Cisco Auto QOS Interview Questions
| Question |
| Can you plese explain about QOS concept? |
| Answer |
| QoS is denoted for Quality of Service, where we can prioritize/restrict/delay the traffic flow for protocols/application. |
| Question |
| How we can provide Qos at the different Layer of TCP/IP. Please can you explain |
| Answer |
| QOS works at Layer 2 and Layer 3 in OSI. |
| Question |
| Advantages/pre-requisites of QOS ? |
| Answer |
| Some of the advantages are: 1) Prioritization of Voice and Video traffic. 2) Bandwidth Optimization for WAN links. 3) Smooth conversation for Business critical applications ETC.. |
| Question |
| What is the exact implication of AutoQos , how it works and i it only relevent to VOIP traffic of can be provisioned for any defined traffic |
| Answer |
| It can be used for Other traffic also. you can use NBAR ( Network based Application Recognition) for this. But It is widely used for Voice & Video traffic over the WAN links. |
| Question |
| What is class map, what is policy map and what is the difference? |
| Answer |
| A class map defines the traffic and the policy map creates a policy for the classes, with rules to follow. and Policy map are bind on interface to take effect. |
| Question |
| Could you please explain about the bandwidth calculation for the QoS Shapping? |
| Answer |
| Hi Bandwidth calculation for Shaping is based on the Bandwidth configured on Interface of device on which policy is mapped. |
| Question |
| What is the formula for Shape average calculation |
| Answer |
| Shape average :-> CIR = bc/tc. |
| Question |
| Is NBAR the default classification mechanism for AutoQOS, can we use PBR , COS or DSCP for classification for AutoQos , what is the default dispatch method of Auto QOS and the queing. |
| Answer |
| 1) Prerequisites is CEF must be enabled on each interface where AutoQoS is implemented, as NBAR is dependent on CEF. AutoQOS is required for less management task using automation of QoS based on NBAR collection. 2) COS and DSCP are also used with AutoQoS based on different predefined classes of AutoQOS. 3) LLQ is used with AutoQoS. |
| Question |
| How we can provide Qos for Highly congested network in Network Layer. Please explain |
| Answer |
| Currently this discussion is only for Cisco Auto QoS Feature. Please drop me a mail I will help you for the same. |
| Question |
| As by the word AutoQos, is the qos implementation based on predefined templates by cisco , suppose if have to implement qos for VOIP and defined only the match criteria , is it like it will automatically implement the best QOS for VOIP traffic ?? |
| Answer |
| Yes, you are right. But in future if you want to add/delete more criteria you can do the same. |
| Question |
| The Different QoS Capabilities of the VMware vSwitch |
| Answer |
| I may need some more information for VMvare vSwitch. Please drop me a mail, will discuss on that. |
| Question |
| What is the base for it as we already have multiple functionalites in Cisco QOS to implement based on the requirememnt and also enhenced flexibility. |
| Answer |
| Prerequisites and base of AutoQos is : 1) CEF must be supported/enabled. 2) NBAR. |
| Question |
| What is the Base IOS versions supports AutoQos ? |
| Answer |
| Cisco IOS 12.3 and above for full functionality of AutoQoS. |
| Question |
| How can we reserve b/w for video conferencing devices and IP phones explain ?. |
| Answer |
| Cisco AutoQOS reserve the bandwidth for Video and Voice based on the Auto discovery of protocol and Bandwidth configured on Interface. If you want to do manual you can use Class-map and Policy map for the same. |
