NORTH CAROLINA VOIP TECHNICIAN CERTIFICATION – PRACTICE QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
CORE DOMAINS
- VoIP Architecture and Protocols (SIP, H.323, MGCP, RTP)- Network Infrastructure and Quality of
Service (QoS, VLANs, PoE)- Codecs and Audio Signaling (G.711, G.729, Bandwidth Calculation)-
Security, Firewalls, and Session Border Controllers (SBCs)- Troubleshooting, Packet Analysis, and
Metrics (Jitter, Latency, Packet Loss)- Regulatory Compliance, E911, and Professional Ethics
INTRODUCTION
The North Carolina VoIP Technician Certification practice exam is engineered to evaluate the core
competencies required to design, deploy, manage, and troubleshoot Voice over Internet Protocol
solutions within enterprise and public sector networks. This comprehensive assessment validates
technical proficiency across network infrastructure readiness, protocol analysis, signaling security, and
quality enforcement. Comprising multiple-choice and complex, scenario-based questions, the exam
emphasizes real-world application, critical thinking, and decisive troubleshooting pathways. Candidates
are assessed on their understanding of industry-standard protocols, North Carolina E911 statutory
mandates, and the optimization of voice traffic under constrained network conditions, ensuring
operational excellence and infrastructure reliability.
SECTION ONE: QUESTIONS 1–100
What is the primary function of the Session Initiation Protocol (SIP) in a Voice over IP network
implementation?
A. To encapsulate and deliver real-time audio and video media streams across IP networks.
B. To establish, modify, and terminate multimedia communication sessions between endpoints.
C. To reserve network bandwidth along a specific path to guarantee a baseline Quality of Service.
D. To dynamically assign IP addresses and configuration parameters to VoIP endpoints upon boot.
🟢 B. To establish, modify, and terminate multimedia communication sessions between endpoints.
,🔴 RATIONALE: SIP is an application-layer signaling protocol defined by the IETF in RFC 3261. Its sole
responsibility is the setup, management, and teardown of sessions; it does not carry the actual voice
payload.
A technician is configuring an Ethernet switch port for a new enterprise VoIP deployment. Which feature
should be enabled to allow an IP phone and a colocated workstation to share a single physical port while
isolating voice traffic?
A. Link Aggregation Control Protocol (LACP)
B. Port Fast
C. Voice VLAN
D. Dynamic Host Configuration Protocol (DHCP) Snooping
🟢 C. Voice VLAN
🔴 RATIONALE: A Voice VLAN feature allows a single physical switch port to segment traffic into two
distinct broadcast domains: one for voice (usually tagged with an 802.1Q header) and one for data
(untagged), maximizing security and QoS isolation.
An enterprise network experiences dropped calls during peak utilization hours. Packet capture analysis
shows that voice packets are arriving out of order with highly variable delays. Which metric should the
technician analyze to resolve this specific behavior?
A. Jitter
B. Attenuation
C. Latency
D. Crosstalk
🟢 A. Jitter
🔴 RATIONALE: Jitter is defined as the variation in the delay of received packets. High jitter causes
packets to arrive out of sequence or too late for the de-jitter buffer to process, leading to audio artifacts
and dropped calls.
,Which codec provides toll-quality audio while consuming a nominal payload bit rate of 64 Kbps before
accounting for network overhead?
A. G.729
B. G.722
C. G.711
D. G.723
🟢 C. G.711
🔴 RATIONALE: G.711 is the standard pulse-code modulation (PCM) codec for digital telephony
operating at 64 Kbps. G.729 uses compression to achieve 8 Kbps, and G.722 is a wideband codec
operating at 64 Kbps but with higher audio fidelity.
Under North Carolina administrative rules and public safety mandates, what is an absolute requirement
for multi-line telephone systems (MLTS) deployed in enterprise environments regarding emergency E911
calling?
A. Emergency calls must be routed through an out-of-state centralized corporate proxy.
B. The system must provide a precise Dispatchable Location to the Public Safety Answering Point
(PSAP).
C. Users must dial a prefix such as '9' before the system connects to the emergency 911 operator.
D. All outbound emergency calls must be converted to low-bandwidth compressed G.729 audio streams.
🟢 B. The system must provide a precise Dispatchable Location to the Public Safety Answering Point
(PSAP).
🔴 RATIONALE: Federal and state regulations require MLTS deployments to deliver a dispatchable
location (including building, floor, or suite number) to ensure emergency responders can rapidly locate a
caller within a large facility.
A network engineer needs to protect an internal corporate SIP infrastructure from external Denial of
Service (DoS) attacks, protocol abnormalities, and unauthorized registration attempts. Which device is
best suited for this role at the network edge?
, A. Layer 2 Managed Switch
B. Session Border Controller (SBC)
C. Core Router
D. Hardware Security Module (HSM)
🟢 B. Session Border Controller (SBC)
🔴 RATIONALE: An SBC acts as a specialized firewall for VoIP traffic, performing deep packet
inspection of signaling (SIP) and media (RTP), hiding internal topologies, and mitigating signaling-based
attacks at the network boundary.
Which protocol is responsible for the actual transmission and encapsulation of real-time audio and video
payloads across an IP network?
A. SIP
B. RSVP
C. RTP
D. RTCP
🟢 C. RTP
🔴 RATIONALE: The Real-time Transport Protocol (RTP) provides end-to-end network transport
functions suitable for applications transmitting real-time data, such as audio, video, or simulation data,
over multicast or unicast network services.
When configuring Quality of Service (QoS) on a router for voice traffic, which Differentiated Services
Code Point (DSCP) value is standard for prioritizing real-time voice media streams?
A. CS3
B. AF41
C. EF
D. AF11
🟢 C. EF
ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026 Q&A | INSTANT DOWNLOAD PDF.
CORE DOMAINS
- VoIP Architecture and Protocols (SIP, H.323, MGCP, RTP)- Network Infrastructure and Quality of
Service (QoS, VLANs, PoE)- Codecs and Audio Signaling (G.711, G.729, Bandwidth Calculation)-
Security, Firewalls, and Session Border Controllers (SBCs)- Troubleshooting, Packet Analysis, and
Metrics (Jitter, Latency, Packet Loss)- Regulatory Compliance, E911, and Professional Ethics
INTRODUCTION
The North Carolina VoIP Technician Certification practice exam is engineered to evaluate the core
competencies required to design, deploy, manage, and troubleshoot Voice over Internet Protocol
solutions within enterprise and public sector networks. This comprehensive assessment validates
technical proficiency across network infrastructure readiness, protocol analysis, signaling security, and
quality enforcement. Comprising multiple-choice and complex, scenario-based questions, the exam
emphasizes real-world application, critical thinking, and decisive troubleshooting pathways. Candidates
are assessed on their understanding of industry-standard protocols, North Carolina E911 statutory
mandates, and the optimization of voice traffic under constrained network conditions, ensuring
operational excellence and infrastructure reliability.
SECTION ONE: QUESTIONS 1–100
What is the primary function of the Session Initiation Protocol (SIP) in a Voice over IP network
implementation?
A. To encapsulate and deliver real-time audio and video media streams across IP networks.
B. To establish, modify, and terminate multimedia communication sessions between endpoints.
C. To reserve network bandwidth along a specific path to guarantee a baseline Quality of Service.
D. To dynamically assign IP addresses and configuration parameters to VoIP endpoints upon boot.
🟢 B. To establish, modify, and terminate multimedia communication sessions between endpoints.
,🔴 RATIONALE: SIP is an application-layer signaling protocol defined by the IETF in RFC 3261. Its sole
responsibility is the setup, management, and teardown of sessions; it does not carry the actual voice
payload.
A technician is configuring an Ethernet switch port for a new enterprise VoIP deployment. Which feature
should be enabled to allow an IP phone and a colocated workstation to share a single physical port while
isolating voice traffic?
A. Link Aggregation Control Protocol (LACP)
B. Port Fast
C. Voice VLAN
D. Dynamic Host Configuration Protocol (DHCP) Snooping
🟢 C. Voice VLAN
🔴 RATIONALE: A Voice VLAN feature allows a single physical switch port to segment traffic into two
distinct broadcast domains: one for voice (usually tagged with an 802.1Q header) and one for data
(untagged), maximizing security and QoS isolation.
An enterprise network experiences dropped calls during peak utilization hours. Packet capture analysis
shows that voice packets are arriving out of order with highly variable delays. Which metric should the
technician analyze to resolve this specific behavior?
A. Jitter
B. Attenuation
C. Latency
D. Crosstalk
🟢 A. Jitter
🔴 RATIONALE: Jitter is defined as the variation in the delay of received packets. High jitter causes
packets to arrive out of sequence or too late for the de-jitter buffer to process, leading to audio artifacts
and dropped calls.
,Which codec provides toll-quality audio while consuming a nominal payload bit rate of 64 Kbps before
accounting for network overhead?
A. G.729
B. G.722
C. G.711
D. G.723
🟢 C. G.711
🔴 RATIONALE: G.711 is the standard pulse-code modulation (PCM) codec for digital telephony
operating at 64 Kbps. G.729 uses compression to achieve 8 Kbps, and G.722 is a wideband codec
operating at 64 Kbps but with higher audio fidelity.
Under North Carolina administrative rules and public safety mandates, what is an absolute requirement
for multi-line telephone systems (MLTS) deployed in enterprise environments regarding emergency E911
calling?
A. Emergency calls must be routed through an out-of-state centralized corporate proxy.
B. The system must provide a precise Dispatchable Location to the Public Safety Answering Point
(PSAP).
C. Users must dial a prefix such as '9' before the system connects to the emergency 911 operator.
D. All outbound emergency calls must be converted to low-bandwidth compressed G.729 audio streams.
🟢 B. The system must provide a precise Dispatchable Location to the Public Safety Answering Point
(PSAP).
🔴 RATIONALE: Federal and state regulations require MLTS deployments to deliver a dispatchable
location (including building, floor, or suite number) to ensure emergency responders can rapidly locate a
caller within a large facility.
A network engineer needs to protect an internal corporate SIP infrastructure from external Denial of
Service (DoS) attacks, protocol abnormalities, and unauthorized registration attempts. Which device is
best suited for this role at the network edge?
, A. Layer 2 Managed Switch
B. Session Border Controller (SBC)
C. Core Router
D. Hardware Security Module (HSM)
🟢 B. Session Border Controller (SBC)
🔴 RATIONALE: An SBC acts as a specialized firewall for VoIP traffic, performing deep packet
inspection of signaling (SIP) and media (RTP), hiding internal topologies, and mitigating signaling-based
attacks at the network boundary.
Which protocol is responsible for the actual transmission and encapsulation of real-time audio and video
payloads across an IP network?
A. SIP
B. RSVP
C. RTP
D. RTCP
🟢 C. RTP
🔴 RATIONALE: The Real-time Transport Protocol (RTP) provides end-to-end network transport
functions suitable for applications transmitting real-time data, such as audio, video, or simulation data,
over multicast or unicast network services.
When configuring Quality of Service (QoS) on a router for voice traffic, which Differentiated Services
Code Point (DSCP) value is standard for prioritizing real-time voice media streams?
A. CS3
B. AF41
C. EF
D. AF11
🟢 C. EF
