Understanding FoIP

Home Improvement

Okidata 5980 IP-enabled fax machine
Photo courtesy HowStuffWorks Shopper

Fax over Internet Protocol (FoIP), or IP faxing, is a technology that has been around for many years. If you have ever sent a fax from a computer, you have already used a form of FoIP. Initially, IP faxing did not provide the same experience as a traditional fax session, with the familiar beeps and confirmations that let you know you are connected to the recipient’s machine, but the latest generation of FoIP systems combines the benefits of traditional faxing with the cost savings of internet transmission methods.

In this article, we will learn about the basics of IP faxing, explore a typical FoIP setup, and discover the challenges that hinder seamless faxing over the internet.

Understanding the Basics

FoIP, also known as IP faxing, is a technique used to send faxes over the internet. Similar to VoIP (Voice over Internet Protocol), FoIP changes the transmission medium of faxing by sending data between sending and receiving devices through a packet-switched network (typically the internet), rather than using the long-distance phone lines of the circuit-switched telephone network. This results in lower transmission costs and can be a more efficient setup for businesses that have internet bandwidth access.

The “IP” in FoIP stands for Internet Protocol, which is a set of standards and steps used to transmit data over the internet to the correct destination address. Instead of transmitting fax information as analog signals over phone lines, FoIP transmits it as “IP packets” over the internet. An IP packet is a data chunk organized in a way that enables internet routers and destination machines to decode and understand the data inside it.

Using FoIP does not require purchasing a new fax machine. Traditional (3G) fax machines can transfer data over the internet using gateways between phone lines and the internet. For those who want to eliminate phone lines entirely, an IP fax machine that connects directly to the internet can be used. When transmitting a fax between two IP fax machines, the transmission cost is the same as for email, and it’s faster because transmission relies entirely on broadband channels.

The FoIP setup is similar to the VoIP setup, and IP faxes can even be sent using a VoIP server. However, since faxing requires more bandwidth than a voice call, a VoIP server doesn’t automatically work for transmitting faxes. This typically requires some modifications, which can be made by installing software. Some companies also make servers that are optimized for both VoIP and FoIP applications.

There are many ways to implement FoIP. In the next section, we’ll explore a simple IP faxing system and some of the options available.

Using FoIP: Your Options

There are several ways to set up a FoIP system. One option is to buy software that turns your PC into an IP fax machine. Another option is to buy software that adds faxing capabilities to your current VoIP server. You can also purchase an FoIP/VoIP server or an IP fax machine. Alternatively, you can subscribe to an IP fax service to use with your G3 fax machine, much like using VoIP with your home telephone.

When it comes to FoIP, there are two primary transmission methods: store-and-forward and real-time IP faxing. The former involves transferring fax information via email attachments from one fax server to another using a lower-level Internet protocol like SMTP. In contrast, the latter involves transferring fax information in real-time as IP data packets between fax servers using a high-level Internet Protocol like TCP or UDP. Real-time IP faxing feels just like a traditional phone-line fax, allowing fax machines to exchange information at each step of the way.

There are various configurations for real-time IP faxing systems, but all involve the use of IP addresses. When transmitting a fax between two IP fax machines, the phone number is converted to the corresponding IP address for the receiving machine. When sending a fax from an IP fax machine to a G3 fax machine, the IP fax machine generates the IP address of the fax server closest to the receiving machine using the destination phone number. It’s important to use a local fax server to avoid expensive long-distance lines during transmission.

In summary, FoIP systems can be set up in various ways using different hardware and software options. Real-time IP faxing offers a traditional faxing experience and involves the use of IP addresses for transmission.

During a real-time IP fax session, all of the exchanges that occur in a traditional fax session are included. However, there is a lot more going on behind the scenes to enable the conversion between phone-line faxing, which uses the T.30 protocol, and real-time IP faxing, which uses the T.38 protocol. In the following section, we will examine this process in more detail.

FoIP Protocols

To better understand what occurs during an IP fax session, it is helpful to examine the various phases of a fax. When a document is inserted into a fax machine and a phone number is dialed, a signal is sent over the phone lines to initiate the fax session. The receiving machine responds with a series of tones to confirm the connection, and the two machines exchange control signals to determine their capabilities.

It is important to note that fax machines are digital, while phone lines are analog. Therefore, the T.30 protocol is used to encode digital information into analog signals on the sending end and decode analog signals back into digital information on the receiving end.

Once the machines have established each other’s capabilities, the sending machine produces a series of bits that represent the black and white areas of the page in digital form. These bits are then converted into analog signals for transmission over the phone line. The receiving machine decodes the page data back into digital form and prints the page based on the instructions provided by those bits.

Timing is crucial during a fax session, and phone lines provide constant timing for each phase of the session. During a real-time fax session over the Internet, the same phases and confirmations occur. FoIP uses the same method of compressing and interpreting image data as G3, but it uses the T.38 protocol for transmitting the data. T.38 converts traditional fax data into an Internet-friendly format by packaging T.30 fax signals and data as IP packets on the sending end and turning those IP packets back into T.30 signals and data on the receiving end. This conversion process occurs during each phase of an FoIP session between two G3 fax machines.

The process of faxing over the internet involves a significant amount of data conversion. To increase efficiency, it would be better to replace the old T.30 protocol with a digital, end-to-end packet-based protocol. However, T.30 is the only language that every fax machine can understand, so it cannot be discarded. The internet’s timing instability poses a challenge to successful real-time sessions. In the following section, we will discuss the obstacles to a seamless IP faxing session.

There are various operating issues that affect the successful transmission of a fax over the internet. Protocol conversion is one of them. Since there are millions of fax machines that only understand T.30, FoIP must convert T.30 data into T.38 data for transmission and then convert T.38 data back into T.30 data for reception. This translation happens at the fax server/gateway.

The fax server’s software bundle acts as a bridge between the two protocols. The fax/modem component converts analog fax signals into digital data on the sending end and digital data into fax signals on the receiving end. The fax/network component puts digital data into IP data packets on the sending end and takes those packets apart on the receiving end. The fax/protocol component coordinates the T.38 actual timing with the T.30 expected timing.

Another issue with IP faxing is network timing. Timing on the internet is not as standardized as timing on phone lines. If the timing in a fax session is off, the machines might not understand each other, and the transmission of information can end up corrupted or fail entirely. IP faxing experiences delays due to processing, network hold-ups, and jitter buffers.

Jitter buffers delay packets on the receiving end to compensate for variable timing in packet arrival. In most cases of poor timing, the gateway can negotiate with the receiving fax machine to keep the connection open until the transmission is complete. If a packet arrives out of order at the gateway, it can put it back into the right sequence by reading the sequence number included in each packet.

In the case of a lost packet, there is no sequence number to read and packets do sometimes get lost when dealing with a network like the Internet. However, FoIP has different error-correction methods to compensate for lost packets. One method is redundant packets, which is used when transmitting faxes via the UDP/IP protocol layer. This method includes each packet’s own data along with the data from the previous packet, so two consecutive packets would have to disappear for the data to be lost. Another error-correction scheme is built into the TCP/IP protocol layer, which requires a receipt confirmation for each packet it sends and resends the packet if there’s no confirmation. FoIP still has a ways to go before it’s as reliable as traditional phone-line faxing, but it’s a very attractive option for anybody who sends a lot of long-distance faxes due to its cost savings and network integration. For more information on FoIP and related topics, check out the links provided.

FAQ

1. What is FoIP?

FoIP stands for Fax over Internet Protocol. It is a technology that allows faxing over an internet connection instead of a traditional phone line.

2. How does FoIP work?

FoIP converts the fax signal into digital data, which is then transmitted over the internet using TCP/IP protocols. The receiving end converts the digital data back into a fax signal, which is then printed out on the receiving fax machine.

3. What are the benefits of using FoIP?

The main benefits of using FoIP are cost savings and convenience. FoIP eliminates the need for a dedicated phone line for faxing, which can save businesses money on monthly phone bills. Additionally, FoIP allows users to send and receive faxes from anywhere with an internet connection.

4. What equipment do I need to use FoIP?

To use FoIP, you will need a fax machine that is compatible with FoIP technology, as well as a high-speed internet connection and a VoIP adapter or gateway.

5. How secure is FoIP?

FoIP is generally considered to be as secure as traditional faxing, as the data is encrypted during transmission. However, it is important to ensure that your network and equipment are properly secured to prevent unauthorized access.

6. Can I use FoIP with my existing fax machine?

Yes, you can use FoIP with your existing fax machine as long as it is compatible with FoIP technology. Alternatively, you can use a software-based fax solution that does not require any additional hardware.

7. How reliable is FoIP?

FoIP can be just as reliable as traditional faxing as long as you have a stable internet connection. However, if your internet connection is unstable or prone to frequent outages, you may experience issues with sending or receiving faxes.

8. Is FoIP compatible with all fax machines?

No, not all fax machines are compatible with FoIP technology. It is important to check the specifications of your fax machine to ensure compatibility before attempting to use FoIP.

9. How much does FoIP cost?

The cost of FoIP can vary depending on the specific equipment and services you need. However, in general, using FoIP can result in cost savings compared to traditional faxing, as it eliminates the need for a dedicated phone line.

10. Can FoIP be used for international faxing?

Yes, FoIP can be used for international faxing as long as you have a stable internet connection and the necessary equipment and software. However, it is important to check with your service provider to ensure that their services support international faxing.

11. What are some common issues with FoIP?

Common issues with FoIP can include poor call quality, dropped calls, and failed transmissions. These issues are often caused by network or equipment problems, and can usually be resolved by troubleshooting the network or upgrading equipment.