Most dual-mode phones can handle both VOIP and PSTN calls, although some are strictly cellular/VOIP.

VOIP phones that are PSTN capable are a great way to ease into VOIP, especially if you’re going to be keeping a PSTN line for backup or your security system. Some phones switch between modes automatically, while others require you to push a button or switch—it all depends on the model you purchase.

This ensures the least amount of variables in a specific network setup.

In addition, users should ensure that an “Error Correction Mode” or “ECM Mode” is disabled on their fax machines as this compounds problems and distortion regarding the compression, decompression, and transmission of data communications through a VoIP provider.

Also the “Baud Rate” should be lowered to no more than “9600″. When faxing the fax should be set to “Standard” instead of “Photo or Fine.”

In my experience faxing via voip is simply hit or miss. The problem exists when the 2 connecting fax machines, or in some cases fax modems cannot maintain a consistent handshake. The handshake occurs many times per second and is the method for which each device ensues that the other device is still listening. VOIP communications does not provide a consitently CLEAN connection, therfore during the handshaking noise may be introduced into the call causing either device to assume that the other has hung up. This noise come from the compressin being done to the data stream. Most providers operate on the codec, G.729 which uses lossy compression, which reduces the amount of bandwidth required, but can impact the call quality. Hence, a dropped call when faxing.
One method of attempting to fix this problem relies on slowing down the handshake in order allow for bad packets to simply fall off the call, and not interfere with the handshake in addition to changing the codec being used to compress the phone call to the G.711, employing no compression schemes, which requires more bandwidth but no call loss.

I have had limited sucess with vonage when faxing and no sucess with 3 other providers including sunrocket, lingo and voip.com. Your mileage may vary, i would suggest asking the voip carrier if they support a guaranteed fax solution.

If you have a Broadband or High Speed Internet Connection available, you can use your VOIP phone adapter while you travel. Your phone will work just as if it were at your home.

Take your phone number with you wherever you go. Plug your VOIP internet phone adapter into any available broadband connection and you can use your VOIP phone from anywhere in the world. Your phone will work exactly as if you were still at home. For instance, say you live in New York and take a trip to Helsinki. Plug your adapter into the hotel room’s broadband connection and the phone into your adapter. When people call your home number it will ring in Helsinki. Even better, their call will cost the same as always. The same goes for your outgoing calls.

DECT stands for Digital Enhanced Cordless Telecommunication

DECT is a European standard for cordless communication and data transfer. DECT phones are often dual-mode, able to switch between voipand the PSTN, for example. They also operate at 1.9 MHz, which Supports reduce performance lags on your home network due to interference. Although you don’t need one to use VOIP, DECT phones are specially designed to mesh with cellular and VOIP networks.

VOIP works just like a regular phone — all VOIP has done is replace the high priced phone lines with VOIP’s low cost, Internet Phone service. When you get a phone call, your phone will ring just like normal. You’ll hear a dial tone and make your phone calls just like you’ve always done. What’s changed is that you don’t pay an arm and a leg to use the phone company’s wires.

Making Domestic Calls

Dial the Area Code + Telephone Number (example: 1-555-123-4567)

1. This method is called 11 digit dialing.
   
2. You can dial any number in the US, Puerto Rico, and Canada using 11 digit dialing. (For Toll-Free numbers, you should use 11 digit dialing.)

Dial the Telephone Number (example: 123-4567)

1. This method is called 7 digit dialing.
   
2. You can call any number in your area code using 7 digit dialing.

Note: If you want to call a number in your same area code, you only need to dial the 7 digit number.

Making International Calls

There is one method available to make international phone calls.

1. Dial 011 + Country Code + Telephone Number

The same problems that you would have with FAXING will also apply to DVR and Home security systems. VOIP service providers use a compression method known as a codec. The G.729 codec which uses lossy compression, reduces the amount of bandwidth required, but will introduce noise to the call. With this in play your DVR or security system will have problems establishing a modem connection. One way to to fix this problem is to switch the hardware (ATA) to the G.711 codec which uses no compression schemes requiring more bandwidth but with no quality loss. Unfortunately when using more bandwidth you may then introduce other problems that exist when you get close to the max limitations of your internet services. One of which is throttling, this is when your service provider ‘pumps the brakes’ on your connection speed in order to pulse your usage and thus reduces the overhead on the line itself.

Your best bet is to check with the VOIP provider before you sign up for service.

You’re going to want a broadband connection that’s at least 90 kbps in both directions, upstream and downstream. Anything slower than this will result in very poor call quality; dialup service is not fast enough, and some satelite services do not have the up speed to support the phone service.

When considering an ISP provider, don’t forget to ask about average jitter, packet loss, and round-trip times for customers in your area. These can give even the fastest connection an unacceptable quality rating for VOIP. You can find out how VOIP Phone will sound and if it will work for you over at mySpeed.com.

** Satellite users please note **

Your outbound calling WILL NOT work.

Even though companies like Hughes Net claim to be Broadband. The UPSPEED is not fast enough to handle outbound voice, meaning all of your phone calls will result in choppy calling problems

If your phone calls sound choppy, broken, or you’re having other voice quality issues like delays, echo, or crackling/static noises, your network might not be optimized for VOIP.

When considering an ISP provider, don’t forget to ask about average jitter, packet loss, and round-trip times for customers in your area. These can give even the fastest connection an unacceptable quality rating for VOIP.

Before you do anything else, make sure you don’t have bandwidth hogs strangling your network. These include file sharing or other peer-to-peer applications, playing graphic-heavy online games, uploading large files with FTP programs, and sending email with big attachment sizes. Any time you’re using that bandwidth for something other than voice, you risk degrading the sound quality of your calls. Try pausing high-bandwidth activities and see if it solves your problem.

If you’ve dropped the bandwidth usage during calls but think there’s still room for improvement, you can:

1. Keep your VOIP internet phone adapter (the special router you got when you signed up for your VOIP service) well ventilated so it doesn’t overheat and make sure it’s positioned at least 3 feet away from any electronic device that might cause interference.
   
2. Take a moment and reboot your adapter, modem and computer. It may seem silly but this can solve a multitude of problems.
   
3. If you’re using multiple routers or other networking equipment, try plugging your VOIP adapter directly into the broadband modem. If this solves the sound issue, you might have a problem with one of your other pieces of equipment. Gradually add the equipment back into your setup until you’ve identified the one that’s causing the problem. Then you can contact the manufacturer for their troubleshooting recommendations.

First, check to see that you are not utilizing any “bandwidth hogs” on your network. Examples of these can be File Sharing (or P2P) applications, uploading large files with FTP programs, sending emails with very large attachments, or other types of activities where you may be using your bandwidth to send large files.

If you are running any of these programs, try pausing the activity and see if your phone quality returns to normal. If not, please try the following:

1. Make sure your Phone Adapter (router) is in a well ventilated area and has not overheated
   
2. If you are using multiple routers and other networking equipment, try plugging your Phone Adapter directly into the Internet modem. If this resolves your issue, you may have to troubleshoot your other devices.
   
3. Reboot your Phone Adapter (router)
   
4. If that fails, reboot your Phone Adapter (router), modem, and computer(s)