A M

anagement A

rchitecturefor A

ctive Netw

orks

A. Barone, P. Chirco, G

. Di Fatta, G

. Lo Re

AM

S2002, Active M

iddleware Service

Edinburgh (UK

), 23 July 2002(Stars, M

. C. Escher)

ICA

R-C

NR

Istituto di Calcolo e Reti ad Alte prestazioni

(CERE-CNR, CEntro di studio sulle Reti di Elaboratori)

Consiglio Nazionale delle Ricerche (Palerm

o, Italy)

G. D

i Fatta, Computer N

etworks G

roup, ICAR-CN

R2

Overview

•N

etwork M

anagement

–SN

MP fram

ework

–A

ctive Netw

orks for Netw

ork Managem

ent

•A

ctive Netw

orks Managem

ent–

Active M

IB and Active Local A

gent–

Active Routers Testbed and A

Ngate

•M

anager and Monitor tools

•N

etwork Events M

ining•

Conclusions

G. D

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R3

Netw

ork Managem

ent•

Managing Entity

•M

anaged Device

–Local A

gent–

MIB (M

anagement

Information Base)

•SN

MP (Sim

ple Netw

orkM

anagement Protocol)

Managing E

ntity

Managed D

eviceM

anaged Device

Managed D

eviceM

anaged Device

Netw

orkM

anagement

Protocol

¸centralized approach: polling¸

active local agent role: simple traps

¸issues: scalability and efficiency

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R4

Active N

etworks for N

etwork M

anagement

Active N

etworks benefits for N

etwork M

anagement are:

• availability of information in interm

ediate nodes

• data processing along the path

• distributed, cooperative, autonomous strategies

(e.g., SmartPackets)

Active N

etworks M

anagement

AN

allow and prom

ote the fast and dynamic introduction of new

servicesand applications. A

ctive Applications are difficult to be debugged and

monitored.

Active N

etworks require a m

ore efficient approach for network and

applications managem

ent.

G. D

i Fatta, Computer N

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Active Routers Testbed (A

RT)

Aim

s of the AR

T project:•

testing new netw

ork services and protocols•

developing new active applications

•netw

ork resource optimisation

40 Active N

odes• Static Topology Configuration (80 peer-to-peer links)

• Dynam

ic Topology Configuration (240port ethernet sw

itch with m

anagement)

A 40 nodes cluster at ICA

R-CNR to study and test A

ctive Netw

orks

AR

T is a hardware platform

which prototypes a

network com

putational environment according to

the Active N

etworks paradigm

.

Practical need for an Active

Managem

ent Architecture

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R6

AN

Managem

ent Framew

orkM

anagement A

pplication Interface

GU

I

XM

Lw

rapper

request[X

ML

]

response [XM

L]

Active N

etwork

EE

EE

EE

EE

EE

ALA

ALA

ALA

ALA

ALA

The Active Local A

gent ( ) is anactive

service of

the EE

which

provides the managem

ent API.

ALA

AN

Access P

oint

XM

L parser

EE

interface

active packets[M

L, Java, …

]

reports

AN

gateway

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i Fatta, Computer N

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R7

Active Local A

gent ( )

AM

IB Objects are variables of A

ctive Applications. A

As can explicitly

submit data to A

LA and associate Filters w

ith data.

A Filter is a test executed w

hen the data value changes. An Event is raised if

the test succeeds.

An A

ction is a capsule associated with an Event and it is released w

hen thatEvent is raised. Events have a local scope and a default A

ction is defined tosim

ply report the Event.

<Filter1, Event1>...<Filter-k, Event-k>

Dataset_data

new value

raise local events

ALA

is a SNM

P-like managem

ent agent which exploits A

N advantages: it

provides the

API

for an

object-oriented A

ctive M

IB and

it is

programm

able according to a Filter-Event-Action m

odel.

AM

IB Object

execute actions

ALA

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R8

ALA

Architecture

ActiveMIB

Get/Setdata, filters,actions

ActionsScheduler

SyncEvents

Generator

Easync

Esync

ActionPerformer

NTP

ActivePacket

<Event,Action>

AgentInterfaceand PolicyEnforcement

ALA - Active Local Agent

Action result:- ActivePacket- RemoteReport- Local/RemoteSet/Get data,filters,actions

Clock andsync process

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AN

gatewayExam

plesIm

plementation

Services

setVarV

alue, getVarV

alue,getA

ppList, setFilterTest,… getTopology, ping,delivery_Path,delivery_Tree, …

setTopology,bootstrap_A

N,

shutdown_A

N, …

ALA

as PLAN

service(O

Caml)

AA

-leveladm

inistrativeand public

packet-level (PLAN

)A

N-level

public

UN

IX Shell scripts

AN

-leveladm

inistrative

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R10

AN

gate - the Active N

etwork gatew

ay

• gateway server selection

• EE selection (only PLAN

is supported in v1.0b6)

• user authentication (user, administrator)

• AN

Manager m

odule

• AA

Monitor m

odule

http://angate.cere.pa.cnr.it

username: guest

password: guest

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Active N

etworks M

anager

• Topology editor

• PLAN

et configuration and setup (only admin)

• Topology discovery

• Link and node status

• Capsule injection with

navigation patterns¸

node¸

path¸

star¸

tree

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Navigation Pattern: D

elivery_MST

23

14

05 6

78

9

Forw

ard Path

Backw

ard Path

injection node

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R13

Active A

pplications Monitor

• ALA

services GU

I

• AN

ode/AA

/AM

IB-data tree

• AA

tracing and debugging and perform

ance measurem

ents

• Message area for reports

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R14

New

Applications

Managem

entA

pplication

GU

I

XM

Lw

rapper

AN

Access P

oint

Active N

etwork

XM

L parser

EE

Interface

active packets[M

L, Java, …

]reports

EE

EE

EE E

E

EE

AN

gateway

Managem

entA

pplication

GU

I

XM

Lw

rapper

Netw

ork EventsM

iningL

ogicE

ngineX

ML

wrapper

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R15

Netw

ork Events Mining (N

EM)

NEM

systems deals w

ith large archives of events gathered fromthe netw

ork devices to extract useful information.

Typical NEM

goals are:• the diagnose of root causes of netw

ork faults and performance

degradations by establishing relationships between netw

ork events;• filtering event (alarm

) flood by correlating several events into asingle conceptual event.

NEM

systems should provide correctness and optim

ality.

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NEM

Application

The Logical Managing Entity is based on the Situation C

alculus,w

hich is a dialect of the First Order Logic and allow

s them

odeling of dynamic system

s. It is implem

ented by the Golog

logic programm

ing language.

Netw

ork Events Mining

Logic

Engine

XM

Lw

rapper

XM

L request/responseto/from

AN

Situation Calculus• entities• events• actions• situations• predicates• fluents

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The Logical System D

esign

1. O

ntological engineering process providesß

effective structured representation of all the network

entities, events and actions.(fi

predicates, fluents, actions, preconditions)

2. Logical axiom

atization of relationships among the

network events are to be defined.

ßThe occurrence of an action a m

akes the system m

ovefrom

a given situation si to the consequent situation si+1.(fi

successor state axioms)

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Ontological A

nalysis

Logical entities and relationships are expressed as Predicatesand Fluents.

Predicates:ß iface(I)

ß address(I, <string>)

ß node(N)

ß flag_node(N)

ß ala(A)

ß ala_location(A, N)

ß link(L)

ß connect(L, I1, I2) where link(L), iface(I1), iface(I2)

ß belongs(I, N)

· · ·

connect(L, I1, I2)

where link(L),

iface(I1), iface(I2)

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Fluents

In situation s the flag of node N is on\off.

node_flag_status(N, on\off, s)

In situation s node N is on\off.

node_status(N, on\off,

s)

In situation s the Active Local Agent A is

on\off.

ala_status(A, on\off,

s)

In situation s interface I is on\off.

iface_status(I, on\off,

s)

In situation s nodes A and B are connected at

network layer by path L.

path(A, B, L,

s)

In situation s nodes N1 and N2 are directly

connected at network layer.

neighbour(N1, N2,

s)

In situation s <arrayTable> is the routing

table of node N.

routing_table(N,<arrayTable>,s)

In situation s the physical link L is on\off.

link_status(L, on\off,

s)In situation s nodes A

and B are

connected at network layer by

path L.path(A, B,

L, s)

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Primitive A

ctions

...

...

The semaphore of the routing table in the router R is

switched off.

Turn_flag_off(R)

Router R forwards a packet P according to its current

routing table T.

Forward(R, P, T)

Router R executes a Shortest Path Tree algorithm to

determine the shortest paths table T toward all the

destinations.

SPT_execute(R, T)

Router R stores a routing table change (this will allow

to trace back the events).

Update_store(R, entry)

Router R receives a topology change from a neighbour

(the semaphore of the routing table is switched on).

Update_receive(R, upd)

Router R sends a topology change to all its neighbours.

Update_send(R, upd)

The network link L is set down (the semaphore of both

the connected routers is switched on).

Link_down(L)

The network link L is set up (the semaphore is switched

on in both the connected routers).

Link_up(L)

Router R stores a routing table change(this allows to trace back events).

Update_store(R, entry)

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R21

Primitive A

ction Preconditionsß Poss

(Link_up(L), s)

≡ link_status(L, off, s).

ß Poss(Link_down(L), s)

≡ link_status(L, on, s).

ß Poss(Update_send(R, upd), s)

≡ node_flag_status(R, on, s).

ß Poss(SPT_execute(R, T), s)

≡ node_flag_status(R, on, s).

ß Poss(Forward(R, PCK, T), s)

≡ Destination(PCK) = D

Ÿ Routing_entry(T,D,s) = I

Ÿ iface_status(I,on,s).

ß Poss(Turn_flag_off(R), s)

≡ node_flag_status(R, on, s).

· · ·

Successor State Axiom

sß neighbour(N1,N2,do

(a,s))

≡ neighbour(N1,N2,s)

Ÿ connect(L,I1,I2)

Ÿ belongs(I1,N1)

Ÿ belongs(I2,N2)

Ÿ a

≠ Link_down(L).

ß node_flag_status(N, on, do

(a, s))

≡ node_flag_status(N, on, s)

Ÿ a

≠ Turn_flag_off(N).

· · ·

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i Fatta, Computer N

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roup, ICAR-CN

R22

NEM

goals

:- path(node1, node2, X, s1).

yes X=[node1, node5, ..., node2]

Finally, we can express goals of the logical engine such

as:

:- path(node1, node2, X, s2).

no

or

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R23

Conclusions and ongoing work

The A

N

Managem

ent fram

ework

exploits netw

orkprogram

mability to enable agent-based distributed strategies.

Main features are:

• extension of the traditional MIB objects into m

orepow

erful objects with user custom

izable code.

• agent programm

ability according to the Filter-Even-A

ction model

New

m

anagement

applications can

be devised

to take

advantage of the distributed and autonomous agent control.

A N

etwork Events M

ining application is under development.