VoIP

This is one of those new-fangled things I am not overly familiar with. Having come across the existence of it (see the wireless refit page) I have a need to find out more. First off, a bit of reading about the protocol until I am fast asleep and unable to take anything in. This is useless. Therefore I decided to take a more hands-on approach, and install my own server. Poor Thor having to cope with all this rubbish, his little drive is creaking under the weight of useless installations.

There's an open source solution called Asterisk which I download and compile. It doesn't, so, time to read the README. Several dependencies later I have a working Asterisk. There's a CLI which can be invoked by starting it with parameter -c, that seems like a good idea. "Help" gives help. Except it doesn't, because I have absolutely not the foggiest idea what any of the commands mean. I fiddle about with the config files to create some users, and burden several PC's in the house with the X-Lite software so favoured by my wireless visitor. It cannot, will not, absolutely refuses to, register these soft phones to the Asterisk.

I cast around for easier options, and come across the notion that there is a web-interface embedded in the Asterisk, which by default is not enabled. I enable it, and hey presto, the page takes forever loading. In other words, it doesn't load. Try a different interface, then. I downloaded VoiceOne which is supposed to do the same sort of thing.

Before long I was knee-deep in problems. MySQL is one of those things that completely escapes me, whoosh straight over the head. I actively switch off when I see/hear mention of it. A vague, 1/4 century-old, memory of something called "Boreland" (?) comes to me whenever this happens but I daren't probe the actual cause. Be this as it may, I am able to copy and paste type command into terminal screens, and I followed everything to the letter, but it just did not work. Googling the actual errors generated lead to the installation of various other bits and bobs, but no luck.

Next day, back to the embedded GUI. Usually when weird errors are achieved in Linux, it's something to do with permissions, so I chmodded the whole bleeding caboodle to 777, and behold: a semblance of a web interface. Except that this here Asterisk thing was constantly restarting, according to the interface. Certainly the interface was constantly reloading. None of the errors generated by the program made any sense as to cause, and packet sniffing showed a lot of "permission denied" stuff. At one point I just tried to click on one of the links on the admin page, quickly, before the restart, and lo & behold, this worked!?! The restarting stopped, and I was able to look at all the options, and add some users for my X-Lite pc's.

Now the X-Lite can call the PBX. Dial various numbers to hear recorded messages. Wonderful, but the clients cannot register.

[Mar 12 12:38:56] WARNING[6583] config.c: Realtime mapping for 'sippeers' found to engine 'mysql', but the engine is not available  

This is the error that occurs -- also just about the only error now. (Apart from

[Mar 12 12:38:56] NOTICE[6729] rtp.c: Unknown RTP codec 126 received from '192.168.0.230'

but I suspect that is the fault of the client not the Asterisk.)

Any takers? I have Googled it to death now, and even went as far as to reinstall the whole thing, but this is just not going away. It's clearly a database problem, and a database permissions problem at that, but I can't see how to rectify. What I am going to do is install a fresh Linux on a fresh virtual machine, and try it all again.

Links

The Asterisk software: http://www.asterisk.org/

VoiceOne GUI: http://www.voiceone.it/

VoiceOne installation guide: http://docs.voiceone.it/index.php/Quick_Install_Guide

O'Reilly book "Asterisk: A Bare-Bones VoIP Example": http://www.onlamp.com/pub/a/onlamp/2003/07/03/asterisk.html?page=1

O'Reilly book "Asterisk: The Future of Telephony" [god forbid]: http://downloads.oreilly.com/books/9780596510480.pdf

Asterisk RealTime: http://www.voip-info.org/wiki-Asterisk+RealTime

Addons: http://www.voip-info.org/wiki-Asterisk+addons; http://www.asteriskpbx.com/node/48345

 

 

All Your RTP Are Belong To Me

aka Some thoughts about VoIP

I have never used VoIP. The first time I really thought about it was when the Speedtouch router arrived from ISP Be and it had ports for phones in the back of it. Two of them no less. First thought was, why the hell would I want to place calls through my internet connection? No thanks! Be was going to set up their own VoIP provisioning apparently, though I haven't heard much about that lately. Second thought was.. well it never came. The VoIP was ignored until the man with the SIP request packets came knocking. Now that I have all of his calls through this network on tape so to speak, I am cured from any tendency to want to use VoIP for anything other than playing on the LAN.

These people (business name witheld, they reckon they're going to be big some time soon, which means they will get lawyered up no doubt) have got this VoIP provisioning as a business. They are doing this for real, they've already got a couple of users (I know who they are, because it tells you on the admin page of the PBX) and are about to haul in a large nation-wide contract. What they are probably not telling these potential customers is that they log in to the admin using clear text, and whatever wireless network comes to hand.

The admin page lets you do all sorts of interesting things, taping calls for instance. I could make my own user on their system, so that I can log in independently at will, record conversations, and download them to my own computer. I could use this to obtain privileged information, as this is likely to be forthcoming if they actually do get this contract. Stuff to do with perps and court cases and whatnot. I could then use this to, well I don't know, because I am basically a very nice person. But if I can do this, so can anyone, especially someone who's not so nice.