Interesting thread on integrating Speech to Text with Asterisk and PBX in a Flash

 

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.
An old microphone
Image via Wikipedia

I just wanted to call your attention to this thread on the PBX in a Flash forum:

Exploring Speech to Text

This thread explores the possibility of adding a simple speech to text demo, and also discusses the possibility of transcribing e-mails to text.  It uses Google’s speech recognition service, and it is free to use.  I doubt you would be free to use it in any commercial application, but for those that just like to tinker with new capabilities for your Asterisk server, you might find this interesting.

I haven’t personally tried it yet, but I will say that if you are using some FreePBX based distro other than PBX in a Flash, you may need to remove the calls to the Flite speech synthesizer (or install Flite support).  I hate Flite (I think the voice quality sucks harder than a black hole — okay, maybe I exaggerate a little, but Cepstral voice synthesis is much better than Flite — unfortunately Cepstral is not free) so I’m not going to tell you how to install it.  Flite’s only used in the demo in the first post so if you are trying to do something else (such as attempt voicemail transcription, as discussed in the thread) you probably don’t need it anyway.

What would be nice would be the ability to dial a code, record a short message, and then have a transcription e-mailed to the address you use for voicemail notifications.  THAT is something I’d actually use on occasion!

EDIT: After posting this, I tried a basic installation on a NON-PBX in a Flash system.  Besides removing the references to Flite, I found I had to do the following:

  1. Change ownership of /var/lib/asterisk/agi-bin/speech-recog.agi to  asterisk:asterisk
  2. Install the perl modules mentioned in the “use” statements in /var/lib/asterisk/agi-bin/speech-recog.agi
  3. Install flac (some users may also need to install sox, but I had installed that previously).

Create an “Unmount” service in Mac OS X

 

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 have been having a problem with a couple of different USB devices that I occasionally connect to my Mac.  I would attempt to eject them and they would immediately remount themselves.  Therefore, it was almost impossible to do a “clean” disconnect of the device.  If you’ve had this problem you’ll know exactly what I’m talking about, and if you haven’t then you don’t need this article.  If you choose to use the information here, bear in mind that even though it worked for me I have no idea what it will do on your system, so use at your own risk or don’t use it at all!

I found that I could “Unmount” rather than “Eject” the devices using Disk Utility and then they would not automatically remount, but it was a bit of a pain to have to go to Disk Utility every time I wanted to unmount a device.  Automator to the rescue! Here are the three steps to create and use an “Unmount” service in OS X:

1. Fire up the Automator application and when it comes up, tell it you want to create a Service:

2. Create an Automator workflow exactly as shown here (click on the image to enlarge it).  Note that the top part must say “Service receives selected Folders in Finder” and after that there is one step, “Run Shell Script”, in which you’ll pass input as arguments. In the text field simply put hdiutil unmount $1

Save the workflow using an appropriate filename (I suggest “Unmount”). It will be saved in your ~/Library/Services/ directory.

3. To use the service, open your /Volumes directory in Finder and select the volume you want to unmount, and right-click on it (or however you bring up the context menu in Finder on your system). Near the bottom you should see a menu selection for “Services” and in a sub-menu you should find your “Unmount” service:

Click on that and your volume should be unmounted (if you have Hardware Growler installed from any version of Growl, including the free forked Lion version, then you should get a Growl notification of the unmount). I will note that this has no error checking other than that built into the command-line hdiutil program, so while it probably won’t hurt anything if you try to unmount something that’s not unmountable (such as a file), I’d still try to be careful.

If you have a problem with devices that refuse to unmount the then you could use the same procedure to create a “Force Unmount” service. I’d still create the regular “Unmount” service as shown above, but if you sometimes have the problem that the device won’t unmount the normal way then simply follow the above steps again except name the service “Force Unmount” and add the -force flag, like this:

hdiutil unmount -force $1

Or if eject normally works, but sometimes you want to force it, you could create a “Force Elect” service using:

hdiutil eject -force $1

I do not guarantee anything with regard to the use of the -force option (I read about it here), so if you go that route and lose data, don’t blame me.  As I said, you use this stuff at your own risk.

Happy unmounting!  And if this doesn’t work for you the way it worked for me, I’ll tell you up front that I have no clue why, and that’s partly because I don’t understand why a plain old eject attempt fails on some systems (as I say, eject actually does work, but then the device immediately remounts).  It’s all a mystery to me!

Links: OS X Notifier App Growl Goes Closed Source, but a free forked version (that works in Lion) is available

 

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.

Here’s a few links on this issue:

OS X Notifier App Growl Goes Closed Source (Slashdot)

Episode 47 – Fork You Growl! Interview with Perry Metzger (from The Basement Coders Developer Podcast — if you care at all about Growl you should listen to this, preferably before spending any money on their allegedly broken App).

[growl-discuss] Growl 1.2.x for Lion source for XCode 4.1 (including a fixed HardwareGrowler)

Patched version project page on bitbucket

Download page for forked version

Growl-1.2.2f1.dmg direct download link (if it doesn’t work check the link above — there may be a newer version).

EDIT: Link to Growl Source Installation information for Growl 1.3 — it appears that after the Slashdot article was published, the Growl developers decided to release the source to Growl 1.3 (making the headline of the Slashdot article and this article inaccurate in the process).  However, this does not mean that the problems with the new version have been fixed (as of the date of this article) — it probably only means that they didn’t like the bad publicity about not releasing the source and decided to address that issue, in an attempt to blunt some of the criticism.

I’m presenting the above links so that anyone interested can check them out (and so I can find them again in the future). I will just say that I generally agree with the sentiments expressed in the podcast. I think it’s really underhanded when a project that has been free for years (and has accepted contributions of both cash and code from folks that probably thought it would be free forever) tries to go commercial, and it’s even worse when the commercial app doesn’t work as well as the previous free version.  And I won’t even get into the issue of the censorship, because the Growl developers have the right to censor whomever they want in their forums, but in this case it sure sounds like they were trying to deprive their users of the knowledge that someone else had fixed their buggy code and made it freely available.  If they choose to do that, then it’s up to others (like you and I) to let Growl users know that an alternative exists.

I hope that either the forked version gains acceptance (and exposure, since few people seem to know about it at the moment) or the original Growl developers see the error of their ways sooner rather than later. What IS it with developers turning greedy lately?  Keep in mind that had Growl not existed (and worked so well in its previous free incarnation), it’s quite likely that the Apple folks would have developed their own notification system and made it a component of OS X.

EDIT:  Two things you should know about Growl 1.3 before you fork over your two bucks:  First, due to App Store requirements, it no longer installs as a preference pane in System Preferences – it’s now an application (the podcast explains this in more detail).  And second, “Growl 1.3 and later do not have update checkers built into them, so you will need to keep up with when releases are put out”, according to the Growl Source Installation page.

Full disclosure:  I also censor comments — see my comment policy in the right sidebar — but it’s generally because they are spam or include one or more links that I consider spam, or because someone is being rude and nasty.  You can call me all the names you like, but I’m not going to approve such garbage for others to read.  However, there are right reasons and wrong reasons to censor comments or to ban a user, and I’ll leave it to the reader to decide (after listening to the linked podcast, which I strongly recommend before you form any strong opinions on this) whether the Growl folks should have banned Mr. Metzger.

Link and comment: Slate Reprints Blue-Box Article That Inspired Jobs

 

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.
Blue Box at the Computer History Museum
Image via Wikipedia
From a post on Slashdot, posted by timothy on Monday October 10, @05:09AM:

Slate has reprinted the piece that Ron Rosenbaum wrote for Esquire in 1971, explaining to the world that there was an underground movement of people hacking the phone system. (Rosenbaum is now a columnist for Slate.) According to the article’s new introduction and followup piece by Rosenbaum reflecting on its impact — and to the New York Times obituary for Steve Jobs — this article inspired Jobs and Wozniak to start building blue boxes themselves, an effort that made them several thousand dollars.

It has been reported (though I can’t recall the source at the moment) that this is the article that caused AT&T to turn its employees into common thieves.  The idea that people might have access to this information frightened them so much that they literally sent their people out to steal the copies of this issue of Esquire from every public library in the country (of course they missed a few).  Although this was long before the days of the Internet and the “Streisand effect“, it did have the result that those who had access to the article had a tendency to photocopy it and pass it around, so AT&T’s ham-fisted attempt at censorship probably gave the article far more exposure than it ever would have had in the first place.

I would daresay that one article probably had a significant effect on our modern way of life.  For one thing, it taught us that “security through obscurity” doesn’t work, and for another it forced AT&T and other phone companies to modernize their phone networks (probably much earlier than they would have otherwise intended) to prevent the type of “toll fraud” made possible by the blue box, and that made it much easier for alternative long distance carriers to offer their services.

Although I never had the technical skills to build a blue box, I definitely wanted to know how they worked.  The copy of Esquire at my local library had already gone missing but I discovered they still had a copy at the Grand Rapids public library.  Apparently the librarians there had apparently been tipped off about AT&T’s attempts to make that issue disappear, so they were keeping it behind the desk and you had to request it from a librarian.  Which I did, and then promptly asked where the photocopy machine was.  The librarian looked me over and said, “You’re not going to copy that article, are you?” and I said, “Oh, yes I am!”  She clearly disapproved, but still pointed me in the direction of the copier (the alternative would have been to attempt to forcibly pry the magazine back out of my hands!).  That copy of the article went back home with me and got shared with a few interested friends, and at least two of them later got jobs in the telecommunications field.

Of course, nowadays it would be a simple task for any modern computer to generate the same multifrequency tomes that blue boxes generated, but the last telephone company in the country to actually use that signaling method dropped it on June 15, 2006.  And now we have computers and the Internet and VoIP, but I have a feeling that much of that might still not be in existence had it not been for that one article, which literally gave birth to an entire community of hackers, many of whom later went on to do great things and to build the networks we have today.  It’s funny how one thing that seems so small at the time — in this case, one magazine article — can create such ripples throughout society.

How to install the BIND DNS Server using Webmin, so Asterisk extensions (hopefully) will work even when your Internet connection fails

 

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.

If you run Asterisk you may have encountered this issue: Your Internet connection goes down, and so does your ability to call from extension to extension, even between extensions on your local network. This is a long-standing bug in Asterisk (exactly the sort of bug that drives people to try alternatives such as FreeSWITCH) but let’s say that for whatever reason you need to stick with Asterisk, so you’d like to find a way to make that bug go away.  Without going into all the technical details, the reason that calls fail is that Asterisk can’t access a DNS server.  I’ve read several reports that say the easiest solution is to install the BIND DNS server  on the same machine as your Asterisk server.  If you are also running Webmin on the server, installing and configuring BIND is a relative piece of cake.  So here’s how it’s done.  Please note that most of the images below can be enlarged by clicking on them, and that I have installed the StressFree theme in Webmin, so if it looks a little different from what you’re used to seeing, that’s probably why.

To start with, log into Webmin, click on “Servers”, then click on “BIND DNS Server” (if you don’t find it there, try looking in “Un-used Modules”):

Webmin Servers page — click on "BIND DNS Server"

Assuming you have not previously installed BIND, you’ll get a screen like this.  Just click where it says “Click here”:

Webmin BIND DNS Server error page — click where it says "Click here"

You will then see this screen come up as BIND is installed. Just let it run to completion and (assuming it installs successfully) click on “Return to BIND DNS Server” at the bottom of the page:

Webmin "Install Package" page — click on "Return to BIND DNS Server"

Next, because you don’t yet have an /etc/named.conf file, you’ll see this page.  Click the button for “Setup nameserver for internal non-internet use only” (don’t worry, we’ll fix it in the next steps), then click the bar that says “Create Primary Configuration File and Start Nameserver”:

Webmin — click "Setup nameserver for internal non-internet use only"

At this point BIND is installed and running, but it probably isn’t doing what you want it to, and your system isn’t using it. So the first thing we need to do is tell it where to go when it needs to do a DNS lookup. You should be seeing a page that looks like this — click on “Forwarding and Transfers”:

Webmin BIND DNS Server page — click on "Forwarding and Transfers"

When you get to the following screen, check “Yes” next to “Lookup directly if forwarders cannot?”  You also need to enter one or more addresses of DNS servers that BIND can access when it needs to pull a DNS record.  You might want to give some thought to which DNS servers you want to use, and in what order, before you start entering them. You can enter up to three IP addresses of DNS servers, and then click “Save”. This will throw you out to the previous screen, and if by some chance you want to enter even more DNS servers, you can click on “Forwarding and Transfers” again to come back and enter up to three more servers, until you are finished.  In this example, I have already entered the IP addresses of my router’s DNS Server as the top priority pick,  followed by two Google DNS Server addresses.

Webmin — BIND DNS Server — Forwarding and Transfers page

Once you have done this, you are through configuring BIND directly, but there are two more things we need to do. The first is to make sure that the BIND server starts each time we restart the machine. To do that, go to Webmin’s “System” page and then click on “Bootup and Shutdown”:

Webmin System page — click on "Bootup and Shutdown"

This is a long page so I’m not showing all of it — what you have to do is find the entry for named and check the box next to it:

Webmin Bootup and Shutdown page — check the box next to "named"

Then go to the bottom of the page and click “Start on Boot”:

Bottom of Webmin Bootup and Shutdown page — click "Start on Boot"

At this point BIND is running, and should be using the correct DNS servers, and is set to start at bootup, but your server still isn’t using it for its DNS queries. To get it to do that, go to Webmin’s “Networking” page and click on “Network Configuration”:

Webmin Networking page — click on "Network Configuration"

Once on the Network Configuration page, click on “Hostname and DNS Client”:

Webmin Network Configuration page — click on "Hostname and DNS Client"

Once on the Hostname and DNS Client page, what you need to do is make the first entry in the DNS Servers list 127.0.0.1. If you trust BIND to always be operating, that’s the only entry you need. I didn’t quite trust BIND that much (actually, what I didn’t trust was my ability to set this up correctly) so I set the DNS server in the router as the secondary DNS address. You could use any DNS server as the secondary, or you could choose to just enter the 127.0.0.1 address to use BIND and let it go at that. Personally, I feel a lot more comfortable having a “fallback” DNS. Don’t forget to click “Save” when you are finished making changes here:

Webmin Hostname and DNS Client page - 127.0.0.1 must be first DNS server

That’s all there is to it, as far as I know (if you think I’ve missed anything or done something wrong, the comment section is open!). If you’re like me, the next question you will have is, “How do I know it’s working?” And the easiest way to do that is to go to a Linux command prompt and “dig” some site you have not been to recently twice in a row. Here’s an example, using cnn.com — the part we are interested in is in red:

dig cnn.com

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_5.3 <<>> cnn.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8274
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 13, ADDITIONAL: 9

;; QUESTION SECTION:
;cnn.com.                       IN      A

;; ANSWER SECTION:
cnn.com.                287     IN      A       157.166.224.25
cnn.com.                287     IN      A       157.166.224.26
cnn.com.                287     IN      A       157.166.226.25
cnn.com.                287     IN      A       157.166.226.26
cnn.com.                287     IN      A       157.166.255.18
cnn.com.                287     IN      A       157.166.255.19

;; AUTHORITY SECTION:
.                       76691   IN      NS      i.root-servers.net.
.                       76691   IN      NS      j.root-servers.net.
.                       76691   IN      NS      k.root-servers.net.
.                       76691   IN      NS      l.root-servers.net.
.                       76691   IN      NS      m.root-servers.net.
.                       76691   IN      NS      a.root-servers.net.
.                       76691   IN      NS      b.root-servers.net.
.                       76691   IN      NS      c.root-servers.net.
.                       76691   IN      NS      d.root-servers.net.
.                       76691   IN      NS      e.root-servers.net.
.                       76691   IN      NS      f.root-servers.net.
.                       76691   IN      NS      g.root-servers.net.
.                       76691   IN      NS      h.root-servers.net.

;; ADDITIONAL SECTION:
b.root-servers.net.     386178  IN      A       192.228.79.201
d.root-servers.net.     402826  IN      A       128.8.10.90
d.root-servers.net.     230000  IN      AAAA    2001:500:2d::d
f.root-servers.net.     370827  IN      A       192.5.5.241
g.root-servers.net.     463754  IN      A       192.112.36.4
h.root-servers.net.     374116  IN      A       128.63.2.53
h.root-servers.net.     517382  IN      AAAA    2001:500:1::803f:235
j.root-servers.net.     185528  IN      A       192.58.128.30
j.root-servers.net.     578747  IN      AAAA    2001:503:c27::2:30

;; Query time: 26 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Sep 16 12:45:41 2011
;; MSG SIZE  rcvd: 512

# dig cnn.com

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_5.3 <<>> cnn.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8277
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 13, ADDITIONAL: 9

;; QUESTION SECTION:
;cnn.com.                       IN      A

;; ANSWER SECTION:
cnn.com.                223     IN      A       157.166.255.19
cnn.com.                223     IN      A       157.166.224.25
cnn.com.                223     IN      A       157.166.224.26
cnn.com.                223     IN      A       157.166.226.25
cnn.com.                223     IN      A       157.166.226.26
cnn.com.                223     IN      A       157.166.255.18

;; AUTHORITY SECTION:
.                       76627   IN      NS      c.root-servers.net.
.                       76627   IN      NS      d.root-servers.net.
.                       76627   IN      NS      e.root-servers.net.
.                       76627   IN      NS      f.root-servers.net.
.                       76627   IN      NS      g.root-servers.net.
.                       76627   IN      NS      h.root-servers.net.
.                       76627   IN      NS      i.root-servers.net.
.                       76627   IN      NS      j.root-servers.net.
.                       76627   IN      NS      k.root-servers.net.
.                       76627   IN      NS      l.root-servers.net.
.                       76627   IN      NS      m.root-servers.net.
.                       76627   IN      NS      a.root-servers.net.
.                       76627   IN      NS      b.root-servers.net.

;; ADDITIONAL SECTION:
b.root-servers.net.     386114  IN      A       192.228.79.201
d.root-servers.net.     402762  IN      A       128.8.10.90
d.root-servers.net.     229936  IN      AAAA    2001:500:2d::d
f.root-servers.net.     370763  IN      A       192.5.5.241
g.root-servers.net.     463690  IN      A       192.112.36.4
h.root-servers.net.     374052  IN      A       128.63.2.53
h.root-servers.net.     517318  IN      AAAA    2001:500:1::803f:235
j.root-servers.net.     185464  IN      A       192.58.128.30
j.root-servers.net.     578683  IN      AAAA    2001:503:c27::2:30

;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Fri Sep 16 12:46:45 2011
;; MSG SIZE  rcvd: 512

Notice how on the first run, it takes 26 msec to do the lookup, because BIND doesn’t have that address cached yet, whereas on the second run it only takes 1 msec to do the lookup!  Could that perhaps improve system performance?  I’ll bet it could! And the SERVER line tells us that it is indeed using our BIND server (127.0.0.1) – if it were using, say, our router’s DNS server then that line would show this:

;; SERVER: 192.168.0.1#53(192.168.0.1)

The idea here is that when your Internet connection takes a dive, Asterisk will still be finding a working DNS server and therefore won’t tank.  That, at least, is the theory I’ve seen on several web sites.  The ONLY thing I am showing here is how to set up BIND using Webmin, and I won’t even guarantee that I’m doing that 100% correctly.  I definitely do not guarantee that it will actually work as intended — you’ll have to test that yourself.  Doing a real test would mean disconnecting your cable or DSL modem, etc. from your router for several hours or days to see if the phones continue to work, and in most households or businesses that idea will go over like a lead balloon.  However, feel free to give it a good test if you like and report the results in the comments.

You may wonder why I selected “Setup nameserver for internal non-internet use only” in the fourth screenshot.  Obviously, that description is not entirely accurate.  The real difference is that if you select that instead of the default “Setup as an internet name server, and download root server information”, it won’t create a “root” DNS zone, which you simply don’t need for this application.  You can use the other option if you want to, but it will download additional information and increase the complexity of your setup.  Either way, you should be able to access the Internet, because we set up DNS forwarding.  If by some chance this BIND server is going to act as a nameserver for your entire network, and you don’t mind the additional traffic and complexity (and it’s the additional traffic that scares me the most, since I have no idea what it’s actually downloading nor how often it’s doing it), then by all means feel free to use the second option.  All I will say is that I used the first. and it works fine, and I’ve seen at least one instance where this same thing is set up using a method other than Webmin, and except for the order of statements it uses an /etc/named.conf file that is identical to what Webmin produces when configured as I have shown here (in other words, no “zones” at all).  I’m just waiting for some Linux purist to say this isn’t the “right” way to do this but keep the goal in mind here — all we are trying to do is work around a bug in Asterisk that should have been fixed years ago, not set up a DNS server to feed an entire subnet.  But again, you can feel free to use whichever of the options you like — it should work either way.

(By the way, if after reading the above you have “setup remorse” — you know, that feeling you get after you’ve installed something that you should have picked a different option — you can get a “do-over” by simply deleting or moving/renaming /etc/named.conf.  If you then exit Webmin’s BIND module and come back in, it should see that named.conf doesn’t exist and start you over at the fourth screen shown above.  Of course, you will lose anything you have already configured from within that module.  If you originally selected the option to download the root server information, I think that’s at least partly stored in the file /etc/db.cache, so you could move or remove that file to make sure it’s not used, however I’m not sure if any other files are or were also downloaded.  That particular file is very small so I’m not worried about that one per se, it’s just that the way things are worded on a couple of pages I read, I don’t know if that’s all it downloads, or if at some point in the middle of the night it rises up and tried to cache all the DNS information for the Internet, or just exactly what it does.  Sometimes I wish people would just give a sentence or two of additional information, so you have a better idea of what’s the right thing to do when you’re setting up something like this.)

Now, if you are a True Linux Geek who somehow stumbled across this article, and are disappointed that it isn’t much more complicated, I’ll refer you to this page.  If you can figure all THAT out, you should be getting paid the big bucks as the networking expert that you are! 🙂

A real help for Linux users with bad memories: Aliaser — take control of your aliases on Linux

 

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.
Tux, the Linux penguin
Image via Wikipedia

Here’s a program that may be useful for those of you who, like me, sometimes find ourselves at a Linux command prompt trying to recall the syntax of a command we use frequently (because, you know, it would never have occurred to the designers of Linux to actually implement commands with names that have a clear meaning in plain English):

Alias are a great tool to help increment your productivity on the terminal with bash (or any shell program you’re using), but usually we are too lazy to think at what are the most common, or long commands that we use frequently and prepare an alias for them.

And so someone has done a small piece of software to do this job: aliaser

Aliaser helps you identify frequently typed commands and creates bash aliases for them. Aliaser analyses your bash history and helps you identify commands that you use frequently.

Full article (with installation instructions) here.

One thing they forgot to mention is that once you’ve added an alias, it won’t actually be available for use until you log out and then log back in.  Also, you can delete the aliaser file and temporary directory from your /tmp directory once installation is complete.  If you ever want to uninstall aliaser, just remove the three lines added to your .bashrc file, remove the ~/.aliaser directory, and remove the /usr/bin/aliaser file.

One way I find this useful is to make commands I can’t remember into ones that that I can remember.  For example, I did this:

aliaser add processes “ps awx”

The Linux purists are probably rushing to comment that I just turned a six character command into a nine character one.  Yes, BUT, I can actually remember the word “processes”, whereas I cannot remember the options I need to use after “ps” to get the output I want. The designers of Linux seem to not realize that some of us users have really bad memories.  Another use for this is turning arcane Linux commands into the equivalent Windows commands that you’re familiar with.  You could do this:

aliaser add dir “ls -al”

So that when you type “dir”, you get a directory listing similar to what you are used to.

If you can’t even remember the aliases you’ve created (yeah, my memory really is that bad some days), just use aliaser show to see all the aliases you’ve added.

How to give a particular extension or group of extensions access to a specific trunk or group of trunks for outgoing calls 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.
Dial Patterns that will use this Route
Dial Patterns section of new FreePBX Outbound Route

I’m going to lift a bit of preliminary text from a page on the FreePBX site entitled “How to give a particular extension different or restricted trunk access for outgoing calls“:

IMPORTANT: When implementing any sort of restrictions on extensions, using the method described here or any other method, please be absolutely certain that you do not inadvertently restrict access to emergency services numbers (such as 911 in the U.S./Canada)!

There is a recurring question that comes up every so often, regarding how to give one particular extension (or a group of extensions) access to a different trunk for specific outgoing calls, or perhaps to restrict access to a particular trunk. Usually this involves an extension that is accessible to people that might want to make calls that cost money, and you don’t want them to do that. But there are many other reasons to route calls differently for different extensions, while still keeping all extensions on the same system so they can call each other.

Usually when someone asks about this, a common suggestion is to use the unsupported third-party Custom Contexts module. While this module is very versatile and lets you have a high degree of control over what each extension may access, there are at least two downsides. One is that it’s not part of the official distribution and therefore, a future upgrade of FreePBX might “break” it.

(This is probably less likely now, because it appears some of the FreePBX developers have taken an interest in maintaining it, but it’s still not beyond the realm of possibility.)

The other issue is that you have to go through and check (and maybe change) all the priority dropdowns if you add, remove, or move a route, and that can get to be a pain in the butt very quickly if you are in the habit modifying your routes with any frequency.

The problem with this page is that although it discusses several alternatives to using Custom Contexts (and you may wish to read it just to learn about those other possibilities), it is getting rather dated and therefore does not mention the use of the fourth field in Outbound Routes, a.k.a the “CallerID” field, which is by far the easiest way to implement this.

Let’s say you have an existing outbound route, over which your outbound calls normally travel, and it has a particular selection of trunks.  But you also have an extension, let’s say it’s extension 234, and you want it to use a different trunk or group of trunks.  In FreePBX 2.9 or later, all you have to do is this:

  • Go to the settings page for the Outbound Route that is currently used for outgoing calls.
  • At the bottom of the page, next to the “Submit Changes” button, there is a new “Duplicate Route” button.  Click on “Duplicate Route”.
  • Move the duplicated route to be higher in priority than the original route (it should appear just above the original route in the right-hand column).
  • Optionally rename the duplicated route to something more to your liking.
  • In the duplicated route, under “Dial Patterns that will use this Route“, add the extension number (or pattern matching a group of extensions) to the fourth (CallerID) field of EVERY dial pattern on the list.  Or, if using the Swiss Army Knife Module and you have checked the “Turn On Old (Pre 2.8) Dial Plan Textbox” checkbox (EDIT: or if you have FreePBX 12 or later, and under Settings | Advanced Settings, in the “GUI Behavior” section you have set Enable The Old Style FreePBX Dial Patterns Textarea to True), then add the extension number or pattern to the end of every existing pattern, separated by a forward slash.  As an example, an existing pattern of 1+NXXNXXXXXX would become 1+NXXNXXXXXX/234.  Again, you must do this to every pattern in the pattern list.
  • And finally, in the duplicated route, change the the “Trunk Sequence for Matched Routes” to include only those trunks that you want that extension or group of extensions to use.

If there are additional Outbound Routes for which you want to change the trunk selection for the same extension, repeat the above, starting with the other outbound route(s).  If you have additional extensions and you want one or more of them to have different trunk usage, repeat the above, using the different extension number(s) in the CallerID field and the different trunk selections.

If you want to block an extension’s ability to make toll calls, use the same procedure but only give them access to an ENUM trunk.  ENUM is pretty broken then days, it it would be rare for a call to actually complete, but if it does it’s not going to cost you anything.  This particular usage is discussed in more detail in “How to block a single extension’s ability to make outgoing toll calls in FreePBX“. (EDIT: In the most recent versions of FreePBX you can simply not select any trunks at all in the “Trunk Sequence for Matched Routes” section of the Outbound Route, and then optionally select a failure announcement or whatever treatment you want to give the call in the “Optional Destination on Congestion” section.)

And again, please note that you can use a single extension number OR a pattern in the CallerID field.  For example, if you had a pattern like 1NXXNXXXXXX, you could do something like:

  • 1NXXNXXXXXX/100 – match on the pattern only if the call is from extension 100
  • 1NXXNXXXXXX/2[45]X – match on the pattern only if the call is from an extension in the range 240-259
  • 1NXXNXXXXXX/3XX – match on the pattern only if the call is from an extension in the range 300-399

And if you wanted to allow the call only if it came from extension 100, 240-259, or an extension in the 300’s then you could use all three of the above rules in the same outbound route.

I will offer my opinion that using the Swiss Army Knife Module and checking “Turn On Old (Pre 2.8) Dial Plan Textbox” is the only way to go if you happen to have several hundred dial patterns!  Well, maybe not the only way (you could export a .CSV file, edit it, and import it back in), but definitely the easiest, because you can simply cut all the patterns from the textbox and paste them into a text editor, then use search-and-replace to add the extension numbers, then copy the changed patterns from the text editor and paste them back into the textbox in the Outbound Route.  If the search-and-replace function supports regex matching then it’s easy – set the find string to n and set the replace string to /234n (assuming 234 is the extension number you want to add), and replace all occurrences (be sure to check the first and last lines to make sure they look as they should, in case there was a missing or extra newline character somewhere).

EDIT: We have been informed that the old-style textboxes are once again available in FreePBX 12 and later. You have to click on the Settings tab, then Advanced Settings, then find the “GUI Behavior” section and change the Enable The Old Style FreePBX Dial Patterns Textarea setting to True.

Related Articles:

The Linux equivalent of Little Snitch, ZoneAlarm, and similar per-application firewalls?

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.

EDIT: This article is very old and outdated. For more current information, see OpenSnitch: The Little Snitch application like firewall tool for Linux.

If you are a Mac user, you’ve probably heard of Little Snitch.  It’s a commercial (as in, not free) program that lets you allow or deny connections to the Internet from individual applications.  One reason for using such a program is to detect software that should have no reason to connect to the Internet nevertheless attempting to do so.  For example, you download a free screensaver (dumb move to start with) and it sends all the personal information it can find on you to some group of hackers on the other side of the world.  A program like Little Snitch would let you know that the screensaver  is trying to connect to the Internet, and allow you to deny that connection.  In the Windows world, I believe that ZoneAlarm has a similar capability, and it’s also a commercial (as in, not free) program.

Leopard Flower personal firewall for Linux OS screenshot
Leopard Flower personal firewall for Linux OS screenshot

It appears that these is a similar program for Linux users, and it IS free!  It’s called Leopard Flower and it’s described as a “Personal firewall for Linux OS (based on libnetfilter_queue) which allows to allow or deny Internet access on a per-application basis rather than on a port/protocol basis.”

Looking at the screenshot it appears to have very much the same per-application blocking functionality you’d get in one of those other programs.  I have not personally tried it yet, but I wanted to create a post about it so if someday in the future I am trying to remember the name of this program, I’ll know where to find it (yes, this blog does sort of serve as my long-term memory!).  🙂

Since this article was originally published, I have been made aware of another similar application called Douane: Linux personal firewall with per application rule controls – here are a couple of screenshots:

Douane personal firewall for GNU/Linux screenshot
Douane personal firewall for GNU/Linux screenshot
Duane configurator screenshot
Duane configurator screenshot

The only downside to this one is that as of this writing the only available package is for Arch Linux but if you want to try to build it for a Ubuntu or Debian system, they provide a page showing the needed dependencies.

There is an older similar program called TuxGuardian but apparently is hasn’t been updated since 2006, so I have no idea if it will even work with current versions of Linux. And as for you Android users, try the NoRoot Firewall app.

If your Linux-based PC with NVIDIA graphics started booting to a black screen or text only, here is the fix — maybe!

 

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 NVidia as depicted in Crunc...
Image via CrunchBase

I’ve seen this happen several times now on Ubuntu-Linux based systems that have NVIDIA graphics.  What happens is that “Update Manager” pops up and tell you there are updates for your software, and you accept them.  It then tells you that your system has to be rebooted.  And when you do that, you get no video, or text only.  What probably happened was that the updates you installed included an update to the Linux kernel, and the NVIDIA graphics driver currently installed on the system was compiled against the OLD kernel.

Note that this generally can only happen if you manually updated the NVIDIA graphics driver at some point. If you always installed it from the standard repositories for your distribution, you’ll probably never see this issue. So a word to the wise — when you finally get around to doing an upgrade of your Linux distribution, try to avoid manually installing the NVIDIA graphics driver. Instead, let the distribution pull it from its repository. After that, you should not have this issue in the future. By the way, if you currently are running Ubuntu, we recommend upgrading to Linux Mint rather than a newer version of Ubuntu. Linux Mint is very similar to Ubuntu, but leaves out some of the things that users seem to hate about newer releases of Ubuntu. More to the point, they are not currently talking about switching their base graphics system from the X window server system to a new display manager, which I have a feeling might cause problems for some NVIDIA graphics users.

But if you’re not yet ready to do a full reinstall of Linux, the fix for this problem is easy IF you had the foresight to set up SSH access to your Linux system BEFORE the trouble started.  If you didn’t, and you’re not a true Linux geek, you may be kind of screwed.  So if you’re reading this and your system is working fine, and you haven’t yet set up SSH access, you may want to do that.  There are several sites that tell you how to do that; here are two that I found using Google:

Basic SSH Setup On Ubuntu 10.04 Lucid Lynx Using OpenSSH Server
SSH—OpenSSH—Configuring

If you didn’t do this beforehand, you may still be able to do it if you can get to a command prompt.

Anyway, the actual fix is to (re-)install the latest NVIDIA driver for your system. They will be compiled against the new Linux kernel and then everything should work fine. To find the correct NVIDIA driver, go to the NVIDIA Driver Downloads page, and use the dropdowns to select the correct driver for your system.  Download it to your local system, then upload it to your Linux PC (if you have SSH access working then you can use an SFTP client, such as WinSCP or Transmit, to upload your driver file).  Once you have it on your PC, from a command prompt navigate to the directory where you put the driver and then change the permissions to make it executable:

sudo chmod +x driver_upgrade_script_filename

Now try running the script (it should have a .run extension):

sudo ./driver_upgrade_script_filename

It should not complain that the Gnome Display Manager or KDE Display Manager is running (if it were, you wouldn’t be in a state of near-panic right now), but if you were just doing a regular update you’d have to do this when the GDM/KDM is stopped. For a guide that covers that scenario, see How To Install Official Nvidia Drivers in Linux, or just know that to stop the display manager,

sudo /etc/init.d/gdm stop

should stop the Gnome Display Manager, or if you’re using KDE then the command would be

sudo /etc/init.d/kdm stop

Most sources I’ve seen suggest that you answer yes to any questions the installer may ask. The only one I’d be cautious about is letting it create a new xorg.conf if you are using a customized one (which you may well be if you’ve used any of my previous HTPC-related articles). If you have edited xorg.conf, then I’d make sure you at least have a backup before letting the installer create a new one, so you can revert back to your custom one (or compare the two and insert your customizations into the new one) if necessary.

Under Ubuntu, you may get a message similar to “Provided install script failed”. That will happen every time you update the NVIDIA driver this way and it is normal. Just ignore it and continue the installation. If you get “Error locating kernel source”, run  sudo apt-get install kernel-source  from the command prompt, then run the driver upgrade script again.

When the installer has successfully finished, reboot the system and when it comes back up, hopefully you should be happy again!

How to send an e-mail notification when someone dials a particular number 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.

Someone in the PBX in a Flash forum wanted to know if there was some technique that could be used to get an e-mail alert if a user on the system dialed 911.  There are probably many ways this could be done, but here was the way I thought would work.  This has not been tested in a working installation so please note the disclaimer at the end of the article.  I DO NOT guarantee that this will work on your FreePBX installation!

EDIT (November 24, 2012): Another approach to doing this would be to add some custom dialplan to the [macro-dialout-trunk-predial-hook] context in extensions_custom.conf.  See How to use the FreePBX [macro-dialout-trunk-predial-hook] macro and regular expressions to blacklist or whitelist outgoing calls on all trunks for more information on this technique, which would allow you to easily detect outgoing calls to a particular number on just about any trunk with only a few lines of code, eliminating the need to create a CUSTOM trunk as shown below.  Either method will work, so do whichever you’re more comfortable with.

1. First, add a small additional context to /etc/asterisk/extensions_custom.conf (note that you will probably need to copy and paste this into a text editor to get the first line of the context complete and without line breaks where they shouldn’t be):

[custom-notify-email] exten => _X!,1,TrySystem(echo "This is to notify you that ${CALLERID(name)} at ${CALLERID(num)} has called 911" | mail -s "911 call notification" you@youraddress.com)
exten => _X!,n,Goto(from-internal,0000${EXTEN},1)
exten => h,1,Macro(hangupcall,)

Note that the first line of the context (not counting the context label line) contains the actual email to be sent.  Replace the various elements of the e-mail (body, subject, destination address) with appropriate elements for your situation. In the second line of the context, note that I’m prepending a four-digit code of  “0000” to the number dialed before sending it back into the dial plan.  This code can be anything you want and any number of digits you want, but it should start with something that a user would never dial when making a regular call.  Therefore, things like “0000”, “111111”, or even “*****” could be good choices, while “9876” would be a poor choice because a user might actually attempt to call a number such as “987-6911”.  One PBX in a Flash forum user reported that “0000” conflicted with Astridex in some way, so that’s why I’m taking pains to explain this.  Since the user isn’t expected to dial these digits, you could even use something like “010100001111”, just as long as it’s a code used uniquely for this purpose.

2. Create a CUSTOM trunk. Make the trunk name whatever you like, but for the Custom Dial String use:

Local/$OUTNUM$@custom-notify-email

When you set it up it should look like this:

CUSTOM trunk (here named Send-email-notification) sends calls to custom-notify-email context

3. Assuming you’re using this to monitor 911 calls, create a NEW emergency 911 Outbound Route that duplicates your existing 911 route (In FreePBX 2.9 or later you can click on the “Duplicate Route” button). In the duplicate (which should be right underneath the original in priority) change the dial pattern from 911 to 0000|911 (but if you used something other than 0000 in step 1, use the same thing here).  What this does is strip off the digits that were prepended to the number by the custom-notify-email context — this is done so you don’t create an endless loop. Note the pattern I have shown assumes you are using FreePBX 2.7 or earlier OR are using the Swiss Army Knife module to restore the pre-2.8 dial pattern text box in your Outbound Routes — if you haven’t done that then be sure you get each component of the dial pattern in the correct little box.

DUPLICATE of original 911 emergency route that strips prepend in dial pattern (route has been renamed to 911-strip-prepend). Note how Swiss Army Knife module restores textbox entry for dial patterns!

4. In your ORIGINAL emergency 911 Outbound Route, change the trunk selection to use only the CUSTOM trunk you created in step 2.

ORIGINAL 911 emergency route, with trunk selection changed to use CUSTOM trunk

That’s it. The call flow is as follows:

Someone dials 911, it goes to the original 911 outbound route, then to the custom trunk and from there to your custom context which sends the email, prepends 0000 (or the digits you have used instead) onto the number (for example, making it 0000911 internally), and sends it back to the from-internal dial plan. It hits the duplicate 911 outbound route which strips the prepended digits and sends the call to your original trunk selection for 911 calls.

I would STRONGLY urge you to make a test call and see if it all works as you expect, if your local 911 service allows you to do that (call them on the non-emergency number first to make sure it’s okay). See the disclaimer below!!

You could use this same technique for non-emergency calls, but you’d have to have an Outbound Route dedicated to just those calls (in other words, it should only contain dial patterns for the calls you are trying to monitor, and it needs to be higher in priority than any other Outbound Route that might ordinarily handle such calls.  Once you have that working you can apply the above technique, which among other things means you’ll be making a duplicate of that Outbound Route, and making adjustments to the original and the copy as described above.

Disclaimer: The above is just a suggestion of what SHOULD work, and should be considered UNTESTED. Do NOT rely on it until you have tested it yourself to make sure it works as you expect. I don’t guarantee it will do anything except take up more space on your hard drive, so it is solely up to YOU to make sure it works as you want.