How does SIP works in VoIP?

Posted on Jun 1, 2021

What is SIP?

SIP, abbreviation for Session Initiation Protocol (SIP) which is the signaling portion of the communication protocol that is commonly used by organisations in initiating, maintaining and terminating real time communication sessions such as voice, video calls and messaging applications. Hence, it is also a specific protocol that validates VoIP. 

SIP validates the messages sent between endpoints, it is primarily used to establish and terminate voice and video calls. Companies or organizations can use SIP to pass on information between two or multiple endpoints. It is standardized and launched by the Internet Engineering Task Force (IETF).

The philosophy behind the SIP creation is to provide simple, lightweight means for creating and terminating real time interactive sessions over IP networks. On the other side, SIP can be used for video conferencing, instant messaging, media distributions and other applications. It is crucial to be functionable and communicating in multiple ways and SIP is the technology that allows that flexibility. 

The significance of SIP 

SIP is the system of digital rules for messages exchanged between or within computers, phones or other digital devices. To enable the devices to communicate between each other, The developers of those devices must use well defined formats for exchanging messages. 

The protocol validates the semantics, syntax and synchronization of communication. Developers of the connected device or application (endpoint) have to incorporate SIP into it or in a simpler words, SIP enabled devices. For this reason, SIP has evolved to the industry standards, making it easier for multiple vendors to create endpoints to communicate with each other. 

In a nutshell, if purchasers want an all in one solution for their business communication needs, SIP trunking will be the best bet. Using it along with other further tools like Asterisk, allows SIP phones and communications platforms even better as they are now customisable to specific business needs. 

What is VoIP?

VoIP stands for Voice Over Internet Protocol, also called IP telephony, which is a way and consists of different technologies that enable voice communication and multimedia sessions over Internet Protocol (IP) networks. It covers any phone calls made through the internet as opposed to traditional telephone lines, or also known as Public Switched Telephone Network (PSTN). Terms like Internet telephony, voice over broadband, broadband telephony, IP communications or broadband phone services can be used interchangeably with VoIP. 

The multiple technologies involved used the internet to digitally pass on the voice signal to another endpoint or telephone. VoIP comprises a group of protocols technologies including Skype protocol and open standards which SIP is an example. Organizations commonly used VoIP along with an application like Skype or Google Talk and with IP enabled Private Branch Exchange (PBX) hardware or via a hosted VoIP service. 

A VoIP enabled phone and VoIP software are needed for customers to enable the most basic fundamental function of the system. With that, it is sufficient to create and receive calls through the internet. It is an ideal choice if you do not wish to rely on mobile phones or you want to eliminate the clutter of landline phones in the office. Customers are able to retain an official line for their business with VoIP set up. 

VoIP is only limited to voice transmission, thus it helps to keep usage to the minimum. 

The VoIP provider can even offer unlimited minutes for your customers to achieve a better deal. For the same reason, VoIP is hard to be replaced when it comes to price and practicality for basic voice communication. 

Implementation examples

When the term VoIP is mentioned, most people imagined a hosted VoIP solution where the vendor operates and hosts the PBX functionality that manages call handling, voicemail and other applications. Customer's IP enabled phones connect to the internet and eventually to the vendor’s software and servers. This is only just one type of VoIP implementation. 

SIP trunking brings unified communications and telephone services to customers by using SIP enabled PBX and unified communications solutions. The PBX in turns provides voicemail, call management, auto attendants and other call services. 

The SIP trunks create the connection between OBX and the public telephone network, replacing the use for legacy telephone lines or Primary Rate Interfaces (PRIs). This provides the businesses with the opportunity to select the IP-PBX software and hardware which work more efficiently and free them from the expenses and inflexibility of traditional phone lines and carrier relationships. 

VoIP is used in managed and hosted IP PBX. Hosting IP PBX is a hassle free task where your customers have a provider that oversees the entire thing for them. You may partner with a third party that offers this service or serve in this capacity. Your customers do not have to buy the hardware or set up the SIP trunking with a hosted IP PBX as they are getting a pre-configured VoIP system. 

A hosted IP PBX is perfect for companies that have lack of capital to execute a fully customised SIP trunking service. Since it involves hardware purchase and applications creation, if those companies lack the budget to do all that, they can go for the option of managed IP PBX. 

SIP technology is becoming the preferred method of implementing VoIP across the enterprise as it has better augmented efficiency, scalability and lower cost compared to other older systems. 

What are the differences between SIP and VoIP?

Regarding their differences, there really isn’t such a thing. SIP is an industry standard method of achieving VoIP. However, SIP is the preferred method because of scalability since the companies won’t be limited to voice communications and in turn is able to expand into video, instant messaging and many more. 

Businesses that are searching to improve their communications with lowered costs by moving to VoIP should consider the ways to implement it cautiously which includes SIP trunking and choose the one that gives the greatest benefits for them. It is not necessarily to understand the intricacies of SIP definition, but if the customers can appreciate the pros that SIP and VoIP bring, it is more likely to convert them to the modern communications platforms.