SSCA VoIP Architecture 5

Question 1

What is the purpose of a TURN server in VoIP NAT traversal?

Accepted Answer

To relay media through the server when direct or server-reflexive connectivity fails

Answer

TURN (Traversal Using Relays around NAT) relays media packets through the TURN server when direct NAT traversal methods cannot establish a path.

Question 2

Which VoIP signaling protocol uses a master/slave model where a call agent controls dumb endpoints called Media Termination Points?

Accepted Answer

MGCP

Answer

MGCP (Media Gateway Control Protocol) uses a centralized call agent (controller) that issues commands to endpoint devices (Media Termination Points).

Question 3

In VoIP, what does 'early media' refer to?

Accepted Answer

Audio or video played before a call is answered, such as ringback tone or announcements

Answer

Early media is audio or video transmitted in the 180/183 provisional response stage before the called party answers the call.

Question 4

What VoIP architecture element provides features like music-on-hold, conferencing, and IVR by manipulating the media plane?

Accepted Answer

Media Resource Function (MRF)

Answer

A Media Resource Function (MRF) processes and mixes media streams to provide conferencing, announcements, IVR, and other media-related services.

Question 5

What is 'SIP forking' and what two types exist?

Accepted Answer

Sending an INVITE to multiple destinations; parallel (simultaneous) and sequential (one at a time)

Answer

SIP forking allows a proxy to forward an INVITE to multiple destinations simultaneously (parallel) or one after another (sequential) to find the called party.

(SSCA) Sip School Certified Associate Practice Test

(SSCA) Sip School Certified Associate Practice Test

SSCA VoIP Architecture 5