VoIP, SIP Trunks and Landlines – Basic Terminology

With the upcoming BT ISDN Shutdown, more and more businesses are making the transition to VoIP.

Click here for further reading on VoIP vs Landlines, the benefits of VoIP and making the switch

Here are some terms you may find useful to understand.

VoIP: Voice over Internet Protocol
A telephone system that runs phone calls over the internet rather than over a dedicated telephone line.

VoIP phone
A phone that receives the voice data in its own internal system, this includes mobile phones. This system for telephony can be hardware or software based.

BYOD: Bring Your Own Device
Essentially this means that employees can use their own, personally selected and purchased device to use for business purposes. This includes smartphones, laptops and tablets. The devices would operate within the company’s secure corporate network and may be subject to additional security measures.

Cloud Communications / Cloud Telephony
This is where the telephone communication and voice data are hosted on the internet (i.e. the Cloud). Cloud Telephony is considered to be outside of the hardware and software systems of the company using these services.

PBX: Private Branch Exchange
This in a private / in-house telephone network used company-wide. It allows users to communicate internally with each other and to outside of the company. A PBX allows free calls between users and is outside of the telephone network which is known as PSTN (or landlines).
With this is mind, it is important to note the distinction between a traditional PBX and a hosted PBX. A traditional PBX system is located onsite and is restricted to internal company usage only. A hosted VoIP PBX uses internet protocol to transport calls, this essentially means that you can make phone calls remotely as if you were in the office.

SIP: Session Initiation Protocol.
This is a standard or set of rules for starting, maintaining and ending an interactive user session be it video, chat, gaming and more. The SIP protocol is the basis of VoIP.

SIP Trunks – to take over ISDN in 2025
A SIP Trunk (also known as a SIP Phone Line) is the modern standard for business telephony. It is VoIP service that connects the phone system (PBX) to the PSTN (telephone network) using the internet. It acts as the virtual connection to the PTSN utilising an internet connection. For example, enabling VoIP services by connecting a PBX to the internet or an ITSP (Internet Telephony Service Provider).

SIP Phone:
This phone uses SIP to make a voice call over the Internet.

ITSP (Internet Telephony Service Provider)
These are the businesses that provide and host digital communications.

ISDN: Integrated Services for Digital Network
A digital version of the telephone line, established in the mid 90’s for telecommunication using traditional copper line networks. This was the first service to allow businesses to send data, such as voice calls or images, through their phone lines using the internet. ISDN will be switched off by 2025 to be replaced with ITSP.

PTSN: public switched telephone network
This is a physical phone line also known as landlines or fixed-line telephones. Calls are made over copper telephone lines and fibre telephone lines using analogue signalling, this is known as “traditional telephony”. PTSN will be switched off by 2025 to be replaced with ITSP.

Are you ready to make the switch to VoIP? Let’s get started! Contact us to get the ball rolling.