How to Make Free VoIP Calls with Mobile SIP Client

If your company needs the latest developments of telephony in order to expand your availability all over the world and to get ahead of your competition, you probably want to know more about some basic facts about a protocol that controls part of it. That is why this article on SIP Clients has been written. It is suggested that you should read it.

When you want to call a VoIP Phone, a Computer, or another mobile device from your mobile phone, SIP (see the section on definitions below) establishes a connection. The data of the call arrives first to your VoIP provider (see the section on definitions below), then it gets to the SIP server. In the end it arrives at the PBX of Ozeki Phone System, where it is switched to the desired extension. (Figure 1) Public Branch eXchange switches calls within a local network.

voip calls with mobile sip client
Figure 1 - VoIP calls with mobile SIP Client

Definitions

Protocols are sets of rules, which define the order of a work process. Here, they define data transmission via the Internet. IP, or Internet Protocol is a special protocol, which provides special addresses (IP addresses) to each computer in the network, to serve as a destination where the data must get to.

SIP, or Session Initiation Protocol, as the name suggests, is also a protocol. Its main duties are starting, ending and maintaining a session, so it is used with multimedia sessions like video and audio calls and conferences.

A SIP Client is a program, which you need to install on your mobile device, to which it adds the funcionality of a softphone, or phone software that you can use to talk through VoIP (Voice over Internet Protocol, which directs the transmission of multimedia sessions in data packets via the Internet), without an actual phone.

So, it means that although you can install a SIP Client on your smartphone, you would not use it as a phone when making a VoIP call, but as if you were using it for browsing on the Internet or writing an e-mail or book, or something.

Advantages of using SIP on your mobile phone:

  • More than two people can be included in the conversation
  • Higher quality of sound
  • Possibility of video calls
  • Rich communication experience
  • Worldwide availability
  • No boundaries with restrictive laws

How to set up a SIP Client:

  1. Get a SIP account with a SIP provider, like Ozeki Phone System. You will get technical information like username and password.
  2. Install a softphone application, such as:
    • X-Lite
    • Ekiga
    • Jitsi
    • MicroSIP
    • QuteCom
    • Empathy
    • LinPhone
    • Blink
  3. Connect to the Internet (you will need one with broadband).
  4. Configure your application in its Settings menu.
  5. Create your new SIP account.
  6. Precisely add the necessary information, like display name, user name, password, domain and so on.
  7. You can configure some other settings, if you are an expert, or you can go to the next step.
  8. Confirm the configuration by clicking OK
  9. Test the service by making a test call or calling an available friend.

How to Use SIP Clients

If you are not sure you could use a SIP Client, let me explain to you how easy it is. When you make or receive a call, using a SIP client, is almost exactly like making a normal call on your mobile phone, except the fact that it uses the Internet instead of the Public Switched Telephone Network (PSTN is the old, outdated telecommunication network, which we used in the last century).

If you have a network with several devices, then you can use a SIP server to have voice and video calls, chat conversations, or conferences at the very same time within the network.

Ozeki Phone System uses SIP for the best possible way of communication, so it supports all SIP Clients. Ozeki Phone System offers you the most advanced, and most easy-to-use possibility to use the latest development of telecommunication.

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