SIP is one of the most common protocols for implementing VoIP technologies. The protocol is used in IP telephony to initiate, manage, and terminate voice and video communication sessions over IP networks. It defines how phones and other devices establish, maintain, and end connections. From the perspective of modern business, SIP trunking is an economical, flexible, and scalable form of communication that integrates all communication channels into a single network. We offer you a quick guide on SIP telephony: what it is, the main concepts of the technology, its advantages for business, and development prospects.
Protocol SIP: what is it?
TechTarget experts define SIP (Session Initiation Protocol) as a signaling protocol used to initiate, maintain, modify, and terminate real-time sessions, including video, voice, text messaging, and other communication applications and services between two or more endpoints in IP networks.
Need a clearer definition? No problem! SIP is a virtual phone line (SIP trunk) that allows making and receiving phone calls over the Internet between any devices (phone numbers), regardless of whether VoIP telephony or traditional public switched telephone network is used.
How does the SIP protocol work?
The SIP protocol operates using server messages sent from one SIP profile to another through physical PBX servers or private cloud PBXs. Simplified, the operation of the SIP protocol looks like this:
- A SIP client initiates a connection by sending an INVITE message to the SIP server – a connection invitation.
- The SIP protocol defines the parameters necessary for this connection: the IP address of each SIP profile, ports, and media codecs to be used, message data formatting.
- The SIP server sends a request to the other subscriber, with each endpoint being notified of readiness to connect with session attributes set for each participant endpoint according to the device.
- Once all attributes between SIP profiles are agreed upon, data packets begin to be transmitted via RTP – real-time transport protocol.
- When one of the subscribers hangs up, the SIP protocol sends a signal to the server to end the session.
Clear and transparent, right? But the capabilities of the SIP protocol don’t end there. It also handles adding participants during an ongoing connection, transmitting text messages during a voice call/video call, and redirecting communication sessions to other devices or phone numbers.
What do you need for SIP trunking?
To use SIP telephony, you need to have at least one piece of equipment from this list:
- VoIP phone capable of transmitting voice messages over the internet protocol;
- Analog phone connected to an IP gateway and router;
- PC, laptop, or tablet with internet access and installed VoIP calling software;
- Mobile phone with SIP software installed.
Of course, to use SIP telephony, you need to find a reliable service provider that ensures the stability of SIP trunking and the security of SIP servers.
Advantages of SIP trunking for business
In the turbulent world of business, companies are constantly seeking more efficient solutions to increase revenue and reduce costs. SIP trunking is suitable for businesses of any size that require a flexible and cost-effective phone system with the ability to scale quickly. SIP technology offers numerous advantages, from cost-effectiveness to ensuring business continuity. Let’s take a closer look at these advantages.
Cost reduction
Analysts have calculated that using SIP trunking reduces communication costs by 25-60%. Leading SIP providers offer advantageous rates for long-distance and international calls, as well as free tariffs for calls within the company. Using virtual numbers allows for savings on registration and maintenance of numbers in different cities and countries. Additionally, the implementation of SIP telephony does not require additional investment in physical equipment, as providers primarily use virtual PBXs and cloud-based software.
Easy setup
Imagine a company opening an office in another country. How much effort would it take to set up a call center or back office back office process? Setting up a SIP-based hosted phone system takes just a few minutes! You simply need to download the software from the service provider onto employees’ devices. It practically requires no technical maintenance or end-user experience, as SIP trunking services typically offer 24/7 technical support outsourcing service .
Advanced phone system features
SIP-based business telephony offers many additional features, such as:
- Call forwarding and automatic call distribution (ACD) systems;
- Integration with multi-level IVR menus;
- Integration with online chats and messengers;
- Integration with CRM systems;
- Connection of information panels.
Thus, SIP trunking combines all the functions of a phone system and provides a comprehensive view of communication tools’ effectiveness.
Mobility and scalability
SIP trunking for businesses allows for easy consolidation of company offices and remote employees regardless of their geographical location. This advantage becomes particularly important with the rapid adoption of hybrid workplace arrangements. When employees are not in the office, they can be reached using the same number they use in the office. This is convenient for internal communication between employees and departments, as well as for business communication with customers.
SIP channels allow for easy addition and removal of users, including remote employees. This can be useful for contact centers or technical support centers that depend on seasonal call volume fluctuations. The mobility of SIP telephony also comes into play when changing service providers, as all existing phone numbers can be ported, and new connections and numbers can be added from the central IPS server.
Resilience and security
Virtual PBX providers providers pay maximum attention to securing their PBXs. This involves a set of actions that eliminate major threats, such as interception (eavesdropping) of information, hacking, data manipulation, and network availability restrictions. Measures include:
- Transport Layer Security (TLS) protocol;
- Encryption systems;
- Authentication and authorization methods to protect against unauthorized access;
- IP address filtering;
- VPN services.
Since SIP service providers have connections with multiple carrier networks, there is no single point of failure. This means that when the primary operator’s network fails, the backup SIP channel provider can route calls through another network. Business continuity is also ensured by backup and data recovery systems. These systems may be included in the basic settings of SIP trunking services or customized according to the requirements, budget, and specifics of each business.
SIP trunking development prospects
As analog PBX systems are being phased out worldwide, cloud technologies advance, and the telecommunications industry continues to evolve, it’s important to consider the future of SIP telephony.
It is expected that by 2026, the global SIP trunking market will grow by 10.5% annually. This is driven, firstly, by the increasing demand for cost-effective communication solutions, prompting enterprises to transition to SIP telephony as it provides significant savings by utilizing existing Internet connections.
Secondly, the scalability and flexibility of SIP trunking services meet the dynamic needs of modern enterprises, allowing them to adapt seamlessly to changing communication requirements. Furthermore, the proliferation of SIP services is facilitated by the global shift towards remote work.
Additionally, market growth is expected to continue based on the integration of SIP trunking into CCaaS (Contact Center as a Service) call center outsourcing. By integrating these technologies, enterprises can create a seamless communication experience for their employees and customers.
