SIP Protocols & Call Flow Fundamentals Flashcards

What does SIP stand for in telecommunications?

Answer: Session Initiation Protocol

SIP is an acronym that stands for Session Initiation Protocol. It is a crucial signaling protocol used in telecommunications for establishing, managing, and terminating real-time multimedia communication sessions over IP networks.

What is the primary function of SIP?

Answer: Control multimedia communication sessions

The primary function of SIP is to control multimedia communication sessions, such as voice and video calls, instant messaging, and other real-time applications. It handles the signaling aspects, including setting up, modifying, and tearing down these sessions.

Which SIP message is used to initiate a call?

Answer: INVITE

The INVITE message is a fundamental SIP method specifically used to initiate a call or session. It signals the intention to establish a communication session and carries essential information about the caller's media capabilities.

What response code indicates a successful SIP request?

Answer: 200 OK

In SIP, response codes are used to indicate the status of a request. A 200 OK response code specifically signifies that the request was successfully received, understood, and accepted. For instance, it confirms that a call invitation has been accepted.

Which SIP message is used to end a call?

Answer: BYE

The BYE message is a SIP method explicitly designed to terminate an established call or session. When a user hangs up, a BYE message is sent to the other party to gracefully end the communication session.

What is the purpose of the SIP REGISTER message?

Answer: To log a user's location with the server

The SIP REGISTER message is used by a user agent to inform a SIP registrar server of its current location and contact information. This allows the server to accurately route incoming calls or messages to the correct user agent, enabling reachability.

Which component in a SIP network manages user registration and call setup?

Answer: SIP proxy server

A SIP proxy server is a central component in a SIP network that manages user registration and call setup. It acts as an intermediary, routing SIP messages between user agents, enforcing policies, and facilitating the establishment of communication sessions.

What does SIP use to describe media capabilities?

Answer: SDP

SIP utilizes the Session Description Protocol (SDP) to describe the media capabilities and parameters for a communication session. SDP specifies details like the type of media (audio, video), codecs, and transport addresses, allowing participants to agree on how to exchange media.

Which method is used by SIP to maintain session signaling?

Answer: OPTIONS

The SIP OPTIONS method is primarily used to query a server or user agent about its capabilities or to check its availability without establishing a full session. It can also serve as a keep-alive mechanism to maintain session signaling and ensure the communication path remains active.