CS6250 COMPUTER NETWORKS EXAM 1
ACTUAL EXAM SCRIPT EXPERT CERTIFIED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
⩥ Why would equipment diversity cause complexity when managing a
network?
Answer: Different software must be used for different protocols (7)
⩥ Why do proprietary technologies cause complexity when managing
networks?
Answer: Some equipment (router, switch, etc.) run on closed/proprietary
software
Configuration interfaces vary as a result.
This causes issues for managing devices centrally. (7)
⩥ What is the simple idea of SDN that helps make networks more
manageable?
Answer: Separate tasks into control plane and data plane. (7)
,⩥ What are the 3 phases of history of SDN?
Answer: 1. Active networks
2. control plane and data plane separation
3. OpenFlow API and network operating systems (7)
⩥ What led to the growth of active networks, and what is their goal?
Answer: 1. the tediousness of standardizing new protocols
2. goal is to open up network control with an API that exposes resources
and supports *customization of functionalities* for subsets of packets
passing through network nodes
(7)
⩥ Why do active networks conflict with idea of E2E?
Answer: They require customization at network nodes (not simplicity at
network core)
(7)
⩥ What were the two types of programming models in active
networking? How are thy different?
,Answer: 1. Capsule model
- carries in band data packets
- most used in relation to active networking
- code distribution ACROSS networks
- data plane
2. Programmable router/switch model
- out of band mechanisms
- decision-making a job for the NETWORK OPERATOR
- Difference is where the code to execute at the nodes was carried (7)
⩥ What are 4 tech developments that encouraged active networking?
Answer: 1. reduction in computation cost (more processing can take
place in the network)
2. advancement in programming languages
3. advancement in rapid code compilation and formal methods
4. funding agencies promoted interoperability among projects
- necessary because there were no short-term use cases
, (7)
⩥ What are 4 problems that encouraged active networking?
Answer: 1. developing network services took a long time
2. third party interests to dynamically meeting needs of app and network
conditions
3. researches needed a network for large-scale experiments
4. disadvantage of diverse models and vendors meant a desire for unified
control over middleboxes (7)
⩥ What are 3 contributions of SDN?
Answer: 1. programmable functions in network = lower barrier to
innovation
2. network virtualization and ability to demultiplex based on packet
headers
3. vision of unified architecture for middlebox orchestration
ACTUAL EXAM SCRIPT EXPERT CERTIFIED
QUESTIONS AND CORRECT ANSWERS
GRADED A+
⩥ Why would equipment diversity cause complexity when managing a
network?
Answer: Different software must be used for different protocols (7)
⩥ Why do proprietary technologies cause complexity when managing
networks?
Answer: Some equipment (router, switch, etc.) run on closed/proprietary
software
Configuration interfaces vary as a result.
This causes issues for managing devices centrally. (7)
⩥ What is the simple idea of SDN that helps make networks more
manageable?
Answer: Separate tasks into control plane and data plane. (7)
,⩥ What are the 3 phases of history of SDN?
Answer: 1. Active networks
2. control plane and data plane separation
3. OpenFlow API and network operating systems (7)
⩥ What led to the growth of active networks, and what is their goal?
Answer: 1. the tediousness of standardizing new protocols
2. goal is to open up network control with an API that exposes resources
and supports *customization of functionalities* for subsets of packets
passing through network nodes
(7)
⩥ Why do active networks conflict with idea of E2E?
Answer: They require customization at network nodes (not simplicity at
network core)
(7)
⩥ What were the two types of programming models in active
networking? How are thy different?
,Answer: 1. Capsule model
- carries in band data packets
- most used in relation to active networking
- code distribution ACROSS networks
- data plane
2. Programmable router/switch model
- out of band mechanisms
- decision-making a job for the NETWORK OPERATOR
- Difference is where the code to execute at the nodes was carried (7)
⩥ What are 4 tech developments that encouraged active networking?
Answer: 1. reduction in computation cost (more processing can take
place in the network)
2. advancement in programming languages
3. advancement in rapid code compilation and formal methods
4. funding agencies promoted interoperability among projects
- necessary because there were no short-term use cases
, (7)
⩥ What are 4 problems that encouraged active networking?
Answer: 1. developing network services took a long time
2. third party interests to dynamically meeting needs of app and network
conditions
3. researches needed a network for large-scale experiments
4. disadvantage of diverse models and vendors meant a desire for unified
control over middleboxes (7)
⩥ What are 3 contributions of SDN?
Answer: 1. programmable functions in network = lower barrier to
innovation
2. network virtualization and ability to demultiplex based on packet
headers
3. vision of unified architecture for middlebox orchestration
