I'm looking to share a single-line phone automatically across two lines (a VoIP line and a POTS line), and am looking for devices with this support.
The most uncomfortable thing I find about VoIP presently is the limitation of 911 service
.You cannot simply dial and hang up, you must wait to leave your location (in contrast to landline service which requires only the call to connect). And of course if the VoIP provider, the internet, or power are interrupted, 911 on VoIP will be unavailable. With a small kid, guests in the house while I'm away, etc., I feel more comfortable with a phone system that doesn't carry caveats and works as one has come to expect when one has come to expect it to work. Consequently, I've kept my landline, stripped of features, for the express purpose of dialing 911. I'm now looking for a solution which will bind my landline and my VoIP line into one single line phone. I've got only single line phones in my house now, and replacing them with two line phones would eliminate the cost benefits of switching to VoIP in the first place. My second guiding principle therefore is to not outlay more money than I'm saving. Here's my ideal setup: I'd connect both incoming lines to some box which also has a single output to a telephone. When a call comes in to either line, the phone will ring, and on pickup it'll be attached to the active line while the other line is simultaneously placed off hook to generate a busy signal should someone call on that other line. The two incoming lines would operate completely symmetrically. When placing outgoing calls, lifting the receiver should by default attach to the land line (again busying the other VoIP line). If however, I dial a prefix (typically something line #0), the outgoing call would swap to VoIP and busy the landline. Power outages should affect only the ability to select the VoIP line, although it's permitted that the "busy the other line" function might be unavailable; in other words, even during a power failure, I should get a straight connection from my phone to landline for incoming and outgoing calls. These features of the solution would permit me to make calls on VoIP with only a small change in behavior (adding the prefix), and importantly permit use of the landline with absolutely no change in behavior, satisfying my initial goal.
I've found a few of these boxes, but none of them are perfect. Here's what my research has uncovered:
interesting choice. On the plus side, it approximates what I want somewhat closely, and could be quite cheap (
Thanks, Martin. That's a great suggestion for folks who are looking to start from scratch and have the option to select their router. In my case, though, I've already got a VoIP router - a Linksys PAP2, which has only two outbound FXS ports and of course the ethernet port; no support for incoming POTS. It was free, so I can't complain about the lack of this specific feature I want.
What I'm looking for is something that I can attach "after" the VoIP router to automatically switch between the FXS line and a POTS line. Of course, the source nature of the lines doesn't matter much - I could equally well be switching between two POTS lines.
BTW, I forgot to clearly mention in the original post: manually operated devices won't work for me since the idea is to centrally locate this to serve my whole house. Since the device will be inaccessible, it's got to be automatic.
I would have thought that this application would be very common, and am surprised that it's been so hard to find solutions in scouring the web. Perhaps I'm one of very few out there who are looking to bind two phone lines into a single device in this manner,
I realize after reading your posts, that you have a locked device you want to do this with. I am only aware of a device that does this with a POTS line and an open BYOD provider, the Sipura 3000. Includes free service too. But, it appears you've already done your research and came up with some devices that might fit the bill. AAMOF, this might not even be what you are looking for at all!
The SPA-3000 features VoIP adapter functionality found in Sipura's wildly successful SPA-2000 and SPA-1000, with the additional benefit of an integral connection for legacy telephone network "hop-on, hop-off" applications.
SPA-3000 users will be able to leverage their broadband phone service connections more than ever by automatically routing local calls from cell phones and land lines to a VoIP service provider and vice versa.
A typical user calling from a land line or mobile phone can reduce - and even eliminate - international and long distance telephone charges by first calling their SPA-3000 via a local phone number or by using a telephone connected directly to the unit. The advanced authentication and call routing intelligence programmed into the SPA-3000 connects the caller via the Internet to the far end destination with security and ease.
At the far end, calls can be answered immediately or further processed as a local call to any legacy land line or mobile phone allowed by the SPA-3000 dial plan.
The SPA-3000 may also be used for life line applications. For example, depending on the service provider?s set-up, callers who dial 911 can be automatically routed via the IP or legacy telephone network.
If power is lost to the unit or the VoIP service is down, calls will still be sent to a traditional carrier via the FXO interface. Sipura is currently working with several service providers to further define requirements for life line support in products such as the SPA-3000.
In addition to the hundreds of programmable features available with VoIP phone adapter functionality, the SPA-3000 provides specific features to allow calls to be routed to and from the FXO interface. Some of the features available on the SPA-3000 include:
Multiple, Configurable Dial Plans Activated for Individual or Groups of Users; Single and Dual Stage Dialing; FXO / VoIP Line Sharing.
Sipura SPA-3000s purchased from Voxilla include the following:
One free month, with all activation fees waived, of any Broadvoice's unlimited plan, including "Unlimited World Plus";
Up to 100 free calling minutes through iConnectHere;
One free month, with activation fee waived, of VoicePulse unlimited US-48 calling (US residents only, see Terms and Conditions );
Access to Voxilla's Sipura user group forums for technical support. Quantity Discounts:
I'm not interested in buying two line phones to replace the single line ones I have (5 of them) in the house since that would cost more than I'm saving on switching to VoIP.
Placing pairs of single line phones around the house is what I'm presently doing, but it's inconvenient and inelegant. Also, it doesn't solve my problem of providing 911 emergency service "without thinking". With separate phones as you suggest, there's a 50% probability of picking up the wrong phone to dial 911.
Has anyone used any of the hardware devices I mentioned in this thread's original message?
If a 911 call is your concern, then a VoIP router with a fallback POTS line will not help you much: what if someone broke into your house, but the power is still ON? The call is still going to go through the VoIP line. It looks like what you need is a small PBX that can support least cost routing, which you can program in such way that if "911" is dialed, it hits POTS trunk, no matter what the status of the power is.
I can't really come up with a suggestion on equipment that is capable of least cost routing, but is affordable enough for a residential install though. Maybe a used Magix?
Thanks for the reply, Marc. In fact, I've seen you've often taken the opportunity to promote this device you sell. It appears that outgoing call paths are manually selected, however, which doesn't suit my purposes at all as you'll see from the original and follow-up posts. jeff
Thanks for the thoughtful response, Dmitri. My initial post was probably fairly complicated and it may have been difficult to see how my request handled the situation you decribe. By default, picking up the phone will always give you the POTS line, unless you specifically dial the VoIP prefix to select that outgoing line. When power is ON, in your scenario, the call would therefore go out through POTS, not VoIP. When power is off, same thing, although you obviously wouldn't have the option of selecting VoIP because neither the VoIP router, nor this magic box I'm envisioning would be active.
The Magix suggestion is a good one, but sounds pricey and complicated. I was really hoping for a simple, small standalone box (take a look at the skutch device whose link I referenced in the original post - something small like that). I could have sworn that Radio Shack sold these a decade or so ago, but can no longer find reference to it.
I'm new to this game, I got broadband just before Christmas and decided to get a Zoom X5V router. I'm not sure what you mean by "a VoIP line" so this may not be of interest. It takes an adsl connection and a POTS line and provides a single phone output. This is from the datasheet:
"The Local Phone port of the Model 5565 includes an intelligent relay that allows a single phone to place and receive both VoIP calls and calls over the Public Switched Telephone Network (PSTN). PSTN Fail-Over allows the X5v to automatically route calls over the dial-up phone network when power is lost. PSTN support also allows emergency dialing using services like 911 or 112 calling."
".. the Model 5565 lets you dial the call normally, and your call goes out through your local phone line to the traditional "public switched telephone network" or PSTN. When you want the call to go out over the Internet, you dial a # before dialing the person's phone number."
Incoming calls on either line will ring the phone. That sounds like what you are asking for. The full datasheet is here:
It has a REN of 5 and I'm running 2 fixed phones, a cordless and a loud bell from it.
I haven't checked how it works here in the UK as we use 999 instead of 911 and I'm just getting to grips with it. The downsides I've found so far are no uPnP support and possibly a limited number of peering agreements with other suppliers.
an intelligent relay that allows a single phone to place and receive both VoIP calls and calls over the Public Switched Telephone Network (PSTN). PSTN Fail-Over allows the X5v to automatically route calls over the dial-up phone network when power is lost. PSTN support also allows emergency dialing using services like 911 or 112 calling."
over the Internet, you dial a # before dialing the person's phone number."
That's exactly the same arrangement I mentioned earlier available on Draytek Vigor Voip routers models 2500V, 2600V (two VoIP ports), 2600GV (+wireless).
I don't think Zoom has wireless routers. Regards, Martin
The clt cannot know which line you want a priori' in most cases the voip crowd would like the unit to default to "line 1" which is the voip gateway... in the case of local mayhem the caller would like the pstn as the
911 folks can instantly trace the local number to an address and react...
currently the clt, will pick the outbound based upon the last line used, unless you push the little button and select the line you like. however in all cases the two lines are automatically 'joined" to your favorite single Telco devices.
I use the devices on two pstn lines as I like the sound quality of my older ma bell single line phone , yet need two line access often. for the other locations two line phones have an unusually high premium associated. hence clt was born. I designed this beast before voip was popular. fortunately extra jacks were added allowing for uses (including voip) that were not contemplated yet today are the main basis for clt sales.
At the time I had been freshly "ripped off" from vc firm that killed my prior endeavor and was anxious to "do it again" so I am a serial entrepreneur... I was thinking of using a "No vc dollars" used logo... but did not ....
Sorry, I must have missed that, I didn't intend to clutter the group.
No, but it's a lot cheaper :-)
I actually phoned a local Draytek supplier I've used before and asked if they could give me a good reason to buy their product instead of the Zoom. They hadn't heard of it and when we went through the specs, the only advatages were QoS and uPnP. The price was 50% higher so I couldn't really justify it.
I thought about that but I'm not a gamer or use the net for music so I don't do many big downloads. My total usage is around 600Mb/month, mostly mail and newsgroups, though I've been downloading a lot of softphones lately ;-)
If I find it's a problem, I'll upgrade to a Draytek but I guess it'll be many months until the VoIP traffic justifies it, I have to get my friends onto it first.