Coding examples of extensions in asterisk using SIP

Asterisk Asterisk Support
1

Hi All,
I want to write codes for extensions in asterisk. What material should I refer for getting started. I need to write codes to add SIP extensions and call from one extension to another.

Thanks,

2

Look at:
voip-info.org/wiki-Asterisk+RealTime
Use it as start point.
Then you can check Asterisk TFOT - you can find it with Google, download it and read it.