[asterisk-users] VOIP Bandwidth questions

[Erick Perez]

I forgot to tell that my "rant" is about a centrally handled servers,
with no re-invite and no "spider-like" interconnects with smaller,
geographically located switches.

On 11/2/06, Erick Perez <eaperezh at gmail.com> wrote:
> This one will surely heat up.
>
> Usually the telcos have to calculate the subscribers vs telco capacity.
> I use simple figures, so extrapolate this to millions of customers,
> millions of lines, peak amount of calls at any given time of the day
> and of course houndreds,thousands of millions of dollars in equipment.
>
> For example:
> Telco A has 100 subscribers to his phone service in a city (home and
> business), so he needs to ask himself
> a- Will the telco buy a switch that can handle 100 calls
> simultaneously? So he can provide service to his subscribers 100% of
> the time at any time of the day even during riots,panic,flood,etc?
> b- Or will the telco go for a balance and guess that at the peak time
> of the day he will have 75 simultaneous call, so he goes out and buy a
> switch that handles 75-80 calls at the same time?
> c- how many trunks will the Telco have to talk to other telcos? So
> telco in City A can communicate with Telco in city B (or even in the
> same city)?
>
> International voice providers suffer from this kind of problem. Some
> sell plastic cards with a local phone number and a pin so you call
> them to call to other cities/countries but that cheap voice provider
> has, let's say, ten thousand long distance lines and ten thousand
> local phone numbers, but they sell 100k plastic cards a month with a
> peak usage 3 times every ten days of 12thousand lines? obviously 2
> thousand callers wont get connected (only 3 times every ten days in a
> specific time range) but the other 7 days the peak usage is 10thousand
> calls?
> Every ten days the provider try to connect 106k calls but fail to
> connect 6k calls, that's 6% failure rate every ten days (100% in a 7
> days period and 98% in those 3 days). Can you live with that failure
> ratio? that's up to you.
>
> I don't work for a Telco, but a Telco may apply the dialup-internet
> rule (and they live happy with it) for 30subscribers-to-1line home
> users and 10(or 5)subscribers-to-1line for business. (correct me if
> I'm wrong please it will be nice to know real figures).
>
> So apply the same rule to you VoIP hosting.
> -What codec will you use? let say g711 and let's say it uses
> 100kilobits per leg.
> -How many subscribers will you have in a 6 month period? 500
> -So to provide all of them with service you will need 48Megabits of
> bandwith all the time just to connect to your Telco equipments.
> - But you decide that you analyzed the usage patterns of your service
> and you will have only 125 subscribers calling other 125 subscribers
> (this is called On-Net) at peak time every day at 6pm (rush hour). So,
> go out and buy 24mbits of bandwidth only.
> - But you suddenly have the option to hire "burst IP service" where
> your IP carrier can provide you with more bandwidth if your usage
> starts to rise in any given time of the day. So you calculate again
> that your minimum constant usage at any time of the day is 40 users
> On-Net, so go out and buy 5mbits (for a total of 50 calls) of
> bandwidth with burst IP enabled from 6pm to 8pm of 48mbits (or
> 24mbits).
> This scenario is only subscriber----your_company----subscriber.
> you also need to calculate subscriber--your_company----other_telcos
>
> And the last but most important question is: how much money do you
> have to burn on this?
> 100% Uptime full-service, Top Carrier Class performance (and even they
> get busy sometimes)?
> or almost perfect service with the once-in-awhile glitch of "we're
> sorry all circuits are busy, please try again".
>
>
>
> On 11/2/06, mail-lists <mail-lists at peachnet.com> wrote:
> > Hello everyone,
> >
> > This probably isn't the correct place to ask this but I thought I'd
> > check here first.
> >
> > We're getting ready to roll out a hosted pbx solution on  a very limited
> > trial basis (some company employees are going to get voip service at
> > home). Our main issue is of course bandwidth. We have enough bandwidth
> > (spread across two locations) to accommodate the few employees (around
> > 10) for the near future but we're worried about how this is going to
> > scale. Obviously at some point we'll need to consider 'real' bandwidth.
> >
> > My question is this: How do huge voip companies like vonage handle
> > bandwidth. I'm pretty sure that they have to have sufficient bandwidth
> > available for X numbers of simultaneous calls, in other words ALL VOIP
> > traffic runs through their servers, right? My boss is of the mind that
> > there is no way that this is a viable business model and his insistence
> > has me doubting myself.
> >
> > So, to clarify - Vonage has to have the necessary bandwidth to handle
> > whatever amount of simultaneous calls. I can imagine that one vonage
> > user calling another vonage user would use some sort of sip re-invite
> > and perhaps even calls to other huge providers (packet8) are direct
> > client to client. (Last time I read about this it seems that even calls
> > to other large voip providers go through the PSTN  though). Barring voip
> > to voip calls, everything must run through their bandwidth right?
> >
> > If I'm right on this, I guess we need to come up with some sort of
> > viable business model to do sell our own service. I want to concentrate
> > on smb clients to whom we can then provide an asterisk box which would
> > leave our bandwidth free, but my boss isn't particularly keen on this
> > route.
> >
> >
> > Anyways,
> >
> > Thanks for any insight and advice on this question, sorry if I'm asking
> > this in the wrong place
> >
> >
> > Thanks,
> >
> > Steve
> > _______________________________________________
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> >
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>
>
> --
> ------------------------------------------------------------
> Erick Perez
> Panama Sistemas
> Integradores de Telefonia IP y Soluciones Para Centros de Datos
> Panama, Republica de Panama
> Cel Panama. +(507) 6694-4780
> ------------------------------------------------------------
>


-- 
------------------------------------------------------------
Erick Perez
Panama Sistemas
Integradores de Telefonia IP y Soluciones Para Centros de Datos
Panama, Republica de Panama
Cel Panama. +(507) 6694-4780
------------------------------------------------------------