What is the best way to get started using Asterisk?

Question

I'm interested in learning more about Asterisk (open source PBX) so I thought I would try building a "hobby" system for my home. Just play around with getting a juiced up voicemail system going for my family. That is, until I found out that a TDM11B kit from Digium costs over $500(!) if I want to get an FXO/FXS card with echo cancellation.

My question(s) are: what's the best way to go about learning Asterisk? Moreover, if I just want to get a souped version of voicemail going at home is there way I can do it without having to buy an expensive card to hook into the PSTN?

thanks,

• John

Answer 1

I know of some people using a bunch of winmodems (some of them have Linux support now, mostly thanks to reverse engineering) and hooking them into the phone lines. Of course this is not as cool as having a trunk (if I remember the terminology correctly; this was a long time ago) at home, but it's definitely very cheap. :-)

Answer 2

Perhaps start at http://www.asterisktutorials.com/

Answer 3

You shouldn't need a card with hardware echo cancellation - for home use you should be able to get the standard tdm11b for approx £115 and use software echo cancellation. Alternatively you can get similar 'copycat' products very cheaply off ebay or standard online stores (openvox is one of these).

Another way to go is to get a separate adapter such as a SPA-3000 with one FXS & one FXO.

Probably my advice would be to ditch TDM altogether though and get a SIP account with the provider of your choice, and then either a pure SIP phone or an adapter such as a Linksys PAP2

If you're interested in really learning asterisk then I'd stay away from the GUI versions (trixbox or AsteriskNow), you'll have a steep learning curve but once you 'get it' you'll have a far better understanding than you would with the GUI.

Answer 4

Thanks to Chris's suggestion, I searched for winmodems and asterisk, which (eventually) turned up this post. In essence, buy a winmodem with a specific chip on it, and then remove a pair of resistors (to set the vendor ID to something Asterisk will recognize), then add that card to your PC.

It's something I now plan to do also :)

Answer 5

I started using Asterisk for my house with a X100p clone and a PAP2 that I bought from ebay for ~20$ each and they work pretty well for a home system.

Also the best site find documentation and guides for asterisk is http://www.voip-info.org/

Answer 6

Keep it simple. There are many people that seem to be into Asterisk but come from an "old guy" telco mentality. Some people on the net will tear you down for experimenting with such a system and not doing it right. Who knows why... anyway on to the knowledge part...

Get trixbox (simple, easy to set up), don't worry about PSTN/FXO/FXS, signup with a VoIP provider (I use Faktortel but I'm in Australia). They have heaps of doco on how to set it all up with your own Asterisk server. Basically, the idea is that you get a new landline number that's actually with your VoIP provider. Your Asterisk logs into the VoIP provider system and any calls to your landline number gets routed to your Asterisk box.

You can hook up a softphone to it initially while you're experimenting, and then later upgrade to a hardware VoIP phone like the Linksys SPA941.

You'll need a decent uplink connection and QoS, so it's not all simple fun and games, but dealing with PSTN I've found to be more trouble than hooking directly to a VoIP provider over the Net. The best thing is you can receive calls to your landline number no matter where you are over an Internet connection.

I hope all that makes sense. Asterisk can be like going down the rabbit hole. Good luck!

Answer 7

I'm with Dan Harper.

Don't worry about interfacing with analog telephony equipment to start. Instead, you can set up an asterisk box on an old linux pc and get connected with a VOIP Service Provider. You can get a phone number for as little as $2/month. Voip-info has a huge list of them. I'm from Ottawa, Canada and I use Unlimitel.

After setting up your asterisk box to connect to your VOIP Service Provider, use a software SIP Phone (X-Lite is a popular one). If you want analog phones in your house to connect to your asterisk box you can get an ATA (analog telephone adapter) quite cheaply. I recommend the Grandstream Handytone 286.

Start by learning how to modify the standard config files (iax.conf or sip.conf) to connect to your VOIP Service Provider. Learn how extensions.conf works to create a simple dialplan. Modify sip.conf to allow your soft phone to connect. Once you've done that you're off to the races. If you're familiar with perl the Asterisk Perl AGI interface is a good tool to allow you to create very dynamic Asterisk Applications.

As far as resources to further your asterisk knowledge:
Asterisk: The Future of Telephony - Fantastic O'Reilly book given out free by Digium.
Voip-info.org - Great Website with tons of asterisk stuff

Good luck!

Answer 8

In a addition to the sites already mentioned, here are a few more you might want to check out:

http://www.asteriskguru.com/

http://www.nerdvittles.com/

Answer 9

Hello. Here are few resources that helped me a bunch:

http://www.the-asterisk-book.com/unstable/

I do agree that there's a lot of value with building Asterisk from scratch. I had some successes building Asterisk using this virtual machine. (CentOS)

http://www.vmware.com/appliances/directory/1029

Asterisk installs pretty well on Ubuntu as well. In my case, I focused on learning SIP.

Answer 10

There are a few books available for free on the net dealing with Asterisk.

http://www.the-asterisk-book.com/unstable/

and

http://astbook.asteriskdocs.org/

If you find them useful though, consider picking up a printed copy to support the Asterisk community!

Answer 11

As an aside, if you're using analog phones for extensions, test echo with them. Some analog plain phones generate an awful lot of echo on the opposite side of a VoIP conversation.