29-08-2014, 02:32 PM
To Design a Simple SIP Server using a Linux based OS Elastix . It is a calling Server used in IT industry to provide communication to all over the world using IP phones or soft phones in machines. As IP based computer network communications grows, Asterisk faces ever increasing success. Being free for all when compared to the enormous prices of the current brands in the market, in addition to having various potential capabilities with adequate quality, standard protocols, not being limited/depended to a particular brand of software or hardware, easy to install & operate, the sheer size of its third party developer community & most importantly, unified voice (whether voice or telephone), visual & data services have made Asterisk as a soft switch to become one the effective & dynamic components of the next generation of communication.
Contrary to many, not only Asterisk and basically soft switch idea, audio and video communications based on network application is not in conflict with traditional view of telecommunications but also it has complement and developer role. Although Asterisk is popular, its communication based on computer network (Video Conferencing, IP Technology, VoIP, etc...) is cheap and extended, but justification with traditional structure, generally TDM, is not forgotten in Asterisk and more importantly communication media has no effect in its operation. Set up Asterisk based on IP Based equipment is easier and cheaper but justification with older technologies should be considered as well. Security and reliability of operation in soft switch systems and Asterisk in compare with traditional communicative systems is a reason of conflict between soft switch and traditional ideas. Encryption of communication is the best way which line tapping and having fast computers cannot decode it. In addition to common ways, proprietary protocols can be made in encryption of communication. This is possible because of capability of Linux operating system and for providing the communications security between systems components based on Asterisk both common encryption and propriety protocols can be used. Beside this Linux is an appropriate firewall that can guarantee the security coefficient of accessing the Asterisk services to the high level beside other firewalls.