Download 4. SUPA Declarative Model

SUPA Declarative Policy
Jun Bi
Tsinghua Univ./CERNET
draft-bi-declarative-policy-00
Goal
 The goal, objective, high level request
 Express what should be done without telling how
From A to B,
and I have $$
budget….
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Declarative Policy
 Policy
 Defines how policy rules are used to manage service
behavior
 Policy Model
 Defines rules for governing managed objects
 Defines representation for rules
 Can be used to govern service relationships
 Declarative Policy
 More abstracted
 More service level
 Device independent
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Types of Policy (1)
 Event-Condition-Action (ECA)
 IF the Event is TRUE
 IF the Condition is TRUE
o THEN execute the Actions
 Explicit programming of which condition and which
action to be chosen (rationality is in the policy!)
Event manager
network
event
time/date
service flow
Context manager
ECA
E
E
E
A
Action
manager
A
Ct
A
Ct
Ct
user attribute
flow info
network status
to controller/device
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Types of Policy (2)
 Declarative （Goal）
 Express what should be done, not how to do it
 Specifies criteria for choosing a set of states, any of
which is acceptable
 Rationality is generated by optimizer/planner
multiconstraint
G
Context manager
Ct
multi
constraint
solver
Ct
Ct
user attribute
flow info
path info
Action manager
A
A
A
A
A
A
to controller/device
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Declarative Description
 Only describe the constraints on possible state
 No information of how to do to achieve the state
Goal
Objects
Constraints
Declarative
Description
Multiconstraint
solver
Existing
service model
S1
S2
Action1;
Action2;
…
S3
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Seven Bridges of Königsberg
The problem was to devise a walk Programming：manually decompose logic an objects,
through the city that would cross permutation and combination.(complicate, rely on
each bridge once and only once
human knowledge and modeling)
Its negative resolution by
Leonhard Euler in 1736 laid
the foundations of graph
theory and prefigured the idea
of topology
Declarative: only describe objects and logic constraint
What is land
What is a bridge
How the 7
bridges are
connected
Too easy for me…..
What is a
path
Constraint on path: no
path can be used twice
Output, no solution
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Policy in Network Management
 The usage of policy rules to manage the behavior of managed entities
 Policy is about governance, and can be expressed differently:
More
Abstract
 Goal: No threshold will be violated in a set of link (link A, B and C)
 ECA: When this threshold of link A is violated, redirect the flow 1 to link B
More
Concrete
Service Manager
Policy
Data Model
…
Service
Data Model
GoalPolicyi
RESTCONF /
NETCONF
Network Manager (Controller)
Network Manager (Controller)
Topology Data Model
Topology Data Model
Network Elements
Network Elements
(routers, switches, etc)
(routers, switches, etc)
ECAPolicyp
ECAPolicyq
ECAPolicyr
…
GoalPolicyj
ECAPolicy1
…
…
GoalPolicy1
ECAPolicyx
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SUPA Policy Engine Demo
External
interface /
declarative API
SUPA
Events
declarative-policy{
var {a:path; b:path;}
expr { a.delay<500 &&
Goal Policy API
b.delay<500 &&
(Constraint, Policy parameter) a.links&b.links ==EMPTY;}}
Predefined
Policy
Core Engine
Conditions
declar
ative
ECA
ECA
User-Defined Policy
Actions
1
Define policy use standard policy
RESTful API
XML Data
interface. Express declarative
without knowing network details.
Traffic
collector
Controller
Constraint Solving
The SUPA policy engine solves
the multiple constraints and
2
service requests.
Policy Enforcement
Output a solution and enforce the
policy to network infrastructures
with actions.
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There will be a SUPA Policy Engine Demo at BnB on
Thursday evening. Welcome to join us.
Questions?
Questions?
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