29 thoughts on “PSTN versus VoIP”

  1. “You can use only one phone plugged into the ATA, unlike PSTN where you can jack your handset in pretty much any phone outlet inside the house. (Of course, you can buy a wifi handset for about $100, but that’s not the same thing as what I am mentioning.)”

    This isn’t true. I have vonage and I have every phone jack in my house working. As long as you don’t have any phone service (meaning the jacks are “silent” when you plug into them), all you have to do is plug the phone line from the vonage box into the nearest jack. The dial tone should be accessible to any phone plugged into any other jack in the house, and they will work as if you had a traditional PSTN service (they will ring when called, can make calls, etc). It works perfectly.

  2. dan

    thanks for the clarification. i am having a tough time getting this to work. i was wondering if you could explain on what you mean by silent jacks? does this mean that there should be no pstn connectivity at all in the house?

    what do average people who normally don’t know much about phones do to make it work without being overwhelmed. appreciate the feedback.

  3. Don’t understand your assertion that VoIP restricts subscriber to one phone only. I have CallVantage connected to inside wiring and every handset in my house-corded and cordless-works fine. Does not require ANY technical expertise to do it.

  4. marvin

    i have been trying to make it work, and well it doesn’t. now i see dan and you are making it work, and i looked at the call vantage site, and have found a way to make it work. it did take some work. i am going to post an update in a little bit.

    i still think it needs some work… and might not be something mainstream users can find it easy to do.

  5. Om,
    By silent jacks I meant they were disconnected from outside phone service. I assumed that this just meant you had no phone service at all, but I guess it is possible to still have some outside service interference (especially in an apt or duplex). I was fortunate to have this work right from the moment I plugged the phone line from the vonage box into the wall jack. If everyone could have my experience, then anyone could do it, but if everyone has your experience then you are right, very few people could get it working.

    A better explanation here:

    I found a walk-thru on the web but it’s still complicated:

  6. I have used Vonage close to 2 years and by far and large it has been quite good. Had trouble with the Internet and phone connecton being “dumped” sometimes when trying to change browser pages. Chat with Vonage techs said problem was in Times Warner’s old Toshiba 1100U cable modems and that TW has an updated one. Called the latter and they readily gave me a new one which I easily installed. No more problems.
    With respect to house wiring I pay for both a basic as well as a FAX line and both are plugged into the house wiring and work fine with many phones.
    Also installed an inexpensive ($45) AC backup power supply and run the modem and ATA off of it giving me phone service even during the very few utility power failures we have in Austin.

    Recommend the service.

  7. Fellow blogger Jack wrote the seminal instructions on distributing VoIP throughout the home. If I recall correctly CV copied him wihout attribution. In any event, you should read the cautionary warning he gives about making sure that the telephone wire is disconnected at the NID. Interestingly, CIDCO has a product to take advantage of cell plan called MERGE. It comes with a gizmo that allows one to use the second line (if your home has it) for this purpose as you can see from the installation manual (pages 6 and 7).

  8. The main advantage of VoIP is that you can derive new features because the ATA is the Class 5 switch and that it gets message oriented signals. To see the possibilities take a look at the plans of PhoneGnome (and most of the features can be applied to PSTN line as well). All other differences are either temporary or secondary.

  9. Om, I have to agree with your assertion that POTS is a better product than Vonage. About a year ago I disconncected my POTS line and replaced it with Vonage. Everytime somebody would be using the computer to download large files it would affect the quality of my phone call. This was a frequent occurrence.

    Then there was a time when the power went out and I had to call 911 due to my fireplace burning way too heavy and I couldn’t dial 911. That moment took all confidence I had regarding Vonage away. I knew I could not rely on this service the way I could with POTS.

    My wife frequently complained that we could only have a single phone hooked up. I had to replace the phone connected to the ATA with a cordless phone so that we could use it throughout the house but the signal could not reach certain rooms properly. I followed the instructions on how to get it working on all phones and ended up got it worked eventually, but I would not expect the average user of phone service to attempt this.

    After the quality issues continued sporatically I eventually gave up and had POTS brought back in. I had to go fix the wiring and reconnect my house to the telephone company in order for it to work which was a real hassle.

    All in all I came to the realization that VoIP is not ready for primetime. I am much happier with POTS and am more than happy to pay a little bit of extra money per month to have a phone service I can trust.

    Jack Thompson

  10. VOIP is my telephony application of choice, but it is hard to make the case that you don’t need at least one plain old telephone service line in your house for the next couple of years.

    Many people dont realize it, but POTS runs on “network power” – you could lose power in your house and neighborhood and not lose your telephone service.

    It may be a good idea for home router vendors to routinely start bundling in basic UPS/battery backups with “power over ethernet” support that can be used by a few communication and home security devices that connect to that router.

    If my telephone, internet, and television are all going to ride on one wire or wireless channel – I would want that channel to be very robust. Otherwise, things will get very quiet when it fails.

  11. Om Dude==get with the 21st century !!! Voip HAS e911 IF you ride the Level3 Network,…Voip can WORK with multiple Jacks if you disconnect the wiring from outside into the house, and ALOT of voip providers now (packet8, SunRocket provide you with built in Router Cordless Multiple phones==========Vonage IS updating all its Points to include the Level3 e911 ! Yep, if the POWER goes out, you are screwed but Comcast has a built in Power Adapter included! POTS vs Voip??? Mercedes vs Toyota comes to mind, you want a Mercedes, you PAY for a Mercedes=====i will drive my half price Toyota into the Sunset at half the Price and TWICE the gas mileage!!! Anyway, I got a cell phone along with every SMART person in USA so if your power goes out, turn on your cell phone!!! Packet8 at $20 per month WITH e911 and Sunrocket giving you a voip phone is the DEAL!

  12. As an old school phone guy who now lives in this VOIP world there are a few things no one has copped to. Phones have a thing called a Ringer equivalence number. some may say RE1.2 for example. each device you add raises the ringer equivalence number for the line and may over tax the ability of the ATA to drive ring current to all the phones. Plus there is a possible issue of how many Miliamps of current are available to power the phones fo rvoice, msg waiting etc. RE rating is not such a big deal with the more electronic phones in use powered by 110VAC power bricks, but it is worth inspecting as a troubleshooting point of interest.

    Now these electronic phones have a way of usually working when the power is off, albeit on basically, you pick up the phone you hear dialtone and dial, no lights or ringers etc.

    I would posit an industry standard device for emergency backup. A solidstate low voltage router with built in ATA powered by a 9VDC battery in a cigarette box size case. All these pieces, opensource OS and software exist today. If you really wanted to be fancy it could include a rechargeable battery and a 110AV power brick. It only needs a commited service provider like Vonage to take the lead and just do it! It would be a great sales pitch and take away the demons of regulators and ILECS and stop the general whining for someone else to fix it for gazillions of dollars!

    It jogs the memory of an early internet company, they were driven by some russians writing really tight, memory efficient code who were good at what they did because RAM memory was so expensive back then and not so freely available, and broadband was not even a dream yet.

    I think the memory hog application laziness has raised it head in a different way now. Wastefull hardware and resource design practices.

  13. I’ve used Vonage quite happily for over 2 years now. When we first subscribed, the 911 issue was a big one for us, especially, as all readers point out, if power goes down, so does your VOIP phone service.

    Keep in mind that this was prior to the E911 being put into affect, but what we found was that the emergency dispatch center in our area (and other areas as well) have a number to call from cell phones or VOIP services.

    Here is San Francisco for example: http://www.sfgov.org/site/uploadedfiles/ecd/EmergencyCommunicationsDepartment/wireless.pdf

    It isn’t quite as convenient as having a hardline connection to 911, but it does provide a solution in the event of an emergency.

  14. I have had Vonage for my home phone system now for 4 years. Only difficulty I encountered was the bad Uniden hand set. Uniden replaced the bad set of wireless phones and i have been lovin’ the “V” savings @ $17.99/ month. Run one phone line out of a Linksys Broadand router and it it inturn provides service to the 5 phones scattered aroun our home. I also run a second line out the back of the router to a phone fax that sits aside my computer. We have our phone all set with “1” for speed dial to the Police. I find that a little easier to do than a “Is that 411 or 911?”

  15. As for #4 — you can plug the ATA port into your home wiring (back-feed so to speak) — and that will give you the ability to support all existing home phones — provided you don’t have more than several … should work fine …

    Let’s not forget a few facts:
    1. A number of “PSTN” customers are actually carried (24 — over HDSL) — the same local loop technology that is used for ADSL over which folks run voip.
    2. That neither HDSL nor the PSTN — nor any xDSL is perfectly reliable. And 5 nines is complete nonsense. I can personally attest to 89 days of no telephone service in 2003 (nice work Verizon).
    3. VoIP isn’t a network. Each piece has it’s own issues with reliability. More importantly a single network can carry multiple services. So if I have an issue with vonage, I can use Skype or other. Add vongage to skype in out and it’s still cheaper than pstn …
    4. A favorite — who cares — uses a cell phone for backup. You’d have a cell phone for backup for pstn anyhow.

    Just a few thoughts …

  16. Bright House / Time Warner connects their VoIP service to the existing phone lines, most of the MTAs they use have battery packs in them and they will not install the service without verifing that the e911 service will point to their home address.

  17. I can’t believe there is no mentiion of PHONEGNOME here! This is EXACTLY what we’ve been trying to tell people.

    Trying to make the Internet do everything the old POTS network does will take as long and cost as much as the POTS network, and is a poor use of a good thing. Making the POTS network do what the Internet does is equally silly.

    PhoneGnome uses the POTS network for what it’s good for (and what is hard/expensive and pointless to do to the Internet) and uses the Internet for what it is good for (and what is expensive and pointless to do to the POTS network). — and it’s a solution HERE AND NOW , rather than in 15 years if people were actually to do to the Internet what the petition says to do.

  18. Mr. Blog,

    I think you are right to point out that I skipped your product. Sorry about that. but if you look at the piece, it was a straight up comparison of what is pstn and what is voip service from vonage etc.

  19. VoIP has many advantages over PSTN too :-
    – You can carry a voip phone alongwith you to andaman and nicobar island and still use it provided you have a broadband connection.
    – You don’t require a dedicated Copper wire for your conversation.
    – VoIP is dead cheap.

    Register now to discuss voip related topics at http://www.voip-traffic.com/terms.asp with experts. Its free and easy.

  20. Today I ordered Vonage service for unlimited 2499 tax=$27.72 – free adapter/router combo, first 30 days free and “no activation fee a 29.99 value” (mktg gimmick, i know) shipping & handling $14.99 (rip off) to start service is all I paid (3 day shipping.)

    I am currently paying $22 or so for basic landline from Qwest and 49.99 for Tmobile 2-phone family service.

    Basically then, I am moving the $22 into VoIP. I have used Vonage at several places at my friends and it works pretty good.

    One important feature that Vonage has that was’nt mentioned here – there is a feature called Network Availability # . Looks like vionage pings your end and if not able to connect reroutes calls to your other numbers.


    ————-text here————-
    Set Your Network Availability Number

    And Never Miss a Call
    Don’t miss any calls even if your Internet connection goes down

    Vonage protects you. Now you don’t have to be inconvenienced if your Internet connection fails. Your calls will be automatically forwarded to the phone number of your choice in the event your Internet connection is disrupted or your telephone adapter is disconnected. If Call Forwarding is enabled, all of your calls will be forwarded using your Call Forwarding settings. If you don’t have Call Forwarding enabled, we will forward all calls to the number you register as your Network Availability Number.

    Your Network Availability Number is similar to Call Forwarding, except that it’s activated only when your Internet connection is disrupted or your telephone adapter is disconnected. Once activated, calls to your Vonage phone number will forward to the number you choose until your Internet connection is restored.

    Setup Is Painless

    1. Login to your Vonage Web Account

      Click on the “Features” tab from your Dashboard

    It doesn’t cost extra charges to use our handy Network Availability Number feature. For Unlimited Plan customers, calls are included as part of your monthly service. Rated plan customers are included as well unless if the forwarded call is not within their monthly allotted minutes.

    This feature is included in your Vonage monthly calling plan as an added protection against missed calls.

    so for power outage or internet outage, my calls will still come into my mobile phone either using call forwarding or the default network availability feature.

    Will be getting the package about Friday and will know what the VoIP revolution” is first hand.


  21. what are you all carrying on about im in australia btw just incase what i say here doesnt completly make sence with different brand names and all

    in australia if your not lucky enough to live in an area where you can get cable you have to have ADSL and with our ADSL you must have a POTS line with a pots phone number as our telco that owns the lines will not allow naked DSL because they know they would loose to much to voip

    so i have my pots line connected to my ATA wich also supplies VOIP from a company called engin

    my ATA then plugs into my router and the Ethernet Network that is already routed around my house upstairs and down either by ethernet with power over ethernet or by wireless wich reconects to wired ethernet with POE upstairs

    I then have 2 desk IP phones upstairs and a cordless phone with an ATA on it
    Downstairs i have 1 IP deskphone and 1 cordless phone with ATA

    all these phones are connected by a soft PBX system and each phone has a seperate extension each phone can recieve a phone call of the POTS phone number when people call in and it calls out onto the Voip network when we ring sum1

    if the power goes out my engin ATA drops back to the POTS line automaticaly in wich case i can call using the pots line but since i have Power over ethernet with a UPS (wich i rigged up using a couple of old car batteries) it is conected to the network and all the phones that are on the network and the computer that runs the PBX system so that i can use any phone in the house on the Voip network for up to 6 hours with no power

    and with your 911 calls wich in australia are 000 calls with the pbx system to get an outside line you have to dial “1”to get out on a voip line or you have to dial “0” to get out on the Pots line so your just dial 0000 and you get our emergency 000 number dialed on the pots network so there is no need to worry about anything

    i sugest you all take the time to set this system up

    the other thing you can do is set up the voip box directly to the pstn box out side your house and that way all incoming calls on your pots number go to all phones in the house and it wires your voip so that it goes to any phone socket in the house a good link to see how to do this is


    I hope that some of you find this post interesting

  22. Jeff and Tom your comments are off base regarding the VOIP services. This is very typical when a consumer like yourself thinks he knows what he’s talking about. First of all you don’t have all the facts second of all your comments are very general in regards to location and types of services. I don’t know where you live but it may be hard for you believe all POTS (plane ole telephone services) lines are not the same. You obviously live in an area where the phone company has placed its cable in the ground in recent years and by recent I mean in the past 10 to 12 years. I have been on both sides of the fence regarding telephone and cable. I was a cable splicer and project manager for Sprint for many years I have also networked and built many long hal fiber networks across the country. I have been in every aspect of the business conceringing design, construction and deployment for both cable and telephony services. With out a doubt I can tell you 80% of the R&D money for VOICE DATA and VIDEO services are headed toward the big pipe CABLE. It is a matter of bandwidth, quality of service and end user cost. The local loop service or the 800 pound gorilla as I like to refer to them as is not adgile enough to fit todays consumers needs. The fact of the matter is VOIP is reliable after all VOIP is how 90% of all longdistance calls are networked today and have been for many years. Did you think the was 15 million copper pairs laying on the ocean floor each carrying 1 phone conversation. What gets my goat is you are just one example of thousands spreading bad info about something you don’t know about and on top of that you get people riled up to follow you who look to you for good info who don’t know half of what you think you know.

    1.Voip installs very easy to all jacks in the house, can mom do it? NO but mom did’nt install the phone in the first place did she a telephone guy did.

    2.VOIP is very reliable, it is as reliable as your cable provider if you have a good provider you have good internet and digital phone service.

    3.E911 is there and works great, all VOIP providers must carry it.

    Well over 20,000 people a day take advantage of a VOIP service and I’m here to tell you all of them are not taking it just to save $10 bucks.


  23. I have been using VoIP, in one form or another, for residential phone service for more than 8 years. I currently have 3 voice VoIP lines and 1 Fax VoIP line.

    However, I still have my good old POTS service from Bell and I don’t intend to give it up for the foreseeable future. Here’s why:


    Unless the service provider owns the network path end-to-end, they are unable to guarantee voice quality. The service is at the mercy of the conditions of the network between the end-device and their network. Despite this, in most cases it works great. But, if there are congestion or reliability issues anywhere along the path, you and the service provider may be completely powerless with respect to rectifying the issue. This happened to me a few years ago when my service provider began experiencing network congestion. My VoIP service became unusable due to excessive delay and jitter. Luckily I moved, and for the past two years the voice quality of my VoIP service has been great. But that could change at any time. Obviously the cable companies have an advantage here but that advantage is restricted to the subscribers that are on-net.


    I am very confident that Bell Canada will still be in business a year from now. I’m also very comfortable with their ability to maintain consistent quality. In a year, my VoIP provider might be bankrupt. In fact, as I have stated previously, I’m convinced that a standalone best-effort VoIP service is not a sustainable business model. Vonage must change their business model or, I’m convinced, they will not survive. While the quality of my VoIP service has been, for the most part acceptable, I have experienced outages and messaging issues that are related to the VoIP provider’s core infrastructure. I lack confidence in their operations and their ability to scale; especially if financial pressures results in them sacrificing investment in operations in favour of marketing for example.


    Yes, it’s true that most VoIP providers have E911 capabilities. However, in many instances, unlike your POTS service, your call does not terminate directly in the E911 PSAP. Instead, it is directed to a call centre first, which in my view, could potentially compromise the efficacy of the response. In addition, as others have pointed out, unless your ATA has, or is plugged into, a backup power supply, your VoIP service will be non-functional in a power outage. Even, with ATA backup power, a power interruption might bring down the network through which your VoIP service is delivered. Sure, most cable companies do have UPS to protect their trunk and distribution amplifiers but the capacity may be very limited which means that an extended and widespread outage will almost certainly result in your VoIP service going down. In addition, the reliability of the backup power is dependent on diligent maintenance, which is a non-trivial and expensive challenge. My Bell Canada phone service, I am confident, would continue to work even if a power outage lasted for weeks.

    I am not bashing VoIP. I am passionate about the industry and the many advances that have been, and will continue to be enabled by VoIP. I use VoIP services because I get great features and services that are not available through any other source. For residential voice services, I am aware of the potential VoIP pitfalls and I accept the risk. So choosing VoIP or not, exclusively or not, should be based on knowledge of the facts and the risks.

  24. On,

    Good post…but i discord of two affirmations:

    *** You sacrifice quality.

    Do you dont sacrifice quality with VoIP. your lan network is preparated to VoIP? Your internet link is preparated to VoIP? Latency, packet loss… say VoIP SACRIFICE QUALITY is LEGEND! (I can prove this)

    *** You lose 911 service and most importantly…
    The integration with PSTN network to VoIP depend of a end point PSTN! Your end point PSTN! Your end point PSTN support special numbers? Too a legend!

    (excuse-me for my english)

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