The little Asterisk Handbook

Few years back when i started working on VoIP deployment. Asterisk was definatly comes out of my first choise was Asterisk…as mostly you all guys do.If you are still not familier with the Asterisk and just want to Try it out at the weekend "The  Asterisk Handbook " proves to be worth reading for deploying Stuff in Less time.But prerequesties is fimilierity with Linux command line of you favourate Linux distribution.Besides it is concise,It is Written by Mark Spancer itself with Mark alison,Rodes and Asterisk Documentation Team. If you want to learn additional functionality read the "dialplan configuration" chapter in Asterisk : future of Telephony.

Another book you will need for helping you out in  Linux lcommand line and want some detailed discription,The book named "Asterisk :Future of Telephony" provides great resource.

Asterisk : Future of Telephony is Bible of Asterisk Administration a great Reference for every thing you would ever need as a Asterisk Expert from Medium to large enterprises including hardware configuration.Future of Telephony mainly written for Redhat Enterprise Linux and Centos System but applies to other Linux distribution as well.

voip_softswitch

A Soft Switch is Main device in the telecom network which can a Computer running Linux With Asterisk or any other VoIP software at the top of it and connects call from one Phone Line to another hence using the packet switch Technology.At the beginnig of the telecom age this work was carried by hardware with Switchboard to route call to the destination ( Circuit Switched ).

World’s largest SIP soft switch facility at Globe7,London

Other functional aspects of calling such as Telecom billing,Routing,call services are handled by Call Agent which controlled different media gateways which can be anywhere around the globe over a Internet Link ( usually Broadband ).These Media gateways can as disperse as PSTN Networks like E1 or an ATM ,IP Network connected to the Ethernet port of a computer systems,Soft switch connects call between them transparantly peer tp peer ( End points ) .Soft_switch generally resides in a building owned by Telecom or VOIP company.

VoIP - Voice Over IP

Voice over Internet Protocol (VoIP ) is a protoco optimized for the transmission of voice through the Internet or other packet switched networks using VOIP Codecs and VoIP is often used to Define Real Time Voice Transmission instead of the protocol implementing it. VoIP is also known as IP Telephony , Internet telephony , Broadband telephony , Broadband Phone and Voice over Broadband .Regular house phones i.e Traditional Phones can make VOIP Calls using analog telephone adapter (ATA) provided by the VOIP company or purchased from a third party VOIP Hardware Vender.

Telecom or Networking Companies which provides VoIP service are commonly referred to as VOIP Providers, and protocols which are used to carry voice signals over the Internet(IP network ) are commonly referred to as Voice over IP or VoIP protocols. They are commercial realizations of the experimental Network of Network Voice Protocol (1973) invented for the ARPANET providers. Main Advantage of VOIP Over The Other Networks is due to utilization of single network to carry voice and data creating a Unified Communication Environment,Becouse users have existing underutilized network capacity that can carry VoIP for no additional cost for End Users. VoIP to VoIP phone calls are mostly free, while VoIP to public switched telephone networks, PSTN , in which the End User ( VOIP User) need have to pay the cost.

Voice over IP protocols carry telephony signals as encoded digital audio, typically reduced in data rate using VOIP data compression codecs in which data encapsulated in a data packet stream over IP.

There are two types VoIP calling : Direct outward Diling (DOD) and Direct Inward Dialing (DID) which need access numbers . DID will connect the caller directly to the VoIP user while access numbers require the caller to input the extension number of the VoIP user.

Telecom in India

Telecom Services in India gone a hough chance in recent years,while the market penetration is still low as 22.52% , India Stands one of the largest growing market in the world adding 6 million mobile phone every month India expects to reach 600 million mark by 2010.

As the rates of calling decreasing day by day even acquiring the cheapest call rates in the world ,the indian Telecom providers keeping there profit margins by providing Internet BroadBand Services.The State owned Telecom Company BSNL is heading the broadband Revolution in the country by Providing Broadband Services as Cheaper as $3 per Month using existing Infrastructure by upgrading itself to ADSL Technology.

Telecom communications and Profit margin can only be sustained if operators are able to switch to voip communications.As vodafone telecom has entered in India Telecom Industry it chould be expected to provide voip communications as it is doing in Europe. voip providers and telecom companies in India can play a complementary role to cheaper yet maintain quality service.