What is the difference between VoIP and digital phone lines?

When it comes to a successful conference call, many things need to be considered. A well-planned agenda, a prepared host and participants, and effective teamwork all need to be in place. On top of all that, there are additional behind-the-scenes factors that can have a significant impact on the audio quality of your conference.

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For example, how the conference call participants are connected is important. Are they being connected by dedicated phone lines or Voice over Internet Protocol (VoIP) lines? 

How do VoIP and digital work?

While telecommunications technology has advanced significantly since the first telephone transmission, the basic premise of how a call works has stayed the same - speech is converted into a different format, sent via a connection to another party and converted back into an audible message. This is true of both digital telephone lines and VoIP. The finer details, however, are where differences emerge.

Both digital lines and VoIP convert audio into a digital signal before sending, but the manner in which that signal travels is not the same. Put simply, VoIP calls travel over private and public data networks - like the internet - while digital calls are sent through a dedicated line. 

While this may seem rather inconsequential, a more detailed look at the underlying technology of each method reveals far greater differences than expected.

Packet switching and circuit switching

While both digital and VoIP systems involve the transmission of signals, the way those signals travel through a network is quite different. Digital phone lines send signals through a circuit-switched network, while VoIP signals travel through a packet-switched network. In both of these networks, the connection travels through a series of switches. The way that happens, however, is slightly different in each.

In circuit switching, a two-way connection is established across switches between all the parties in a call. This establishes a full circuit where data can travel back and forth between the ends of the connection in its complete form. While the circuit is open, no other traffic is able to travel through it.

Packet switching, on the other hand, does not send data intact; that data is broken down into smaller packets, which travel along a number of possible paths to their destination. Each packet is marked with a destination address, as well as the instructions for how to recombine the packets in the correct order when they arrive. Those packets travel along any number of paths and through a variety of switches until they reach their destination. It is important to remember that packets do not necessarily travel together - each could potentially take a different route to the destination.

It is important to understand the way that a conference call signal travels through the different types of networks, as this is the underlying reason behind some of the pros and cons of digital and VoIP connections.

Should you choose digital or VoIP?

Most pros and cons of digital and VoIP connections are focused around setting up a business phone system. These include matters of cost, flexibility and mobility, among others. When it comes to conference calls, however, those are not as significant - the service provider will already have its network set up and configured.

Instead, with teleconferencing, other factors take precedence. Especially when it comes to clarity and security, which are of particular concern for businesses making conference calls, digital has clear advantages over VoIP.

For important conference calls, there is a distinct need for the host and participants to be able to hear each other clearly. Over digital phone lines, this is not an issue - they provide crystal-clear sound. VoIP, however, can be susceptible to call quality issues. According to Nextivia's Brian C. Andersen, the call signal over a VoIP network generally travels at speeds between 45 and 84 kilobytes per second. Excessive network traffic could slow down these speeds, preventing data packets from arriving at their destination at the same time.

As VoIP conference calls are transmitted through the internet, security becomes a concern. According to designDATA, unencrypted packets can be hijacked while en route to their destination. Encryption can be an adequate safeguard against this, but the risk is still there. Some systems use virtual private networks for additional security. This, however, has the potential to cause further delays in transmission speeds, exacerbating call quality issues resulting from slow packets.

Even if security measures prevent attacks from penetrating a network or stealing data from a VoIP call, there is still the risk of a distributed denial-of-service (DDoS) attack. Launched with the intention of shutting systems down by overloading them with requests, a DDoS attack can cause further issues for teleconferencing via VoIP.

At Eureka, our conference calls run through dedicated phone lines, to deliver optimal security and clarity. Get in touch today to learn more about our teleconferencing services in Australia.

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Topics: Teleconferencing

Last updated on March 28, 2019 11:35

Eureka Editor

Written by Eureka Editor