QoS Interview Questions
  1.     What is difference b/w Layer2 and Layer3 QoS?
  2.     What is the basic difference b/w TCP and UPD traffic?
  3.     Define Jitter with an example.
  4.     What is difference b/w the clock-rate and bandwidth command configured on the WAN interfaces?
  5.     Name various types of Delays experienced while sending the traffic.
  6.     Name few Classification and marking tools used in QoS.
  7.     List various Queuing tools/methods used for QoS.
  8.     Also list few shaping, congestion avoidance, and link efficiency tools used for QoS.
  9.     Describe the QoS models IntServ and DiffServ.
  10.     What is meant by Per Hop Behavior(PHB) and DSCP in DiffServ QoS Model?
  11.     What is MQC with some example configurations and also list the advantages of MQC feature.
  12.     What is AutoQoS and its use?
  13.     Name the QoS field carried under 802.1Q Header, IP header, and MPLS header?
  14.     What is purpose of TX ring and TX queue on Cisco routers?
  15.     What is CBWFQ?
  16.     What is difference b/w Traffic Shaping and Traffic Policying with example.
  17.     Explain the terms Tc, Bc, Be, CIR, Access Rate.
  18.     Explain the concept of Token Buckets?
  19.     Explain the term TCP Starvation.
  20.     Define the congestion avoidance terms RED and WRED.
  21.     Explain the need of QoS in Layer 2 devices?