Describe the three perspectives of the SDN landscape.
Device perspective, control perspective, and application perspective.
Describe the responsibility of each layer in the SDN layer perspective.
Applications define policies; controller translates policies into rules; infrastructure (switches) executes forwarding.
Describe a pipeline of flow tables in OpenFlow.
- Matching rule
- Actions to be executed on matching packets
- Counters for stats
What’s the main purpose of southbound interfaces?
To allow controllers to communicate with and manage forwarding devices.
What are three information sources provided by the OpenFlow protocol?
Switch capabilities, statistics, and events (e.g., packet-in messages).
What are the core functions of an SDN controller?
- topology
- statistics
- notifications
- device management
- shortest path forwarding
- security mechanisms
What are the differences between centralized and distributed architectures of SDN controllers?
Centralized controllers run on a single node; distributed controllers run across multiple coordinated nodes for scalability and resilience.
When would a distributed controller be preferred to a centralized controller?
When scalability, fault tolerance, or low-latency regional control is required.
Describe the purpose of each component of ONOS.
- Titan graph database and Cassandra distributed key-value store implement view
- Blueprints graph API for network view
- Zookeeper maintains mastership between switch and controllers
How does ONOS achieve fault tolerance?
By using controller clustering, state replication, and leader election.
What is P4?
A programming language for specifying packet-processing behavior on network devices.
What are the primary goals of P4?
- Reconfigurability
- Protocol independence
- Target independence
What are the two main operations of the P4 forwarding model?
- Configure: program the parser
- Populate: match+action tables
What are the applications of SDN? Provide examples.
Traffic engineering (load balancing), network virtualization (slicing), security (firewalling, DDoS mitigation), and data center automation.
Which BGP limitations can be addressed by using SDN?
Limited policy expressiveness, slow convergence, and coarse-grained control.
What’s the purpose of SDX?
To enable flexible, fine-grained interdomain routing policies at exchange points using SDN.
Describe the SDX architecture.
- Each AS has illusion of its own virtual SDN switch connected to every other
- Independent forwarding policy definitions
- Uses Pyretic language
What are the applications of SDX in wide-area traffic delivery?
- Application specific peering
- Traffic engineering
- Traffic load balancing
- Traffic redirection through middleboxes
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Module 1: Quiz10
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Module 1: Practice Quiz5
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Module 2: Quiz21
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Module 2: Practice Quiz4
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Module 3: Quiz21
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Module 3: Practice Quiz14
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Module 4: Quiz23
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Module 4: Practice Quiz21
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Module 5: Quiz13
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Module 5: Practice Quiz27
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Module 6: Quiz10
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Module 7: Practice Quiz18
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Module 7: Quiz13
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Module 8: Practice Quiz33
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Module 8: Quiz21
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Module 9: Practice Quiz24
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Module 9: Quiz16
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Module 10: Practice Quiz13
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Module 10: Quiz14
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Module 11: Practice Quiz25
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Module 11: Quiz15
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Module 12: Quiz12
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Module 7: AI11
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Module 8: AI18
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Module 9: AI23
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Module 10: AI23
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Module 11: AI28
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Module 12: AI24
