While I’m sure it’s possible, how easy would it be for someone who’s fairly familar with Linux to set up a box that would allow a 4 person startup to have voicemail and what seem like extensions at a professional company but are really just forwards to personal cellphones? Alternatively, what’s a better setup/ what am I not thinking of? I’m planning on a Linux box attached to a broadband connection.
How easy would it be??? (I hate cliches, but…) How long’s a piece of string?
Personally, i’d find it quite easy. However, i wouldn’t like to guarantee the quality of it with 4 (or 6, or, 10?) simultaneous incoming calls, along with 4 of those calls being forwarded out of the system. But whether you’d find it easy or not would depend on how long you’re prepared to spend learning your way around asterisk before you get it to work - among other things.
That’s an impossible question to answer! What’s a better setup, depends entirely on your requirements and resources - and, to probably quite a large extent, where in the world you are.
You’ve explained exactly nothing about what you’re trying to do, really. Why mobile phones, for example? What’s the general setup of the organisation? What country are you in? What bandwidth broadband connection? Etc…
Sorry for my ignorance on this topic. Where can I find what kind of affect each successive call has on call quality in the documentation? The little I’ve plowed through has been overwhelming (I realize that’s because this can do so much).
In the US with (currently) a 4 megabit cable connection. Mobile phones because the whole thing’s rather virtual, at least for the moment. There isn’t an office at all, but we’d like to give the impression of being a professional shop right off the bat. I don’t know we’d need to actually run the calls through Asterisk; I’d like to provide voicemail for all of us but push actual calls onto the cell phones themselves in the interest of bandwidth (if that’s possible/ sensible).
To get an idea of bandwidth per call, have a read of
However, it’s fairly complex because, of course, bandwidth depends on which codec you’re using. And which codec you use may depend on your ITSP (internet telephony service provider). I’m assuming you’d want to do this through an ITSP, rather than using POTS or ISDN.
Let’s say, for example, that you’re using an ITSP for both incoming and outgoing calls. And let’s assume that ITSP supports the gsm codec. That codec seems a reasonable option, but you could possibly get better results from g729 (which you’ll have to pay a licence fee for each channel you’re going to use it on) or something else.
Anyway, you’ve got the incoming call (from the customer) - at about 13kbps plus the outgoing call (to your mobile) - also at 13kbps. However, those are, i think, raw bandwidths - once it’s been sent down your broadband connection it could be up somewhere around 40kbps each way. I’ve come across the figures for this somewhere, but i can’t remember where now!
Given that there could be up to 4 of those going on, you may need at least 160kbps for those calls. Then if a few more calls come in at the same time, you could need another 160kbps, say.
Now that may not seem like much - compared with 4Mbps, anyway - but it’s not a simple matter of just squeezing so many bits down a pipe and not worrying about what order they come out the other end in. It depends a lot on your ISP’s service and various other things. Latency makes a big difference to quality with VOIP traffic.
This is just an outline of how to work it out - don’t take those figures as gospel! There’s lots of information on this topic kicking around on the internet. Start with those URLs above and keep reading.
One way to find out, of course, is to give it a try! I’d guess that - depending on what your broadband connection’s upstream speed is - you’d probably be able to get it to work acceptably on this sort of scale.
You need to check out ITSPs that will provide the service you want and see what sort of prices they’re going to charge you for DID (direct indial) numbers and for calls to mobiles. The charges for calls to mobiles may help you decide whether you want to route the calls to the mobiles through your asterisk server or whether you want to just do voicemail on the server, along with (say) a message that if the caller wants to talk to a person, they can call this mobile number…
If i was going to do something like this, i’d start by setting up asterisk, getting an account with an ITSP - including a DID number - and doing a bit of testing. It will definitely work, but what counts is whether or not the resulting call quality and costs are acceptable to you.
So what you’re saying is, I probably shouldn’t count on using this on the same line my wife’s downloading a Bittorrent file while I’m on X-Box Live?
Thanks for the info. This is a great start. My current broadband provider (Comcast) is supposedly offering VoIP at some point (or may already be doing so). Should I get a DID through them or am I better off with someone like Vonage that’s a dedicated provider?
From experience, i’d say it would pay to shop around. Unfortunately, it may be necessary to try a few different ITSPs before you find one that you’re happy with.
I’m in Australia and the situation’s probably a bit different here (although maybe not) and i’ve got accounts with 3 different aus ITSPs (as well as 3 european ones). One of the aus ITSPs (Oztell) has such bad call quality it’s been completely unusable - i don’t really know why. The two others i use all the time, although one (ATP) is better than the other (Freshtel) (quality-wise, at least).
Of the european ones, one in particular stands out (Sipgate) - for price and for quality of service. One of the others (Gossiptel) seems to be a bit unreliable. And the third one (Voipgate) seems to give slightly lower quality - and slightly higher prices - than Sipgate. Although i think i’m using a cheaper rate call service with them, which could account for the quality difference, i’m not sure.
They all offer different services and different prices and pricing structures. To find the best one for your needs, you may need to try out two or three first. You will certainly need to do some research and find out what some of them offer and what they charge.
As well as the 6 ITSPs i’ve got accounts with, i’ve signed up for a couple of others at different times, but never got past checking out the basics of their service - i.e., the free parts. Generally, to test them out properly, you’re likely to have to pay them some money - which will probably mainly be call credit. Unfortunately i had to pay AU$20 to find out Oztell aren’t any good!
Just remember that with a cable provider you are getting an assymetrical service, so if you are getting a 4 meg service it is 4 megs DOWN to you; probably 1 Meg or less UP to the Internet, and these are line speed ratings, not actual performance: during peak you will be getting less in each direction…
Not saying cable is inappropriate for this use but you need to be careful to take this into account when you are calculating bandwidth requirements.