What is SIP Trunking (Session Initiation Protocol Trunking)?

In this page you can get informed about SIP, trunking and SIP trunking in general. You can get to know the differences between this and the calls managed on simple lines. This page informs you about how SIP trunking is used in practice. In the end, you can read about the role of SIP trunking in advanced telecommunication like your Ozeki Phone System.

SIP trunking is a tool that you can use for managing several calls in the same time. SIP trunk lines are connected to the PBXs and the devices. The role of SIP trunk lines is to provide several communication channels in a single physical line.

As Figure 1 represents, SIP trunking has an important role in a well-built communication system. The SIP lines of the several SIP clients are collected into a SIP trunk line. The SIP trunk line is connected to the SIP server, your Ozeki Phone System. This server is connected to another SIP server through the Internet.

sip trunking in practice
Figure 1 - SIP Trunking in practice

One of the most significant advantages of Session Initiation Protocol trunking is that it is capable to handle almost every kinds of data (including voice and video) in one single wire. This makes it possible to avoid separate physical media for each data type. This results that the reliability for multimedia services becomes much higher.

SIP, Trunk and Trunking

The SIP (Session Initiation Protocol) is used for setting up the different types of real-time calls: chats, audio calls, video calls, chat/audio/video conferences.

Trunking is the use and management of trunks. A trunk is a line or link constructed to handle many signals simultaneously. It's similar to the trunks of the trees in nature: it connects major centers in a communication system.

Trunking reduces the number of required physical paths (actually, the number of cables and wires) to the minimum.

The word "SIP trunking" also means that the devices use the SIP protocol.

Where, Why and How Is SIP Trunking Used?

SIP trunking is used for managing calls that are made simultaneously.

In practice it means that:

  • when you are using one of your phones, it will indicate a new incoming call, instead of automatically sending a busy signal to the caller.
  • you can change your partner during a phone call and make the other hold the line until you change the call back on them
  • in the case of call centers, several, maybe hundreds of calls must be managed simultaneously - that is impossible without SIP trunking

For having SIP trunks, you have nothing else to do but to order them from a VoIP service provider. The VoIP service providers provide SIP trunking service. The VoIP service provider is going to build up the SIP trunk lines. SIP trunks are connected to the corporate PBX by the VoIP service provider.

After building up the physical lines, it is the PBX's task to manage the calls. The Ozeki Phone System can manage these connections according to the highest demands, with absolute professionality and maximum reliability.

With SIP trunking users can:

  • make and receive local and long-distance calls as well, and these calls can be managed simultaneously
  • use desktop and mobile telephone devices

The Ozeki Phone System users can make numerous VoIP calls simultaneously. They can talk with more than one person in the same time in a conference, using a troublefree, modern and superb technology for their communication.

In the traditional communication systems, one phone had one phone line, and only one call could be managed from a phone. With SIP trunking, you can forget this restricted way of communication: SIP trunking makes it possible to handle more than one calls simultaneously with one device, on one phone line.

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