[Asterisk-Users] Vonage, PSTN, 911, and hardware question

[Greg Hill]

On Sat, 9 Oct 2004, Rajeev Sharma wrote:

> And, back to this question:
>
> 2. Phone availibility during a power outage is a big concern. I'm planning on keeping my regular
> PSTN line around for emergencies and 911 dialing (so that 911 calls actually go to the 911 center,
> along with my address). Is there an easy way for all the phone jacks in my house to automatically be
> switched to the PSTN line if my broadband goes out? I'm also planning on hacking together a powered
> switch so that when the computer's power supply goes down, the line gets switched fully to the PSTN
> line, but I'm hoping somebody can give me a better solution.
>
> Anybody have any suggestions about this?

honestly... that really is the way it's done. Many PBXs have a two-pole
relay for each incoming phone line. When the PBX is powered up and
operating normally, the relay is pulled in. When the PBX loses power or is
in some other non-operational state, the relay is released so that the
line is switched over to the backup phone.

It might seem more elegant to do something with transistors or other
components, but when you consider simplicity, reliability, and ease of
implementation, it's hard to beat an old-fashioned relay.

I haven't heard any confirmations, but I imagine that the same technique
is used in devices like the sipura 3000 which switch their output to the
POTS input line automatically during a power failure.

Greg


> Steve Maroney wrote:
> >>Thanks for the reply. Well, unfortunately, 911 and power outage service is a problem for me.
> >>However, ignoring that, there are still three main questions that I definitely need answered:
> >>
> >>1. Calls in through PSTN line and out through VOIP (Vonage) line- will this work?
> >>2. Would I still have to use the Vonage ATA and plug the phone-line out into my * box, or do I just
> >>plug an ethernet cable straight into the * box?
> >>3. I'm not going to use a VOIP-only phone, so I would like to use the phone jacks in my house. I was
> >>going to plug in a phone line out of the * box and plug it into one plug, so the phones would work
> >>in parallel (that's what everybody does I think). Does this mean I would need three X100P cards? (I
> >>would buy something like the Wildcard TE410P, but $1495 is a little steep if you ask me. ;))
> >
> >
> > 1. Yes.
> > 2. Possible both ways.
> > 3. The X100P is a single FXO port card. The TE410P is a 4 port T1 card
> > which isn't what you want unless you have a T1 circuit. Maybe you want the
> > TDM400P with 4 fxo moudles. Those are only 337.00 USD.
> >
> >
> >>dean collins wrote:
> >>
> >>>Rajeev,
> >>>1. I have a packet 8 service connected to my X100P card, works fine.
> >>>2. as for power outages, buy a ups or lets face it that's what mobiles
> >>>are for. As for 911 I think this is just crap, when was the last time
> >>>you called 911?
> >>>3. Yes your hardware is sufficient
> >>>
> >>>Best way to get started is to use one of the how to guides and grow from
> >>>there.
> >>>
> >>>Cheers,
> >>>Dean
> >>>
> >>>
> >>>-----Original Message-----
> >>>From: asterisk-users-bounces at lists.digium.com
> >>>[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Rajeev
> >>>Sharma
> >>>Sent: Saturday, October 09, 2004 10:20 AM
> >>>To: asterisk-users at lists.digium.com
> >>>Subject: [Asterisk-Users] Vonage, PSTN, 911, and hardware question
> >>>
> >>>Hi. I've never deployed a Asterisk system before, so go easy on me. :)
> >>>I'd really appreciate if you
> >>>answered these questions:
> >>>
> >>>1. Is it possible to use Asterisk with Vonage VOIP service? (I'm talking
> >>>about the "Premium
> >>>Unlimited" plan.) I think I've seen something about plugging the phone
> >>>line from the ATA into a
> >>>Digium card, but I'm guessing it would be a lot easier to just bypass
> >>>the ATA.
> >>>
> >>>2. Phone availibility during a power outage is a big concern. I'm
> >>>planning on keeping my regular
> >>>PSTN line around for emergencies and 911 dialing (so that 911 calls
> >>>actually go to the 911 center,
> >>>along with my address). Is there an easy way for all the phone jacks in
> >>>my house to automatically be
> >>>switched to the PSTN line if my broadband goes out? I'm also planning on
> >>>hacking together a powered
> >>>switch so that when the computer's power supply goes down, the line gets
> >>>switched fully to the PSTN
> >>>line, but I'm hoping somebody can give me a better solution.
> >>>
> >>>3. I'm assuming it would be (relatively) easy to configure Asterisk to
> >>>dial out through VOIP and
> >>>answer through PSTN. Is this correct?
> >>>
> >>>4. Hardware. I'm planning on using a Pentium III 500Mhz computer,
> >>>running Debian Linux (probably
> >>>Woody, maybe Sarge if it's stable by the time I build this system).
> >>>Assuming I have 1 PSTN line and
> >>>up to 3 VOIP lines, would this be enough? Also, which phone card would
> >>>you recomend? I'm kind of
> >>>confused about which card to buy (I've only looked at the Digium site as
> >>>of now), and they all seem
> >>>extremely expensive. (I was expecting to spend ~$50, but oh well.)
> >>>
> >>>Anyway, that's all I can think of now. I'm sure I'll think of more
> >>>questions later. Thanks in advance!
> >>>
> >>>-Rajeev