nixCraft

Hello,,
I want to deploy VOIP Gateway on linux machine.I need step by step guideness in plain words regarding this matter.

regards

Hi,

Do you need to install just a free gateway or a AAA server for the VoIP too (and the VoIP will be paid in the last case)??

There are a lot of hardware and software for these purposes. As a VoIP gatekeeper I could suggest Asterisk or GNUGK or OpenSER, that's up to you.
As an example, setting up GNUGK can be found in this manual, page 226. Also you will find there how to set up GNUGK with a RADIUS server for AAA (authentication, authorization and accounting).

"the future of telephony - edition version 2" free pdf from o'reilly
openser docs
vovida docs
etc. 'google'ing, as info is less in post.
plus VoIP gateway as in what kind of gateway you are grabbing the mud to stick to your feet?
Network -> VoIP (IP to IP) -> Internet -> ABCXYZ Network (SIP/IAX/MGCP/SGCP)
Network -> VoIP (IP to PSTN) <- & -> Internet (SIP/IAX/MGCP/SGCP)
bandwidth of the network if 1000 mbps = 1000 /8 KBps, then if you use open g729 then you end up 8 KBps. if you use speex? you end up using 6.8 kbps.
anyway hopefully this helps, since the question was vague, the answer was a guess. let us know more about the possible possibilities acheiveable with minimum effort.