October 9, 2021 margarita

Voice Over IP Technology and Telecommunication Environment

Antonis Psaras | Microbase Managing Director

Voice Over IP is now the standard way of providing telephony services regardless of type, medium or size. All voice services, fixed and mobile, at some point along the way, are converted into VoIP, while the transfer of this point has already reached the end of the client.

Double Play services, home and small business, SIP Trunking services of larger companies, and now VoLTE services for all mobile users, use Voice Over IP technology and specifically the SIP protocol.

This change has brought significant changes in the way, accessibility and availability of the voice service, but at the same time it has brought significant changes in the way the service is received and managed by the end users.

Under what conditions does internet telephony
operates safely and with quality?

In this article, I will try to present in a simple way the necessary conditions for a safe, quality and trouble-free interface to the SIP Trunking services of the providers.

The Environment

Voice Over IP is a technology that converts voice to data and transmits it over data networks. The use of data networks for voice transmission raises questions about the separation of voice and data traffic over the same medium, its transmission security, as well as the way of shielding call centers that should receive this service.

The most common ways to provide the service are:

  • Via dedicated circuit, where only voice data passes over it and usually belongs to the provider’s independent voice network, without access to the Public Internet.
  • Via Public Internet using VPN to separate and protect voice data.
  • Via Public Internet using voice encryption.
  • Via Public Internet without any protection.

The majority of Greek providers choose to provide the service through Dedicated circuits and some of them use the Public Internet solution without any protection. Few providers in Greece offer the possibility of VPN and encryption or a combination of them. In any case, a provider data connection should go through the customer’s perimeter and end up in the call center, which, in most cases, is not able to deal with possible anomalies, attacks, compatibility with the infrastructure of each provider etc. This is where the need to change the design for hosting the service begins.

Cloud 1600x675 voice IP

The shielding of the call centers for the use of VoIP telephony is necessary

The options

As I mentioned above, voice now travels through a data network, just like the Public Internet. Since we would never connect our network to the Public Internet without perimeter protection, so the connection of the voice service directly to our call center, is out of the question.

But beyond security issues, VoIP technology has many elasticities, allowing each manufacturer to implement service in a different way. A small change on the part of the call center provider or manufacturer, may deactivate the service. The solution to the above problem is to use specialized software or hardware called Session Border Controller or SBC.

Session Border Controllers offer the ultimate telecommunication security

SBCs are equipment or software, which is placed on the perimeter to receive the provider’s VoIP line, acting both as a specialized voice firewall and as a translator between the provider’s equipment and your call center. This equipment is responsible:

  • to hide the customer’s telecommunications infrastructure from the provider and the Public Internet,
  • to repel any attack,
  • to reshape communication to be compatible,
  • to encrypt and decrypt communication,
  • to prevent suspicious calls (fraud) and
  • to protect the overall telecommunications infrastructure of the customer from malicious actions.

SBCs are offered in different types and are priced based on features and channels. They can be purchased as Appliances (Hardware and Software together), as Virtual Machines (Software) or as a Cloud service.

Configuring SBCs is not easy and requires special knowledge. After their installation, however, they operate continuously without special need for intervention. The choice of the partner for their configuration is very important, since the knowledge of both telecommunication and network security, is imperative.

Microbase’s goal is to maintain the Business Excellence,
which has been conquered in all its years of operation.


Microbase is a company with extensive experience in telecommunications and security. It is licensed to provide VoIP services and has a team of Engineers to research and develop telecommunications products, used by hundreds of our customers around the world.

Our Engineers have extensive experience and daily friction with VoIP infrastructure and know at a proficient level the issues of telecommunications security and how to configure SBCs to deal with them. We have implemented SBC at a provider level for their interconnection (Carrier To Carrier) and for value added services of large providers, with capacities exceeding 40,000 simultaneous calls.

The Solutions we offer cover all needs and sizes, from 10 channels to Solutions of a few thousand channels. They are provided in Appliance, Virtual or in Cloud with the ePhone Cloud SBC Solution. At the same time, Microbase, as a licensed telecommunications provider in Greece, provides VoIP services through SIP Trunking, covering all ways of interconnection or a combination of them.

The Experienced Microbase Engineers carry out comprehensive studies
for the telecommunications infrastructure of our customers