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DIANA: Scenarios for QoS based  integration of IP and ATM  EU IP/ATM cluster meeting, Lausanne        Switzerland Feb 11, ...
MotivationATM and IP evolution have some commonalties:   need for QoS ,   need for more capacity in the network,   need fo...
Objectives of the projectTo develop, integrate, validate and demonstrate resource reservationand traffic control functiona...
Project PartnersAssociation Swisscom & Ascom               SwitzerlandUniversity of Stuttgart                    GermanyTe...
QoS strategies for IPResource Reservation Protocol (RSVP)    per flow reservation    role: in access networks, for real ti...
Resource Reservation Protocol (RSVP) designed for an Integrated Service Internet (Guaranteed & Controlled Load), provides ...
RSVP over ATM Framework                  PRO                  Aggregation of traffic                  streams at the ingre...
RSVP over ATM Implementation                CLIP address resolution: Proof of                concept                UNI si...
Interworking ScenariosOverlay model (Scenario 1)             Peer model (Scenario 2)          Integration unit            ...
RSVP over ATMOverlay model where common layer is IP and ATM as a link layer,control plane mappings required, IETF RFCs
RSVP peering with ATMIntegration Unitterminates both RSVPand ATM signaling.Two approaches forsetting up the ATMsection for...
RSVP & DiffServ Interworking Over ATM Int-serv                                          Diff-serv                     Int-...
Dynamic Bandwidth Management
RSVP over ATM IssuesManagement of QoS data, VCs and VC for controlmessaging (RSVP-messaging)ITU SG11 looking into possibil...
Scalable Reservation Protocol (SRP)  Inband signaling for "Controlled Load" services  routers aggregate the flows on outpu...
SRP Reservation MechanismDESIGN GOALSScalability: No SRProuter manages per-flowstateAbsolute reservationSoft state: Flow o...
SRP Implementation Framework                      PRO                           Realizes absolute                         ...
SRP over ATMBW                                   = ATM reservation                                   based on estimates   ...
SRP Performance Example                                                            Observed performance                0,6...
SRP over ATM IssuesDue to the inband nature of the SRP, overlay model is themost naturalSRP builds up reservations gradual...
Simple Integrated Media AccessWHY DIFFERENTIATED SERVICES?            HOW DOES SIMA IMPLEMENT                             ...
SIMA / DiffServ                                                                 CE = Customer Equipment                   ...
SIMA Drop Preference Levels Actual Bit     Drop              Preference   If the network is dimensioned properly:   Rate  ...
Packet scheduling and Buffering        DPa = f(Mrt, Mnrt)                        Mrt                                rt    ...
SIMA Implementation FrameworkSIMA in the DIANA IUAccess node functionality    Measure & classify data into    flows    Che...
SIMA Performance Example                                                                    Example exhibits weight (NBR) ...
SIMA Over ATM IssuesSIMA is developed for IP, could be reworked for ATM (intheory)Uses ATM as a link between SIMA routersU...
Comparison of IP QoS strategies & ATM QoS              RSVP                                    SRP                        ...
SummaryRSVP over ATM                    SRP                       SIMA •Layered architecture     •IP architecture         ...
Trial ScenarioDISTRIBUTED INFRASTRUCTURE More realistic traffic scenario RSVP over ATM Signaling (re-negotiation) becomes ...
Planned Performance Experiments  RSVP over ATM                       Application controlled      How does aggregation affe...
Design of the Integration Unit   HW based on Flextel´s Multi Purpose Switch/Router   open SW environment (Linux)   started...
Design of the Integration UnitHW based on Flextel´s Multi Purpose Switch/Routeropen SW environment (Linux)started with RSV...
ConclusionDIANA platform has the ability to verify a number of approachesthe project aims to provide answers to evolution ...
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DIANA: Scenarios for QoS based integration of IP and ATM

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Presentation of research project at the EU IP/ATM cluster meeting in February 1999.

EU IP/ATM cluster meeting, Lausanne Switzerland February 11, 1999

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DIANA: Scenarios for QoS based integration of IP and ATM

  1. 1. DIANA: Scenarios for QoS based integration of IP and ATM EU IP/ATM cluster meeting, Lausanne Switzerland Feb 11, 1999 John Loughney Nokia Research Center
  2. 2. MotivationATM and IP evolution have some commonalties: need for QoS , need for more capacity in the network, need for efficient resource usage (multicasting, multiplexing, dynamism etc..),ATM is an established transport layer technology, but IP dominates inapplication side & is a hot technologyin order to evaluate the options we should look into areas where ATMand IP overlap, conflict and complete each other: QoS basedinterworking between ATM and IP
  3. 3. Objectives of the projectTo develop, integrate, validate and demonstrate resource reservationand traffic control functionalities which seamlessly interoperatebetween ATM and IP networks to achieve QoS.At the boundary between the ATM and IP domains, DIANA willtranslate between IP QoS and ATM QoS mechanisms. Alternative IPQoS schemes are addressed (RSVP, SPR, SIMA/diff. serv.) and theirrelationship to ATM QoS is studied.The experimental prototyping in DIANA will allow the investigation,testing and validation of different approaches for the convergence ofIP and ATM
  4. 4. Project PartnersAssociation Swisscom & Ascom SwitzerlandUniversity of Stuttgart GermanyTelenor Research & Development NorwayFinsiel ItalyFlextel ItalyNokia FinlandAscom Hasler AG SwitzerlandEcole Polytechnique Federale de Lausanne SwitzerlandSwisscom SwitzerlandTelscom AG Switzerland
  5. 5. QoS strategies for IPResource Reservation Protocol (RSVP) per flow reservation role: in access networks, for real time applicationsScalable Reservation Protocol (SRP) adaptive, aggregated reservations role: core and access, for adaptive applicationsDifferentiated Services/SIMA aggregating, priority based perfect match for core networks
  6. 6. Resource Reservation Protocol (RSVP) designed for an Integrated Service Internet (Guaranteed & Controlled Load), provides end-to-end QoS reservations for uni-directional flows, operates on top of IP4 and IP6, out band "signaling" supports multicasting, receiver oriented, relies on periodical refreshments (soft state) scalability problems with large numbers of flows R1 Path S1 Resv R2 Multicast Packet Flow Path message (multicast) Resv message (unicast)
  7. 7. RSVP over ATM Framework PRO Aggregation of traffic streams at the ingress to ATM: + Scalability Traffic descriptor & QoS parameter based resource reservation end-to-end: Exact & reliable guarantee CON Layered routing, addressing & traffic control Different signaling protocols
  8. 8. RSVP over ATM Implementation CLIP address resolution: Proof of concept UNI signaling with dynamic re- negotiation However, focus is on traffic control Flow-to-VC aggregation Dynamic, threshold based VC bandwidth renegotiation (cf. ACTS REFORM)
  9. 9. Interworking ScenariosOverlay model (Scenario 1) Peer model (Scenario 2) Integration unit Integration unit Common transport layer Transport Layer A Transport Layer B Technology X Technology Y Technology X Technology Y • translation of user plane, find • what is the common layer? common "application" layer: RTP RTP, UDP (TCP), IP? ... Results into application specific • Majority of applications use IP interworking • Mapping of addressing, QoS •translation of control plane parameters, control plane • translation of addressing, QoS interworking parameters, ...
  10. 10. RSVP over ATMOverlay model where common layer is IP and ATM as a link layer,control plane mappings required, IETF RFCs
  11. 11. RSVP peering with ATMIntegration Unitterminates both RSVPand ATM signaling.Two approaches forsetting up the ATMsection for originatingATM host:1) it is set up only afterRSVP section is done2) sequentiallyIn some case loss ofdata may occur, QoSnegotiationproblematic,application levelinterworking on userplane.
  12. 12. RSVP & DiffServ Interworking Over ATM Int-serv Diff-serv Int-serv Sending Receiving Stub network ER1 Transit network ER2 Stub network host host Data stream: best effort RSVP Path RSVP Resv RSVP Resv DACS RSVP Resv Data stream: QoS Diff. Serv over ATM Note: diff-serv bits can be set at ER1: Data stream Data stream with diff-serv bits Data stream with diff-serv bits
  13. 13. Dynamic Bandwidth Management
  14. 14. RSVP over ATM IssuesManagement of QoS data, VCs and VC for controlmessaging (RSVP-messaging)ITU SG11 looking into possibility to embed RSVPmessaging into Generic Identifier IE in ATM signalingchange of QoS: ATM allows change of PCR and SCR, notservice category, establishment of new VCrelease of VCset up of a VC is a costly operation; implies flow to VCaggregation among RSVP sessionsmulticast support
  15. 15. Scalable Reservation Protocol (SRP) Inband signaling for "Controlled Load" services routers aggregate the flows on output ports sources request resources; routers estimate reserved bandwidth to decide on admission and propagate requests; receivers send feedback to source sources adjust traffic based on the feedback from receivers failed reservation requests are degraded (to best effort) Sender Data & reservations Receiver Feedback Router
  16. 16. SRP Reservation MechanismDESIGN GOALSScalability: No SRProuter manages per-flowstateAbsolute reservationSoft state: Flow of datapackets marked asreserved or requestmaintain or upgrade thereservationNo traffic descriptor andQoS parameter based(explicit) signalingIP layer solution
  17. 17. SRP Implementation Framework PRO Realizes absolute reservation with a scaleable architecture Can be embedded in IP DiffServ architecture Relatively simple traffic control in routers CON No explicit QoS parameters Builds upon the LINUX DiffServ architecture Feedback control that DIANA (EPFL) has Sensitive to route co-developed changes Policing more complex
  18. 18. SRP over ATMBW = ATM reservation based on estimates Time ATM signaling latency
  19. 19. SRP Performance Example Observed performance 0,6 SRP builds up reservation 2 SRP sources gradually (starting from BE) 0,5 (long ON and OFF periods) Transient phases 0,4 SRP provides stableReserved Rate 0,3 reservation Further work 0,2 Completion of the LINUX 0,1 framework: IP over ATM, DiffServ & SRP queuing 0,0 0e+0 5e+4 1e+5 2e+5 2e+5 discipline Time Policing
  20. 20. SRP over ATM IssuesDue to the inband nature of the SRP, overlay model is themost naturalSRP builds up reservations gradually, while ATM expectsthe connection parameters to be known at connection setup. A request packet that is destined to an ATM VC withoutenough capacity can cause: a new connection set up re-negotiation of an existing connectionThese are costly operations, anticipation of futureconnections needed
  21. 21. Simple Integrated Media AccessWHY DIFFERENTIATED SERVICES? HOW DOES SIMA IMPLEMENT DIFFERENTIATED SERVICES?Integrated Services provide absolute Customer profile expressed in& reliable QoS terms of a nominal bit rateBUT per-flow state has to be Real-time or non real-timeestablished and managed: Not service selection for a flowscaleable Drop priority of a flowDS achieve scalability by classifying dynamically depends onand marking packets at the ingress current bit rate to NBR ratioto a DS network 8 drop preference and 2 delayProfile based access priority (rt/nrt) levelsDS can provide relative QoS using Defines access & core routersimple, scaleable mechanisms functionality
  22. 22. SIMA / DiffServ CE = Customer Equipment A = Access Node C C C = Core Node CE A SIMA network A CE C C• Access node (A): • knows NBR and measures actual bit rate of flow (MBR) • determines and sets the drop preference of each packet (from 0 to 6)• Core network node (C): • discards packets based only on the drop preference of the packet and buffer occupancy levels • places the accepted packet either in the real-time or nrt buffer • does not need to know anything about the NBR or the traffic process of separate connections • no capacity reservation (CAC or RSVP)
  23. 23. SIMA Drop Preference Levels Actual Bit Drop Preference If the network is dimensioned properly: Rate Reserved for non-SIMA services DP =7 with resource reservation NBR/4 DP=6 Excellent quality High quality, packet losses only during NBR/2 DP =5 exceptional traffic peaks Good quality: Small packet loss even NBR DP =4 during busy hours Moderate quality: usually small packet 2 NBR DP =3 loss ratio except for busy hours Satisfactory quality: from time to 4 NBR DP =2 time very high packet loss ratio Suitable for best effort during 8 NBR DP =1 busy hours Unusable during busy hours: 16 NBR DP =0 suitable for BE during idle hours
  24. 24. Packet scheduling and Buffering DPa = f(Mrt, Mnrt) Mrt rt + yes DP ≥ DPa rt/nrt Mnrt no (discard) nrtDP = preference of the incoming packet Mrt = occupancy level of real-time bufferDPa = allowed drop preference level Mnrt = occupancy level of nrt buffer
  25. 25. SIMA Implementation FrameworkSIMA in the DIANA IUAccess node functionality Measure & classify data into flows Check against NBR Calculate priorityCore node functionality Drop & delay priority based on DS bits and buffer occupancyOptions Dynamic NBR (RSVP & DiffServ) Exploiting ATM´s flexibility as L2
  26. 26. SIMA Performance Example Example exhibits weight (NBR) 0.6 proportional fairness 0.5 1 Node, 5 TCP like sources Further research required toNormalised Throughput 0.4 investigate the impact of dynamic 0.3 priority assignment during 0.2 congestion epochs the interaction with TCP´s 0.1 flow and congestion 0.0 control 0.0 0.1 0.2 0.3 the behavior in large scale Nominal Bit Rate networks
  27. 27. SIMA Over ATM IssuesSIMA is developed for IP, could be reworked for ATM (intheory)Uses ATM as a link between SIMA routersUsual IP over ATM difficulties
  28. 28. Comparison of IP QoS strategies & ATM QoS RSVP SRP DiffServ UNI4.0 Receiver requests reservation in Sender requests and maintains a Service Level Agreement, between Sender sets up a bi-directional VCresponse to a PATH message, uni- reservation by marking packets user and the ISP. directional Default best-effort service Default best-effort service Default best-effort No connectivity if set-up fails Heterogeneous QoS within a Multicast under study Multicast (still under study) Point-to-multipoint VCs with a multicast session (Homogeneous QoS planned) homogeneous QoSDynamic QoS: RESV can alter the Dynamic QoS: Request is signalled No means for signalling defined, Static QoS, negotiated at set-up reservation at any time implicitly and dynamically by static (Q.2963.x now specifies sender marking packets controlled modification procedures)Multiple reservation filter styles to n.a. Behaviour Aggregate classifier, Point-to-multipoint select different senders in a Multi Field classifiermultipoint-to-multipoint scenario Soft state: Messages are resent Soft, aggregated state in routers n.a. Hard state: Connections have to be periodically explicitly released Guaranteed, controlled load and Service similar to controlled load Many services (e.g. relative CBR, rt/nrt-VBR, ABR, (GFR), best-effort service guarantees and absolute) UBR
  29. 29. SummaryRSVP over ATM SRP SIMA •Layered architecture •IP architecture •IP DiffServ •Absolute bandwidth •Traffic & QoS reservation without per- •Nominal bit rate parameter based flow state •Relative priority•Most complex traffic •Dynamic priority control architecture •Control loop dependent on current bit rate to NBR ratio
  30. 30. Trial ScenarioDISTRIBUTED INFRASTRUCTURE More realistic traffic scenario RSVP over ATM Signaling (re-negotiation) becomes more expensive SRP Delay in control loop Policing trial SIMA Interaction with TCP flow & congestion control
  31. 31. Planned Performance Experiments RSVP over ATM Application controlled How does aggregation affect renegotiation individual QoS? Exploits RSVP´s dynamic Dynamic BW re-negotiation: re-negotiation capabilities Trade-off between reservation RVBR service for traffic efficiency and signaling load descriptor calculation SRP Reference Applications Dynamic behavior in transient VAT phases ARMIDA VoD application Policing (MPEG4): Adapts to SIMA available network Impact of dynamic marking resources Interaction with TCP Synthetic sources
  32. 32. Design of the Integration Unit HW based on Flextel´s Multi Purpose Switch/Router open SW environment (Linux) started with RSVP over ATM scenario
  33. 33. Design of the Integration UnitHW based on Flextel´s Multi Purpose Switch/Routeropen SW environment (Linux)started with RSVP over ATM scenario
  34. 34. ConclusionDIANA platform has the ability to verify a number of approachesthe project aims to provide answers to evolution considerationstest and evaluate the scenarios under considerationyear 1 started with RSVP over ATM scenario RSVP-ATM peer model seems to be problematic: no real application need, no immediate market needyear 2 starts: proof of RSVP over ATM scenario SRP over ATM promising new approach SIMA/Diff. Serv. seems more relevant than peering RSVP with ATM

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