Linphone "open souce voip project"

You just downloaded Linphone on your iPhone, Android or Windows Phone 8. Great ! But what happens now ? What's that complicated settings view?
Let's go to the basics: before being able to place calls to any number worldwide, you need to purchase a SIP account from a VoIP operator or you can use our free SIP service. The VoIP operator's role is to transform a pure internet VoIP call into classical PSTN call, thanks to a set of machines called gateways.
Linphone is a general purpose SIP softphone that isn't bound to any operator. Because it is compatible with SIP, it can work with any VoIP operator using SIP (most of them use SIP, the most notable exception being Skype). Linphone.org is not affiliated nor recommends a VoIP operator in particular. We invite you to select a VoIP provider in your country by browsing the web, and compare rates etc…
Note that you might have a SIP account included with your internet line subscription: it is the case in France for clients of the free.fr internet provider, who is powering the freephonie.net VoIP network.
Ok I have now a SIP account at some-voip-company dot com, what do I do?
Go to the settings page of Linphone. On android it is accessible through the "menu" button, on iPhone the settings are located within the Settings application, together with all other iPhone settings. You'll have to enter at least three things:

• Username
• Domain
• Password

All this information should be provided to you by your VoIP operator during signup process. For your information, username and domain form your SIP identity when grouped together like an email address:
sip:my_username@my_voip_provider
Sometimes, VoIP providers might require to setup also the "Proxy" field. This happens when the domain is different from the proxy.
And that's all. Once returned back from the settings page, Linphone should say something like "Registered on XXXX" or "Registration on XXXX successful".
You can now place calls.
All other settings are for advanced users or geeks who want to play with the software.

International Data Corporation (IDC)

International Data Corporation (IDC) is the premier global provider of market intelligence, advisory services, and events for the information technology, telecommunications and consumer technology markets. IDC helps IT professionals, business executives, and the investment community make fact-based decisions on technology purchases and business strategy. More than 1,100 IDC analysts provide global, regional, and local expertise on technology and industry opportunities and trends in over 110 countries worldwide. For 50 years, IDC has provided strategic insights to help our clients achieve their key business objectives. IDC is a subsidiary of IDG, the world's leading technology media, research, and events company.

IDC is a wholly-owned subsidiary of International Data Group (IDG), the world's leading technology media, events and research company. IDG’s media brands – including CIO®, CSO®, Computerworld®, GamePro®, InfoWorld®, Macworld®, Network World®, PCWorld® and TechWorld® – reach an audience of more than 280 million technology buyers in 97 countries. IDG’s network features 460 websites and 200 print titles spanning business technology, consumer technology, digital entertainment, and video games worldwide. The IDG TechNetwork represents hundreds of independent web sites in an ad network complementary to IDG’s media brands. IDG® is also a leading producer of more than 700 technology-related events, including Macworld | iWorld, E3 Expo®, DEMO®, SNW™, and IDC Directions®. IDG’s marketing services include lead generation with IDG Connect®, custom publishing, social web marketing with IDG Amplify® ads and IDG Social Scout™ analysis and program development, and IDG Market Fusion™ research and content optimization.

 VoIP and the OSI model

VoIP follows a layered model comparable to the OSI seven layered model we are familiar with.  Just like the purpose of developing the OSI model, breaking into defined layers provides a framework. It establishes a standard to make the system more manageable and flexible. Each layer is relatively independent to other layers around it. Changes made to one layer should have no, or minimal impact on other layers.

 

   Configuration

• There are several VoIP configuration options available. The first option is telephone connection with the VoIP gateways. The VoIP gateways, which provide encoding, compression and encapsulation functions, translate the voice signals to data signals, and vice versa. The second option is PC connection with routers. The router is used to verify the destination IP address in the packet and transmit the traffic subsequently. The encoding, compression, and encapsulation processes are all completed at the PCs, not routers. The third option is telephone-to-PC connection. With this operation, the routers are added extended capabilities and functions from a VoIP gateway.
  
  
   

 

Why VoIP?

The Internet Protocol (IP) is used to deliver packets carrying digitized voice. However, IP was not designed for real time traffic such as voice and video communication. IP is a connectionless protocol meaning a virtual connection is not established through a network prior to transmission. IP makes no guarantees concerning reliability, flow control, error detection or error correction. Potential errors include out of sequence packets or even loss of packets. Voice transmission requires guaranteed connection and a reasonable delay.

Nevertheless, IP succeeds partly due to the high cost associated with the traditional circuit switched TDM network. VoIP uses packet switched network. It makes the network transparent to the upper layers that are involved in voice transmission through an IP based network. The existing use of IP network also allows the integration of voice and data integration. To leverage the connectionless nature of IP, vendors have developed higher layer protocols to address the guaranteed connection and transmission issue.

 What is VoIP?

Voice can be digitalized. The digitalize voice can be transmitted in packets over the network. Voice transmission comes in different flavors. In the past, telecommunication through fixed circuit switched network has dominated. In recent years, we see data communication networks, especially voice over IP. Voice over IP is the transmission of voice traffic in packets using the Internet as the transmission medium. IP is used rather than the traditional circuit transmission.