1. Reading Exercise (Routing) Policy-Mechanism Separation: PCE, ForCES
Special Topic: Software Defined Networks
Rudra Dutta
Computer Science, NCSU

2. Policy and Mechanism Mechanism provides “use”-ability
Defines what is primary use of device
Settings provide necessary parameters for mechanism
Policy changes “behavior” within the limits of identity
Implication: Mechanism restricts the possible policies
More correctly, mechanism interfaces
May make only one policy effectively possible
“Baked in” policy
Separation of policy from mechanism only makes sense when mechanism admits of multiple policies
Assumed implication: policy separation only makes sense for “enriched” forwarding boxes  but not necessarily
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

3. Benefit of Separation
Are there any benefits to separating policy if forwarding is not enriched
Say, remains destination-only
For that matter, what is separation?
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

4. IP-OSPF OSPF OSPF OSPF OSPF OSPF OSPF OSPF Control Control Control
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

5. Policy Separation (Routing)Policy/Mgmt/Knowledge
Control
Control
Control
(Routing)Policy/Mgmt/Knowledge
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

6. Automated Policy Computation
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

7. Distributed Automated Policy Computation
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Control
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

8. PCE (RFCs 4655, 5440) Read Abstract Read Introduction and Terminology
What is PCC and PCE?
What are the two types of communication mentioned?
Are they standardized?
Mandatory / optional ?
Copyright Rudra Dutta, CSC, NCSU, Spring 2017

9. ForCES (3654, 3746, 5810, 5812) Best start with requirements document
Same or different world-view as PCE?
Same or different results achieved?
Copyright Rudra Dutta, CSC, NCSU, Spring 2017