PowerPointpresentatie

1
Generic AAA based Bandwidth on Demand
Authentication Authorization Accounting EVL at
UIC meeting Chicago 18/10/2002 Leon
Gommans Advanced Internet Research
Group University of Amsterdam lgommans_at_science.uva
.nl
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• Content
• Goals and basic list of requirements.
• Lightpath and Lightpath control concepts
• Generic AAA concepts
• High level design and operation of proof of
  concept.
• Example of a simple request message and policy.
• - Next work items

3

• Goal
• Allow a provisioned Lightpath to by-pass a
  regular internet connection. Internet connection
  becomes control channel.
• Motivation
• Routed networks are too expensive if requested
  bandwidth is in the order of the traffic
  generated by a nations NRN
• TCP stack transport channel needs tailored
  behavior to make optimal use of a high speed ( GB
  ), high delay (gt100ms) channel
• Modifications generates Internet unfriendly
  TCP traffic.
• Firewalls do (not yet) statefully inspect 10
  GB/S streams without delays or performance
  implications.
• Single Packet drop causes severe performance
  hits.
• Memory buffers in routers/switches are a concern
  when the
• road gets smaller.

4

• Rough requirements list.
• Allow lightpath usage in a demand driven
  fashion.
• Allow hard or soft pre-allocation.
• Must support allocation and usage across
  multiple domains.
• Must be integrated into middleware e.g. by
  allowing
• provisioned by-pass model to be supported by
  GridFTP.
• Raised this with GGF Data Transport RG (Bill
  Allcock).
• Allow authorized VOs or individual users to
  discover
• available lightpaths (e.g. via a OGSA/WS
  style interface).
• Allow authorized users (with a certain role
  within the VO)
• to pre-allocate and use bypass for a limited
  amount of time
• and with limits on the allocated bandwidth.
• Must integrate with existing authentication
  user (role
• based) authorization system Looking into EDG
  VOMS.

5

• Rough requirements list.
• Must hide complexity from user. Conceptually the
  user must perform the process in 3 basic steps
  after login
• Pre-allocate either manually or automatically
  thru a scheduling system -gt system issues an
  authorization.
• Allow the job to allocate the network resource
  whereby it uses the authorization.
• Once the job is finished, the authorization is
  handed back so resources can be freed.
• User (or scheduling system) must be allowed to
  change the reservation if the process flow so
  dictates.
• Allocating user may be different from ultimate
  user.
• Allocating user may subdivide capacity amongst
  users.
• Must ultimately support Grid Economic Services
  Architecture features to allow ad hoc creation.
• Must ultimately provide Grid Accounting records
  for billing in contract situations.

6

• Design considerations.
• Group in Amsterdam does focus on deploying
  Generic AAA (RFC2903/RFC2904) concepts to handle
  authorization of lightpath. Group members were
  authors.
• Best suited to handle policy based authorization
  in a dynamic fashion either to build AuthZ tokens
  or process requests which contain AuthZ tokens.
  Note AuthZ may itself also contain policies.
• Authorizations between administrative domains
  must be done at a fairly high-level.
• Dont want to address low level networking
  problems (path finding/setup) as vendors and
  researchers like ICAIR are already active in this
  area
• Need to identify role, messages and policies that
  are handled by Generic AAA components as part of
  the overall workflow.

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• Lightpath
• Def Any uni-directional point to point
  connection with effective guaranteed bandwidth
• Examples of LightPaths
• Analog wavelength on a CWDM or DWDM system
• STS channel on a SONET or SDH circuit
• ATM CBR circuit
• Diff serv gold service on a packet based
  network
• Gigabit Ethernet over dedicated fiber strand
• Definition by Bill St. Arnoud of Canarie

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Onion Lightpath model
Selector Switch
Distributor Switch
DomainY
Domain X
Domain X
Selector Switch
Distributor Switch
Domain Y
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Daisy Chain Lightpath model
Domain A
Domain B
Domain C
Domain D
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Daisy Chain Onion
Domain A
Domain B
Domain C
Domain X
Domain D
Domain X
Domain X
DomainY
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Onion control model
Seector Switch
Distributor Switch
Domain X
Domain Y
AAA
Domain AAA engine must control both selector and
distributor switch and Interconnecting network
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Daisy chain control model
Selector Switch
Distributor Switch
Domain A
Domain B
AAA
AAA
Domain AAA engine must control the selector or
distributor switch and one of the AAA
Servers must control intermediate network
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• Generic AAA
• 5 years ago a AAA server was known as a server
  supporting dail-in boxes thru the RADIUS protocol
  (at IETF).
• IETF42 (in same hotel as GGF6) held first AAA
  BOF as it was
• recognized AAA could be used in other type of
  applications.
• Amsterdam group has been participating on
  defining concepts for Generic AAA since march
  1999 when AAA WG was formed at IETF-44
• Work became IRTF subject end of 1999 (AAA ARCH
  RG).
• IDs that became RFCs 2903 2906 were
  submitted after the Adelaide IETF march 2000.
  RFCs describe framework, architecture, example
  applications and requirements.
• Optical Networking within grid environment is a
  research application for Generic AAA.

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RFC 2904 Generic AAA Framework basic principles
AAA
AAA
AAA
1
1
User
2
User
User
4
2
2
3
1
3
3
Service
Service
Service
4
4
Pull sequence NAS (remote access) RSVP (network
QoS)
Agent sequence Agents, Brokers, Proxys.
Push sequence. Tokens, Tickets, ACs etc.
3 fundamentally different user initiated
authorization sequences. Note RFC2904 does
not show step 5 service access.
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Generic AAA Framework
AAA
User Home Organization
3
4
AAA
User
Service Provider
2
5
1
Service
6
Separating the User Awareness from the
Service yield Roaming Models Example roaming
pull model.
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Generic AAA Framework
AAA
User Home Organization
AAA
AAA
User
Service
Service
AAA Client
Service Provider A
Service Provider B
Distributed Services Models allow many types and
combination of authorization sequences ..
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Generic AAA Architecture RFC2903
Policy Decision Point
Fundamental ideas inspired by work of the IETF
RAP WG that in RFC 2753 describes a framework
for Policy-based Admission Control. Foundation
for COPS
The point where policy decisions are made.
Policy Repository
Request
Decision
Policy Enforcement Point
The point where the policy decisions are actually
enforced.
Basic Goal Generic AAA Allow policy decisions to
be made by multiple PDPs belonging to different
administrative domains.
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Generic AAA Architecture RFC2903
PDP
Rule Based Engine
Archieve goal by by separating the logical
decision process from the application specific
parts within the PDP.
Policy Repository
Application Specific Module
Request
Decision
Policy Enforcement Point
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Example of Generic AAA Architecture RFC2903
Rule Based Engine
Rule Based Engine
Rule Based Engine
Policy Repository
Policy Repository
Policy Repository
Application Specific Module
Application Specific Module
Application Specific Module
Users
Contracts Budgets
AAA Server
AAA Server
AAA Server
User
Bandwidth Broker
Registration Dept.
Purchase Dept.
(Virtual) User Organization
QoS Enabled Network
Service
Bandwidth Provider
Service Organization
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Generic AAA (RFC2903) based Bandwidth on Demand
192.168.1.5
192.168.1.6
192.168.2.3
192.168.2.4
802.1Q VLAN Switch Enterasys Matrix E5
A
C
802.1Q VLAN Switch Enterasys Matrix E5
1 GB SX
B
D
Policy DB
AAA
AAA Request
iGrid2002
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Generic AAA (RFC2903) based Bandwidth on Demand
192.168.1.5
192.168.1.6
192.168.2.3
192.168.2.4
802.1Q VLAN Switch Enterasys Matrix E5
A
C
802.1Q VLAN Switch Enterasys Matrix E5
1 GB SX
B
D
Policy DB
AAA
AAA Request
iGrid2002
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Next Setup using vendor provided network
provisioning system
Managed Optical Connection Service
802.1Q VLAN Switch Enterasys SS6000
A
C
802.1Q VLAN Switch Enterasys SS6000
IP A
IP C
B
D
IP B
IP D
Cisco CTM
AAA BoDServ
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Example XML Lightpath request ltAAARequest
version"0.1" type"BoD" gt  ltAuthorizationgt     
ltcredentialgt         ltcredential_typegtsimplelt/cr
edential_typegt         ltcredential_IDgtJanJansenlt/
credential_IDgt         ltcredential_secretgtf034dlt
/credential_secretgt      lt/credentialgt 
lt/Authorizationgt  ltBodDatagt     
ltSourcegt192.168.1.5lt/Sourcegt     
ltDestinationgt192.168.1.6lt/Destinationgt     
ltBandwidthgt1000lt/Bandwidthgt     
ltStartTimegtnowlt/StartTimegt     
ltDurationgt20lt/Durationgt  lt/BodDatagtlt/AAARequestgt
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Policy (significant
part) executed by AAA Rule Based Engine if (
( ASMRM.CheckConnection(
RequestBodData.Source,
RequestBodData.Destination
) ( RequestBodData.Bandw
idth lt 1000 ) ) ) then ( ASMRM.RequestConne
ction( RequestBodData.Source,
RequestBodData.Destination,
RequestBodData.Bandwidth,
RequestBodData.StartTime,
RequestBodData.Duration )
ReplyAnswer.Message "Request
successful" ) else ( ReplyError.Message
"Request failed" )
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• Design Details
• Onion model was chosen for first implementation.
• Single AAA engine controls both ingress and
  egress switch by creating 802.1Q VLANs using the
  dot1Q Bridge MIB extentions via SNMP.
• 1 GB channel between switches carry 802.1Q
  tagged ethernet frames. An 802.1Q trunk can carry
  up to 4096 VLANs.
• End stations register with AAA engine and
  subsequently send request to reach other stations
  (pointed to via its public IP address).
• By-pass communication channel uses a private IP
  address space. Destinations are identified by
  main IP address.

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• Technical Implementation
• XML/SOAP messages for request/reply (to prepare
  for a future web services interface)
• RBE JAVA code running as Servlet.
• Uses Apache Axis to handle SOAP messages.
• ASM JAVA code currently running in Java
• context of RBE. Currently investigating how it
• could run separately e.g. as Java Bean or
  using
• CORBA.
• More technical details
• Bas van Oudenaarde oudenaar_at_science.uva.nl
  and
• Arie Taal taal_at_science.uva.nl

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• Upcomming work
• Separate ASM and RBE and allow ASMs to be
  loaded/unloaded dynamically.
• Implement pre-allocation mechanisms (based on
  GARA collaboration with Volker Sander).
• Create ASM for other B/W manager (e.g. Alcatel
  BonD, Cisco CTM, Level-3 Ontap)
• Create ASM to talk to other domain OMNInet
• Allow RBEs to talk to each other (define
  messages).
• Integrate BoD AAA client into middleware eg by
  allowing integration with GridFTP and integration
  with VOMS authentication and user authorization
  system.
• Build WS interface abstraction for pre-allocation
  and subsequent usage.

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Thank you ! Lgommans_at_science.uva.nl