|506|514|519|548|579|581|587|604|613|639|647|705|709|778|780|782|807|819|825|867|873|879|902|905)[2-9][0-9]{6}$)

Of course you could test for all three types of calls in the same block of code. Just remember that the code as shown above is handling calls destined for ALL your trunks, so if you only want it to operate on a single trunk you’ll have to test for that trunk only, and bail out if the call is headed for any other trunk.

For the moment all I will say is that this opens up interesting possibilities, including possibly new ways to get around some of the developer-imposed limitations of FreePBX, and also to streamline custom dialplan. Unfortunately it appears that Asterisk’s REGEX function support is not much used nor well documented, so you may have trouble finding other examples of working code that uses this function.

Also, Matt Jordan commented on the issue linked above, noting that “REGCOMP is built on the GNU extended regular expressions library (see regex.h). That library does not support the shorthand characters (see this comparison of regular expression libraries). As such, this is not a bug, but a limitation of the library that provides the regular expression functionality.” What this apparently means is that you cannot use something like d or [:digit:] to represent any digit, as you can do in other software that recognizes regular expressions, but [0-9] works just fine for that purpose. However, it would not be correct to say that backslashes can never be used, as I found these uses of REGEX in extensions_additional.conf:

exten => s-fixed,1,ExecIf($["${REGEX("^[+]?[0-9]+$" ${DB(RINGGROUP/${NODEST}/fixedcid)})}" = "1"]?Set(__TRUNKCIDOVERRIDE=${DB(RINGGROUP/${NODEST}/fixedcid)}))
exten => s-fixed,n,Return()
exten => s-extern,1,ExecIf($["${REGEX("^[+]?[0-9]+$" ${DB(RINGGROUP/${NODEST}/fixedcid)})}" == "1" & "${FROM_DID}" != ""]?Set(__TRUNKCIDOVERRIDE=${DB(RINGGROUP/${NODEST}/fixedcid)}))
exten => s-extern,n,Return()
exten => s-did,1,ExecIf($["${REGEX("^[+]?[0-9]+$" ${FROM_DID})}" = "1"]?Set(__REALCALLERIDNUM=${FROM_DID}))
exten => s-did,n,Return()
exten => s-forcedid,1,ExecIf($["${REGEX("^[+]?[0-9]+$" ${FROM_DID})}" = "1"]?Set(__TRUNKCIDOVERRIDE=${FROM_DID}))
exten => s-forcedid,n,Return()

Note the use of [+] in the REGEX expressions above. That “escapes” the + character, which otherwise would have a meaning in a regular expression, but for some reason the escaped character has to be enclosed in square brackets.  This can lead to some non-obvious regex constructions.  For example, look again at the line that creates a regex that would test for USA calls.  It begins like this:

exten => s,n,Set(usatest=^1?(201...

The question mark after the “1” means it’s optional. But what if the provider also accepts calls prefixed with *67 to block the Caller ID? You could allow for that possibility like this in most software that accepts regular expressions, but not in Asterisk…

exten => s,n,Set(usatest=^(*67)?1?(201...

The backslash would escape the * character, and therefore the string *67 would be considered optional. But in Asterisk, you have to enclose the * in square brackets to make this work, like so:

exten => s,n,Set(usatest=^([*]67)?1?(201...

Anyway, I just wanted to bring this to your attention, in case that you (like me) were thinking that Asterisk doesn’t interpret regular expressions. It DOES, but not in the same manner as Perl, nor FreeSWITCH for that matter. If anyone knows of an online reference or “cheat sheet” for this particular variety of regular expression library, I’d appreciate the link.

Link: How to do Painless MySQL Server Backups with AutoMySQLBackup

 

Important
This is an edited version of a post that originally appeared on a blog called The Michigan Telephone Blog, which was written by a friend before he decided to stop blogging. It is reposted with his permission. Comments dated before the year 2013 were originally posted to his blog.

Image representing MySQL as depicted in CrunchBase

I have not tried or tested this, but just wanted to point it out as it might prove useful to some readers. I still prefer MondoRescue for a full system backup, but I can see how this might also come in handy in certain situations:

How to do Painless MySQL Server Backups with AutoMySQLBackup (Linux.com)

Featured Article:

Recent Posts

Recent Comments

Archives

Categories

Meta

GiottoPress by Enrique Chavez

%d bloggers like this: