Abstract:
The concept of voice over IP telephony emerged in mid 90’s and now has expanded as a
complete communications field within a short span of some years. Many standards have
been developed for IP telephony. IP telephony communicates voice over data networks
(LANs etc). Gradually the trend of IP telephony is increasing and in future most of the
voice traffic will go over IP Along with the data side by side because its charges are far
less than normal telephone charges.
The standard of IP telephony, which I choose to implement, is SIP (Session Initiation
Protocol). SIP is an application-layer control (Signaling) protocol for creating, modifying and terminating sessions with one or more participants.The multimedia transmission is implemented by the full implementation of by using OPAL (Open Phone Abstract Library). The SIP Server used is OnDO SIP server which provides proxy, Registrar and NAT Traversal.