Likely one of the most sincerely full conversations with regards to SIP was whether Session Border Controllers (SBC) are acceptable or detestable.
SIP was structured with the vision of changing the manner in which correspondence administrations are created, sent and worked. Following the start to finish soul of the Internet SIP should turn down the walled nurseries of PSTN systems and free correspondence administrations from the grip of huge telecom administrators. By moving the knowledge to the end frameworks, engineers should have the option to grow new correspondence benefits that will enhance the manner in which we speak with one another. This was to be accomplished without sitting tight for the endorsement of the different media transmission normalization gatherings, for example, ETSI or the help of officeholder telecoms.
Meeting fringe controllers are typically actualized as SIP Back-to-Back User Agents (B2BUA) that are set between a SIP client specialist and a residential ip proxies. The SBC at that point goes about as the contact point for both the client specialists and the proxy. Along these lines the SBC really breaks the start to finish conduct of SIP, which has driven different individuals to regard the SBC as a detestable manifestation of the old telecom perspective. Notwithstanding this restriction, SBCs have become a focal piece of any SIP sending.
In this paper we will initially give a concise diagram of how SIP functions and the highlights it supports, for example, NAT traversal, intercession, DoS insurance and backing for lawful necessities.
An increasingly nitty gritty rendition of the paper is accessible under out page.
A Short Introduction to SIP
By the mid nineties the IETF, which is assuming the job of the gauges association of the Internet, had just delivered various conventions required for IP-based communication administrations. The Real-Time Transport Protocol (RTP)  empowered the trading of sound and video information. The Session Description Protocol (SDP)  empowered the exchange and description of sight and sound information to be utilized in correspondence meeting.
The Session Initiation Protocol (SIP)  was the endeavor of the IETF people group to give a flagging convention that won’t just empower calls yet can be likewise utilized for starting any sort of correspondence meetings. Subsequently, SIP can be utilized for VoIP similarly just as for setting up a gaming meeting or controlling an espresso machine.
The SIP determinations portray three kinds of segments: client specialists (UA), intermediaries and enlistment center servers. The UA can be the VoIP application utilized by the client, e.g., the VoIP telephone or programming application. A VoIP entryway, which empowers VoIP clients to speak with clients in people in general exchanged system (PSTN) or an application server, e.g., multi-party conferencing server or a phone message server are additionally actualized as client operators.