With the preponderance of cellphones, the traditional telephone network is close to extinction. Cell phones can not be used everywhere. More and more buildings will be secured from outside eaves dropping, so some kind of more traditional phone service will be needed. Using the computer connections via voip (voice over ip) can be away to compete. I will show what we did with various voip software and hardware devices. One other thought to consider is that the phone company wants to get rid of traditional phone lines. So might as well as get ready now.
There is a variety of IP phones available. Most are all in one unit. We already had phones and the ip phones at the time we looked at them were just too expensive. So I opted to get some analog to digital interfaces very cheap. All of the units shown would originally not work with the server we had. The firmware had to be a generic version not tied to a voip company. I installed the alternate firmware. You can see both the traditional phone cable and the ethernet cable so both have to be connected. There are some wireless units available, but cable is cheap. Some interfaces can act as a router like the larger unit in the picture. You could add other ip phones or networked equipment.
We will be testing two versions (maybe more) of the voip server. The two main servers will be winxp home with 3cx (requires a recent Microsoft operating system) and trixbox (includes centos linux). We will also use firmware modified d-link voip router, linksys pap, and packet8 analog to digital converters so we can use existing standard analog phones for the project. I will be also using a low end fxo card (Allows your system to act like a real old fashioned telephone) in the server for live access to existing phone lines.
We also may add a wireless access point that only certain devices can access the network. Most modern phones now have wireless features now. This can be done through using special electronic keys and mac address limitations. Mac (media access control addresses) have nothing to do with Apple branding. They are a sort of device serial number that is special to each networking device such as a nic (network interface card) or any other apparatus that can connect to a network. It is almost like letting in only people with the right badge number at a gate. More about all that later.
Some voip terminology to wet your appetite:
* VoIP – Voice over Internet Protocol (also called IP Telephony, Internet telephony, and Digital Phone) – is the routing of voice conversations over the Internet or any other IP-based network.
* SIP – Session Initiation Protocol – is a protocol developed by the IETF MMUSIC Working Group and proposed standard for initiating, modifying, and terminating an interactive user session that involves multimedia elements such as video, voice, instant messaging, online games, and virtual reality.
* PSTN – the public switched telephone network – is the concentration of the world’s public circuit-switched telephone networks, in much the same way that the Internet is the concentration of the world’s public IP-based packet-switched networks.
* ISDN – Integrated Services Digital Network – is a type of circuit switched telephone network system, designed to allow digital (as opposed to analog) transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds, than available with analog systems.
* PBX – Private Branch eXchange (also called Private Business eXchange) – is a telephone exchange that is owned by a private business, as opposed to one owned by a common carrier or by a telephone company.
* IVR – In telephony, Interactive Voice Response – is a computerised system that allows a person, typically a telephone caller, to select an option from a voice menu and otherwise interface with a computer system.
* DID – Direct Inward Dialing (also called DDI in Europe) is a feature offered by telephone companies for use with their customers’ PBX system, whereby the telephone company (telco) allocates a range of numbers all connected to their customer’s PBX.
* RFC – Request for Comments (plurals Requests for Comments but RFCs) is one of a series of numbered Internet informational documents and standards very widely followed by both commercial software and freeware in the Internet and Unix communities.
3cx setup (The product may have changed since these videos which were not done by us).
Trixbox setup (the product may have changed since this video)
We still have to talk about what we did, but at least you have some background after these videos.
Asterisk and some of it’s companion programs are changing dramatically, so we are waiting till things settle down before doing another install. I just added a second drive to our Microsoft box and converted it to be a linux server for the time being. so I will concentrate on the linux configuration. The three videos for the Microsoft configuration should suffice. We are actually going to try to use trixbox 2.8. Also plan to add asterisk to a router that uses openwrt as a test. Bought an inexpensive router and installed OPENWRT, but need to add the asterisk module.
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