Cisco ENCOR IP Services and QoS 1 — Questions and Answers
Question 1: Which QoS model provides per-flow resource reservation using RSVP signaling?
- Best Effort
- IntServ (Correct answer)
- DiffServ
- LLQ
Correct answer: IntServ
Integrated Services (IntServ) uses RSVP to reserve bandwidth and guarantee QoS on a per-flow basis end-to-end.
Question 2: What DSCP value corresponds to Expedited Forwarding (EF), commonly used for voice traffic?
- DSCP 10
- DSCP 26
- DSCP 46 (Correct answer)
- DSCP 48
Correct answer: DSCP 46
Expedited Forwarding (EF) is defined as DSCP 46 (binary 101110) and is used for delay-sensitive traffic like VoIP.
Question 3: Which NTP stratum level indicates the NTP server is directly connected to an authoritative time source?
- Stratum 0
- Stratum 1 (Correct answer)
- Stratum 2
- Stratum 15
Correct answer: Stratum 1
Stratum 1 NTP servers are directly synchronized to a Stratum 0 reference clock (e.g., GPS or atomic clock).
Question 4: What is the purpose of SNMP traps?
- Poll devices for MIB data
- Allow managers to set device configuration
- Send asynchronous event notifications from agent to manager (Correct answer)
- Authenticate SNMP community strings
Correct answer: Send asynchronous event notifications from agent to manager
SNMP traps are unsolicited notifications sent by an SNMP agent to the manager when a significant event occurs.
Question 5: Which NAT type maps one internal IP address to one unique external IP address on a one-to-one basis?
- Dynamic NAT
- PAT (NAT overload)
- Static NAT (Correct answer)
- Policy NAT
Correct answer: Static NAT
Static NAT creates a permanent one-to-one mapping between an inside local and inside global IP address.
Question 6: Which queuing mechanism guarantees minimum bandwidth and prioritizes delay-sensitive traffic using a strict priority queue?
- FIFO
- WFQ
- CBWFQ
- LLQ (Correct answer)
Correct answer: LLQ
Low Latency Queuing (LLQ) adds a strict priority queue to CBWFQ, ensuring voice and real-time traffic is always serviced first.
Cisco ENCOR IP Services and QoS 1
Which QoS model provides per-flow resource reservation using RSVP signaling?