SSCA Security, QoS & Regulatory Compliance 2

Question 1

Which SIP security mechanism uses a challenge-response scheme based on MD5 to authenticate users?

Accepted Answer

Digest Authentication

Answer

SIP Digest Authentication (RFC 3261) uses an MD5-based challenge-response mechanism where the server issues a nonce and the client responds with a hashed credential.

Question 2

A SIP proxy receives a REGISTER request from a user. Which response code does it send to initiate Digest Authentication?

Accepted Answer

401 Unauthorized

Answer

A registrar or UAS sends 401 Unauthorized with a WWW-Authenticate header to challenge a REGISTER request, prompting the client to resend with credentials.

Question 3

Which DSCP value is the IETF-recommended marking for interactive voice traffic to achieve Expedited Forwarding (EF) per-hop behavior?

Accepted Answer

DSCP 46 (EF)

Answer

DSCP 46 maps to the Expedited Forwarding (EF) PHB, which provides low latency and low jitter treatment required for real-time voice.

Question 4

CALEA requires US telecommunications carriers to do which of the following?

Accepted Answer

Provide lawful intercept capability to authorized agencies

Answer

The Communications Assistance for Law Enforcement Act (CALEA) mandates that carriers build lawful intercept interfaces so authorized law enforcement can access communications.

Question 5

Which attack involves an adversary flooding a SIP server with spoofed REGISTER messages to exhaust memory or processing resources?

Accepted Answer

REGISTER flood

Answer

A REGISTER flood attack sends large volumes of REGISTER requests—often with spoofed source IPs—to exhaust server resources and cause a denial of service.

(SSCA) Sip School Certified Associate Practice Test

(SSCA) Sip School Certified Associate Practice Test

SSCA Security, QoS & Regulatory Compliance 2