SSCA SDP Protocol 2

Question 1

Which SDP field specifies the network type and address type for the connection?

Accepted Answer

c= field

Answer

The c= (connection) field specifies the network type (e.g., IN), address type (e.g., IP4 or IP6), and connection address.

Question 2

In SDP, what does the 'a=sendonly' attribute indicate?

Accepted Answer

The endpoint will only send media and not receive

Answer

The 'a=sendonly' attribute indicates the endpoint intends to send media but not receive it in that direction.

Question 3

Which SDP line is mandatory in every SDP session description?

Accepted Answer

v= (protocol version)

Answer

The v= line indicating the SDP protocol version (always '0') is mandatory in every SDP session description.

Question 4

In SDP, what is the purpose of the 'a=rtpmap' attribute?

Accepted Answer

Maps RTP payload type numbers to codec names and clock rates

Answer

The a=rtpmap attribute maps dynamic RTP payload type numbers to encoding names, clock rates, and optional encoding parameters.

Question 5

What SDP attribute is used to indicate support for DTMF telephone events over RTP?

Accepted Answer

a=rtpmap with telephone-event

Answer

DTMF events are carried using RTP payload type 101 (or another dynamic type) with 'a=rtpmap:101 telephone-event/8000'.

(SSCA) Sip School Certified Associate Practice Test