Sunday, June 29, 2008

simple code

simple code for execution voice transmission:

Main:

package newvoip;


public class Main
{

/** Creates a new instance of Main */
public Main()
{
}

/**
* @param args the command line arguments
*/
public static void main(String[] args)
{
// TODO code application logic here
}


Display form:

Friday, June 27, 2008

Requirements

the hardware and software requirements are listed below.
HARDWARE REQUIREMENTS
· Pentium IV processor
· 512 MB RAM
· 40 GB Hard Disk space
· Microphones
· Speakers
SOFTWARE REQUIREMENTS
· Windows XP/2000
· Java 1.6/Netbeans 5.0 and above

Monday, June 23, 2008

Protocols to be used

The following protocols are used for constructing the project body.
The core SIP specification defines six types of SIP requests, each of them with a different purpose. Every SIP request contains a field, called a method, which denotes its purpose. The list shows the six methods
1. Session initiation protocol(SIP).
*invite.
*ack.
*options.
*bye.
*cancel.
*register.
2.Real transport protocol.
Real-time Transport Protocol (RTP), which provides end-to-end delivery services for data with real-time characteristics, such as interactive audio and video. Services include payload type identification, sequence numbering, time stamping and delivery monitoring.
3.RTCP:
Real-time Transport Control Protocol (RTCP) is the optional companion protocol to RTP; it is not needed for RTP to work. The primary function of RTCP is to provide feedback on the quality of the data distribution being accomplished by RTP.

Friday, June 20, 2008

system design of voip project


The overview of the system design is explained and constructed.


The P2P VOIP architecture decentralizes the Call Processing Server by having a modified SIP client and server installed on each user's computer and by making intelligent use of Callee's SMTP server-log to obtain location information to initiate a VOIP call. Caller consults the Callee's SMTP server to obtain plausible IP addresses of the Callee. Callee's location is probed heuristically using IP addresses and timestamps obtained from SMTP server logs. Call parameters are then extracted from the SIP server running on the Callee's computer.The modified SIP client on the Caller's side contacts Callee's SMTP server and subsequently contacts the Callee's SIP and RTP to locate connection parameters, and finally initiate a call. This architecture essentially eliminates the need of a VOIP provider. Our approach works with an assumption that users use their computers to check e-mail periodically; and we can heuristically gather information about the user's location by intelligently traversing the SMTP server-log. Please note here that the called party is uniquely identified by his or her Email address. SMTP logs give location information (IP, Time stamps, etc.); and finally, a call is initiated directly between the peers using SIP handshaking and RTP/RTCP based communication

Tuesday, June 17, 2008

snapshots











Here are some of the snapshots for better understanding....

Friday, June 13, 2008

proposed system of my project


The proposed system of my project gives everyone a better security for voice transmission.

PROPOSED SYSTEM:
As with many new technologies, VOIP introduces both security risks and opportunities. VOIP has a very different architecture than traditional circuit-based telephony, and these differences result in significant security issues.
Firewalls are a staple of security in today’s IP networks. Whether protecting a LAN or WAN, or just protecting a single computer, a firewall is usually the first line of defense against would be attackers. Firewalls work by blocking traffic deemed to be invasive, intrusive, or just plain malicious from flowing through them. Acceptable traffic is determined by a set of rules programmed into the firewall by the network administrator. The introduction of firewalls to the VOIP network complicates several aspects of VOIP, most notably dynamic port trafficking and call setup procedures.
Only particularly security-sensitive organizations bother to encrypt voice traffic over traditional telephone lines. The same cannot be said for Internet-based connections.
"A firewall is a system or group of systems that enforces an access control policy between two networks or two systems."
Firewall vendors and those crafting standards are working to make firewalls operate effectively with the widely deployed protocol and the emerging Session Initiation Protocol (SIP), many users are skirting the issue by encrypting wide-area VOIP traffic and sending it over VPN tunnels for site-to-site and remote office connections. It eliminates the risk of exposing a network to intruders, which comes with opening ports on a firewall to allow VOIP to flow through.
The potential problems with sending IP voice through a firewall break down into two categories: network address translation (NAT) and the complexity of VOIP traffic.
NAT changes the source IP address of a packet from a private address to a public one so it can be routed over the Internet. The "NAT-ing" device, such as a firewall, keeps track of what the private IP address is, so returning traffic can be routed to the sending device.A VOIP firewall is an application driven by a security policy defining whether to allow or deny certain calls. To provide superior security, the firewall must be highly reliable and add no noticeable latency to voice traffic

Thursday, June 12, 2008

Disadvantages of my project!!!!

Though we benefit a lot from voip peer to peer services, it also suffers from some of problems.
They are:
· If the server goes down, then the entire network crashes.
· It is more expensive to install.
· Needs to be maintained by staff with high IT skills.
A peer-to-peer (or P2P) computer network is a network that relies on the computing power and bandwidth of the participants in the network rather than concentrating it in a relatively few servers. P2P networks are typically used for connecting nodes via largely ad hoc connections. Such networks are useful for many purposes. Sharing content files containing audio, video, data or anything in digital format is very common, and real-time data, such as telephony traffic, is also passed using P2P technology. The term "P2P network" can also mean grid computing.
A pure peer-to-peer file transfer network does not have the notion of clients or servers, but only equal peer nodes that simultaneously function as both "clients" and "servers" to the other nodes on the network.
But with increasing welfare, these are neglected and tried to overwhelm these difficulties

Monday, June 9, 2008

Advantages of my project


Many benefits can be obtained from my project. Some of them are listed below in points:

· The servers are designed to handle multiple requests from clients.
· Resources, security and files are centrally controlled which makes it easier to administer.
· The network is more scalable as it allows for more users to be added as the network grows, unlike the peer-to-peer networks, which are usually restricted to a certain number of computers.
The IETF proposed Session Initiation Protocol (SIP and RTP, RTCP etc.) to facilitate asynchronous multimedia communication (such as, VOIP and Video Conferencing). The IETF is well-known for its philosophy of freedom and adherence of non-proprietary but innovative protocols and standards. In our work, we tried to analyze relevant Internet protocols and implemented a light-weight SIP client and server modules to implement a pure P2P VOIP system. The system is implemented by having both the SIP client and server modules on end-user's computers.
Gaining these benefits, it is widely used by many of them.

My engineering project




My project in engineering was "Intelligent peer to peer voip"- the main purpose of this is to enable a voip user tracking and calling other users anywhere in the net.This architecture decentralises the mechanism of call establishment and call termination as well as user tracking without going through a centralised VOIP proxy or redirection server.The main advantage of the peer to peer network network is that there will not be any single point of failure that is even if a server in one system crashes it will not affect the entire network.
Network providers see VOIP technology as a means of reducing their cost of offering existing voice-based services along with new value added multimedia services. Service providers also view VOIP infrastructure as an economical base on which to build new revenue-generating services. As deployment of VOIP technology becomes widespread and part of a shared competitive landscape, this second goal will become more important, with service providers working to increase their market shares. However, this trend violates the philosophy of freedom behind the Internet. Internet users should be able to use VOIP as they have been using e-mail over the decades without having to pay to or tied with a particular VOIP provider.
I'll explain about this project in the following posts