What is SIP Trunking?

How to / Guide

January 26, 2021

What is SIP trunking?

Simply put, SIP trunks allow organizations to make phone calls over the Internet, instead of through traditional phone lines. It provides access to, and from, the Public Switched Telephone Network (PSTN) over the Internet, while offering more flexibility and lower costs for inbound and outbound voice calls. Unlike traditional telephony, where physical wires are used by telecoms companies to connect to businesses phone systems, a SIP trunk operates over an existing broadband or leased line, so a company can replace their traditional fixed ISDN and PSTN lines with PSTN connectivity via a SIP trunk provider.


What does SIP mean?

SIP stands for Session Initiation Protocol, and is a specific application-layer protocol that was standardized in 1999 to make voice and video calls over the internet, establishing and terminating the connection between one or more endpoints (phones or computers). The technology supports one-on-one calls, as well as multi-party conference calls. SIP trunks are widely used today to provision VoIP connectivity (Voice over IP) between the PSTN and a business telephone system and are becoming even more prevalent with the acceleration of cloud phone systems.


How does it work?

SIP Trunks are linked to a customer’s current telephone system, which is either an IP enabled PBX or a Media Gateway (typically a more traditional PBX). When an outgoing call occurs, it is routed through the PBX via the SIP Trunk instead of using costly traditional phone lines. Using SIP trunks, providers can connect multiple channels to a company’s PBX, which makes long-distance and international calls easier and, usually, more cost effective.


Why do businesses need SIP Trunking?

As companies shift towards a digital environment for calls and communication, and countries around the world announce the end of life of their PSTN and ISDN services, SIP is now essential for establishing, managing, and handling calls.

With SIP trunking, businesses can continue to unlock the greater flexibility and opportunities presented by cloud technology for the maintenance, monitoring, integration, and use of their telephone system. Moreover, because everything is managed through the internet with SIP trunking, businesses can benefit from more reliable connections, higher versatility, and lower prices.


What are the benefits of SIP Trunking?

Converting to a digital telephony environment using SIP trunks can not only provide cost savings of on international calls, but offers a wide range of benefits including:

  • Mobility: SIP helps organizations to connect employee devices, such as laptops and mobile phones, to flexible VoIP and UCaaS systems that are secure and reliable. This means that companies can access all the benefits of remote and distance workers easily.
  • Reduced physical infrastructure: Managing an organization’s infrastructure in a traditional environment can be challenging; SIP solutions make it easy to add and remove phone lines at the touch of a button. All you need to do is connect a device to a data connection and you’re ready to go.
  • Speed of provisioning: SIP trunks make it faster and simpler to order new voice services, such as numbers or channels. SIP suppliers like Pure IP provide their customers with an online portal they can use to place orders, which can be live in just hours!
  • Network consolidation: You don’t have to pay for data and voice services separately with SIP trunking. This makes it easier to reduce costs, improve bandwidth performance, and enhance the reliability of your calls.
  • Future development: SIP allows you to optimize for the latest technologies and applications, providing a solid foundation for future development and growth.
  • Improved customer service: You can provide better customer service with SIP trunking, because it’s easy to access quality geographical and international numbers. This gives customers more options to call your business at lower costs to them.
  • Global potential: SIP supports the fast growth of an organization across multiple locations. Plus, it’s possible to consolidate data and voice information into a single network, for easier tracking too.
  • Rerouting calls: While traditional phone services frequently suffer from interruptions due to issues like telephone pole maintenance and inclement weather, SIP trunking solutions can help prevent disruption by rerouting calls to bypass network issues.

With SIP trunking, your company can enjoy an all-in-one environment for enhanced communications, with 24/7 visibility over your entire network and access to user friendly online portals for stress-free management.

It presents a compelling opportunity for businesses that want to improve their communication stack today, as well as enable future development, for minimal cost. By investing in SIP trunking solutions, your business can, not only, futureproof against the end of PSTN and ISDN services, but also be in a position to take advantage of cloud communications, and the solutions that come next.

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Alessandra Skarlatos

Alessandra joined Pure IP as the Content and Communications Manager in early 2020, after 5 years within the cinema technology sector.

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