AboutGerry Magill Expertise I am a Software Architect employed by a large multi-national communications company providing VoIP and tradtional TDM communications to Enterprise customers.
Experience
Past/Present clients IBM, SBS, Siemens, KPMG, Bank Berlin, Commerzbank
Question QUESTION: I have been reading up on Voip and Sip and would like to get started using these technologies.
My broadband connection is cable at failry high speeds. What I would like to do is use an ip phone like the Cisco or he sipura phone lines.
My question is,
1) I guess I need a Voip provider? correct?
2) usually the Voip providers connect their service to an adapter so that the analog phones in the house works. How do I connect an ip phone to a Voip provider service?
3) If I buy a few ip phones touse inside my network do I even need a voip provider or will it just work as an intercom in my internal network?
Thanks
ANSWER: Welcome to the exciting world of SIP!
1) Yes, you will need a SIP VoIP provder. Choose one carefully based upon where and when you call. They all have similar monthly prices but they differ greatly in what you can do for that monthly rate. If you just want to try it out first, I can let you access my system.
2) Yes, VoIP providers will normally sell you an analog adapter but it will only allow you to connect your analog phone and nothing else. You only get one number from them and thus can only connect one device.
3) If you plug in multiple analog phones to the analog adapter it will work as it does today. When one phone goes off hook, all others can listen in, but only one can make a call at any one time. If you choose to hook up multiple IP phones, they will not work together without a local proxy at your home - similar to a local home phone system that allowed you to call between rooms in the traditional TDM world. So a provider will only let you connect one IP phone to their service.
To get around that, Asterisk was invented (http://www.asterisk.org). This is a piece of free software that you can download from the internet and load on a PC in your home. You then hook all of your IP phones to this proxy and assign each one a private number of your choice (i.e. 201, 202, 203, etc.) You can then make calls between the IP phones and you can also hook Asterisk up to your SIP provider. So the provider only sees one device - your Asterisk box. However, by dialing "9" or some pre-defined digit, you can access the outside line from any phone and make a call. This also has the advantage that you can make two calls at the same time. A SIP provider will allow that but it will not permit two devices - thats why you have to use the Asterisk box to proxy the calls.
So while your daughter is talking for hours on the phone to her friends, you can still make a receive calls on the second line.
Let me know what you decide to do.
Regards,
Gerry.
---------- FOLLOW-UP ----------
QUESTION: Thanks Gerry
Your answer cleared up many questions I had. I am not sure what you mean by accessing your system for trying it out. How is that done?
My next question is, if I get a voip provider and he supplies me with an analog adapter to plug in my analog phone line and I have Asteric box with a hook into the SIP provider
1) if someone calls me with a POTS line I guess the call
goes through the analog adapter, does that mean I cannot pick it up at the ip phones?
2) Can someone call me with a SIP phone? or does the call have to go through the ATA adapter?
3) Finally to get started I guess I would need 2 ip phones and a version of asterik. Any specific recommendations?
Answer I have my own asterisk server on the internet that you could connect to with an IP phone or analog adapter, if you had one. You could then try it out and decide then if you wanted to committ to a monthly fee for a SIP provider of your choice.
I use Broadvoice (www.broadvoice.com) for my outgoing calls. If you want I can send you a referral.
The way you hook up is you connect the Asterisk box to your home network (using a home router). You hook up your Asterisk box to the SIP provider, instead of their analog adapter. Broadvoice allows you to do this and will give you a reduced rate for "Bring your own device" hook ups. Then you hook up your IP phones to the home router and point them to the Asterisk box for service (this is done via an easy to use web browser interface that the phone provides you for administration purposes).
When a POTS line calls you, the call comes into the Asterisk box first. From there you decide what you want to do with that call, i.e. route it to one of your IP phones or to all of them at the same time.
Your analog adapater (if you choose to have one), is also then pointed to the Asterisk box just like your IP phones are.
Asterisk allows you then to decide what you want to do with inbound calls - and the choices are phenomenal. You can route to an automated attendant (Asterisk provides this functionality for free) which will ask the user who they want to talk to and give them options. Then the calls is routed to the correct IP phone (i.e. daughter, son, office, kitchen, etc.) Or it can get routed to each phone in a hunt group fashion, ringing each phone in a pre-defined sequence for a pre-defined time. You can also have it forward to an internal voice mail system on the Asterisk (again for free). When a user leaves a message it will even forward that message on to you as a wave file attached to an email... the options are mind boggling.
If you want cheap devices that work well, I'd go to the grandstream.com website (http://www.grandstream.com/products.html). They have all kinds of IP phones there and analog terminal adapters. You should find one to fit your budget. Once you decide on a model then go to pricegrabber.com or google and find a vendor that sells them online. You cant purchase directly from the grandstream.com website, but you will find great prices anywhere.
If you want help choosing the right device, let me know.
