Computer Networks -CS6250 Exam 2
Questions and Answers
What are 4 problems that encouraged active networking? - ✔✔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? - ✔✔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
(7)
Which plane are active networks associated with? - ✔✔Data plane (7)
,What plane do programmable functions in active networks focus on
increasing programmability, and why? - ✔✔- Data plane
- isolate experimental traffic from normal traffic (7)
What were some downfalls of active networking? - ✔✔- it was too ambitions
- didn't emphasize performance and security
- it didn't solve any short term problems
- end users need to be ale to write in java (7)
Did active network do anything for performance? Security? - ✔✔No (7)
What challenge did control and data plane separation tackle? - ✔✔Challenging how
existing routers and switches tightly integrated the data and control plane (7)
What were 4 tech developments that paved the way for control and data plane separation? -
✔✔1. packet forwarding (data plane) was implemented in hardware (separate from
control plane)
2. ISPs couldn't meet increasing demands for greater reliability and new services b/c of
increasing scope and size
3. servers have much more memory and processing resources - routing decisions could be done
on one server for one ISP network
4. open-source routing lowers barrier to creating prototypes of centralized routing controllers
(7)
,How did higher link speeds in backbone networks encourage control and data plane
separation? - ✔✔packet forwarding implemented in hardware, separate from control
plane
(7)
What 2 innovations led to the control and data plane separation? - ✔✔1. open
interface between control and data plane
2. logically centralized control of network(7)
Was the network centrally controlled logically, physically, or both under control and data
plane separation? - ✔✔LOGICALLY centrally controlled(7)
What are 3 ways control plane and data plane separation differed form active networks? -
✔✔1. Spurred innovation for network ADMINS instead of users
2. emphasized programmability in CONTROL domain instead of data domain
3. worked towards NETWORK-WIDE visibility and control rather than device level
configurations(7)
Was visibility and control at network level or device level for active networks? Control/data
plane separation? - ✔✔Device level
Network level
(7)
Was programmability in control domain or data domain for active networks? Control/data
plane separation? - ✔✔Data domain
, control domain
(7)
Was innovation for network admins or users for active networks? Control/data
plane separation? - ✔✔Users
Admins
(7)
What are 5 use cases for control plane/data plane? - ✔✔1. path selection based on network
traffic load
2. minimized disruptions during planned routing changes
3. redirecting or dropping suspected attack traffic
4. allow customer networks more control over network flow
5. offer value added services for virtual private network customers
(7)
Were control plane and data plane separation efforts focused on managing routing
WITHIN ONE ISP? - ✔✔No
some wanted to enable flexible route control across many ASes
(7)
Questions and Answers
What are 4 problems that encouraged active networking? - ✔✔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? - ✔✔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
(7)
Which plane are active networks associated with? - ✔✔Data plane (7)
,What plane do programmable functions in active networks focus on
increasing programmability, and why? - ✔✔- Data plane
- isolate experimental traffic from normal traffic (7)
What were some downfalls of active networking? - ✔✔- it was too ambitions
- didn't emphasize performance and security
- it didn't solve any short term problems
- end users need to be ale to write in java (7)
Did active network do anything for performance? Security? - ✔✔No (7)
What challenge did control and data plane separation tackle? - ✔✔Challenging how
existing routers and switches tightly integrated the data and control plane (7)
What were 4 tech developments that paved the way for control and data plane separation? -
✔✔1. packet forwarding (data plane) was implemented in hardware (separate from
control plane)
2. ISPs couldn't meet increasing demands for greater reliability and new services b/c of
increasing scope and size
3. servers have much more memory and processing resources - routing decisions could be done
on one server for one ISP network
4. open-source routing lowers barrier to creating prototypes of centralized routing controllers
(7)
,How did higher link speeds in backbone networks encourage control and data plane
separation? - ✔✔packet forwarding implemented in hardware, separate from control
plane
(7)
What 2 innovations led to the control and data plane separation? - ✔✔1. open
interface between control and data plane
2. logically centralized control of network(7)
Was the network centrally controlled logically, physically, or both under control and data
plane separation? - ✔✔LOGICALLY centrally controlled(7)
What are 3 ways control plane and data plane separation differed form active networks? -
✔✔1. Spurred innovation for network ADMINS instead of users
2. emphasized programmability in CONTROL domain instead of data domain
3. worked towards NETWORK-WIDE visibility and control rather than device level
configurations(7)
Was visibility and control at network level or device level for active networks? Control/data
plane separation? - ✔✔Device level
Network level
(7)
Was programmability in control domain or data domain for active networks? Control/data
plane separation? - ✔✔Data domain
, control domain
(7)
Was innovation for network admins or users for active networks? Control/data
plane separation? - ✔✔Users
Admins
(7)
What are 5 use cases for control plane/data plane? - ✔✔1. path selection based on network
traffic load
2. minimized disruptions during planned routing changes
3. redirecting or dropping suspected attack traffic
4. allow customer networks more control over network flow
5. offer value added services for virtual private network customers
(7)
Were control plane and data plane separation efforts focused on managing routing
WITHIN ONE ISP? - ✔✔No
some wanted to enable flexible route control across many ASes
(7)
