UiO University of Oslo (UiO) The Faculty of Mathematics and Natural Sciences Department of Informatics Course INF9050 -

UiO

University of Oslo (UiO)The Faculty of Mathematics and Natural SciencesDepartment of InformaticsCourse INF9050 - http://www.uio.no/studier/emner/matnat/ifi/INF9050/ 1

Internet traffic engineering using multi-protocol label

switching (MPLS)

Copyright © 2015

Konstantinos Lizos

Email: Email: [email protected]

Strive for progression,

not perfectionSeen at Domus Athletica

UiO

Contents

University of Oslo (UiO)The Faculty of Mathematics and Natural SciencesDepartment of Informatics Copyright © Lizos 2015 2

Functionality of MPLS and examples

Introduction in MPLS

MPLSdelineation

History and requirements of

modern networks

Comparison pro and after MPLS

Conclusions

Future DirectionsMPLS PlanesTE processing

model and Taxonomy

MPLS benefits and problems

UiO

MPLS is a layer 2.5 protocol


•Physical

•IP

•Applications

•TCP •UDP

•PPP •FR •ATM

•MPLS1

•Ethernet

•MPS2

•DWDW3

1 – Multiprotocol Label Switching (MPLS)

2 - Multi Protocol Lamda Switching (MPλS)

3 – Dense Wavelength-division multiplexing (DWDW)

Copyright ® Lizos

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MPLS History (1/2)


MPLS stands for Multiprotocol Layer SwitchingMPLS stands for Multiprotocol Layer Switching

Impetus for the realization of MPLS originated from the Impetus for the realization of MPLS originated from the requirement to tackle with growth and performance from major requirement to tackle with growth and performance from major internet service providersinternet service providers

Initially, it was perceived as a method to accelarate packet Initially, it was perceived as a method to accelarate packet delivery in legacy routers with software-based forwardingdelivery in legacy routers with software-based forwardingMPLS Applications: MPLS Applications:

I) traffic engineering (encompassing measurement, modeling, I) traffic engineering (encompassing measurement, modeling, characteri-zation and control of Internet Traffic, mainly transport characteri-zation and control of Internet Traffic, mainly transport of IP traffic through a given network in the most efficient, of IP traffic through a given network in the most efficient, economical reliable and expeditious manner possible) economical reliable and expeditious manner possible)

II) QoS management in IP networksII) QoS management in IP networks

III) Virtual Private Networks (VPNs)III) Virtual Private Networks (VPNs)

IV) Control Plane has been generalized and standardized as GMPLS IV) Control Plane has been generalized and standardized as GMPLS

UiO

MPLS History (2/2)


1994: Toshiba presents Cell Switch Router (CSR) ideas to IETF BOF

1996: Ipsilon, Cisco and IBM announce label switching plans 1997: IETF MPLS Working Group formed 1999: First MPLS VPN (L3VPN) and TE deployments 2000: MPLS Traffic Engineering 2001: First MPLS RFCs released 2002: AToM (L2VPN) 2004: GMPLS; Large Scale L3VPN 2006: Large Scale TE 2007: Large Scale L2VPN 2009: Label Switching Multicast 2011: MPLS Transport Profile

UiO Requirements of modern networks


Internet expands whether we like it or notCurrent protocols fail to cope with such expansionRequirement: Scalability

Presence of resources, optimal topology architectureCurrent status: Sparse and inefficient use of available

resources, failure to ensure QoS, variable and unnecessary network elements

Trifold requirement: A) minimize deployment costs, B) guarantee QoS throughout user experience, C) effectively administrate resources to prevent underutilization

Traffic engineering – plays a crucial/central role in performance optimization of IP networks and averting long-term degradation. Current limitations are levied on existing protocols. Requirement: Facilitation of traffic engineering

UiO

Comparison of MPLS era timeline


Anterior - MPLS

•Best Effort Service Scalability limitations Poor end-user experience Potential service

deterioration Absence of network

robustness Non-optimized costs

•Internet Traffic Engineering limitations

Traffic control Resource control & Measurement

•IP routers can’t estimate network traffic matrix from interface statistics on the routers•Difficult to determine which source-destination pairs contribute to the congestion and the proportion of traffic contributed by each pair

Posterior - MPLS

•Multi-service infrastructure

Scalability capability

Enhancing QoS

Improving long-view performance

Fault recovery & restoration

Deployment cost minimization

•Separation of control & data plane in network switching elements

•Resource availability and traffic characteristics are taken into consideration in making routing decisions, overcoming congestion in some network segments and avoiding preponderance of under-utilized links

• Mixed control & data plane in network switching elements

UiO MPLS: Connection Oriented Packet Switching


Application

Transport

Internet

Data Link

MPLS

Data Link

MPLS

Data Link

•Ethernet •Ethernet•Core Network

MPLS

Application

Transport

Internet

Data Link

MPLS

Implemented as an individual layer between IP layer and Data Link Implemented as an individual layer between IP layer and Data Link LayerLayer

Merges the notion of Packet Switched networks and Connection-Merges the notion of Packet Switched networks and Connection-oriented approachoriented approach

UiO

Realization of MPLSRealization of MPLS


- Short fixed-length label to packets at the ingress to an MPLS Short fixed-length label to packets at the ingress to an MPLS domaindomain

- Labels are assigned, based on the concept of Forwarding Labels are assigned, based on the concept of Forwarding Equivalence Class (FEC) utilized for forwarding purposesEquivalence Class (FEC) utilized for forwarding purposes

- Labels with the same FEC are assigned the same label at an Labels with the same FEC are assigned the same label at an ingress node to an MPLS domain and should ingress node to an MPLS domain and should typicallytypically traverse traverse through identical venues across the MPLS networkthrough identical venues across the MPLS network

- FEC can consist of packets FEC can consist of packets

Belonging to the same traffic flowBelonging to the same traffic flow

Belonging to the same service class, requiring similar Belonging to the same service class, requiring similar QoS/packet treatment, through the same ingress/egress QoS/packet treatment, through the same ingress/egress nodesnodes

Entering and exiting to the same ingress/egress node, Entering and exiting to the same ingress/egress node, respectivelyrespectively

In essence, MPLS enables the allocation and binding of labels to In essence, MPLS enables the allocation and binding of labels to various granularities of flows in a packet-switched networkvarious granularities of flows in a packet-switched network

UiO

MPLS venues

- Label Switched Path (LSPs) is the route, through which a Label Switched Path (LSPs) is the route, through which a designated FEC is required to follow.designated FEC is required to follow.

- Explicit LSP path is determined at its originated nodeExplicit LSP path is determined at its originated node

- A unique attribute of MPLS is label stacking.A unique attribute of MPLS is label stacking.

- Label stacking: permit multiple labels to be assigned to the Label stacking: permit multiple labels to be assigned to the same packets at one or more nodes in the network, in a same packets at one or more nodes in the network, in a hierarchical arrangment.hierarchical arrangment.

- Label Switching routers (LSRs) are those routers which can Label Switching routers (LSRs) are those routers which can forward both MPLS labeled and conventional IP packets, forward both MPLS labeled and conventional IP packets, respectively.respectively.

- Label edge routers (LERs) are the LSRs at the edge of an Label edge routers (LERs) are the LSRs at the edge of an MPLS network, responsible for assigning labels to packets. MPLS network, responsible for assigning labels to packets.

- Signaling protocol may also convey various types of attributes Signaling protocol may also convey various types of attributes associated with explicit LSPs.associated with explicit LSPs.

University of Oslo (UiO)The Faculty of Mathematics and Natural SciencesDepartment of Informatics Copyright © Lizos 2015

UiO

Label Switched Routers (LSRs)


Data plane

IPIP Forwarding TableIP inIP out

IP

Label Swapping Table

MPLS inMPLS out

57 data

16 data

represents IP Lookup + label push

represents label pop + IP lookup

Copyright ® Lizos

UiO Interior and boundary nodes in an MPLS network


47.1

47.247.4

IP 47.1.1.1

Dest Out

47.0 0 47.1 1

47.2 2

1

23

Dest Out

47.1 147.2 2

47.3 3

1

2

1

2

3

IP 47.1.1.

1

IP 47.1.1.1 IP

47.1.1.1

Dest Out

47.0 0

47.1 1 47.2 2

Boundary nodesBoundary nodes

Interior nodesInterior nodes

0

•47.3

0

UiO MPLS Forward – Cisco Routing Example


128.89

1

01

0

Routing Updates (OSPF, EIGRP, …)

You Can Reach 128.89 and 171.69 Thru Me

You Can Reach 171.69 Thru Me




In Label

Address

Prefix128.89

171.69

1

1

OutI’face

OutLabel

In Label

Address

Prefix128.89

171.69

0

1

OutI’face

OutLabel

In Label

Address

Prefix128.89 0

OutI’face

OutLabel

… … … … … …

171.69

Copyright ® [4]

UiO

MPLS Control plane


- MPLS plane – a) forwarding plane and b) control planeMPLS plane – a) forwarding plane and b) control plane

- Control plane: array of protocols, collectively establishing network Control plane: array of protocols, collectively establishing network level functionality in MPLSlevel functionality in MPLS

- Protocols are implemented as software processes that Protocols are implemented as software processes that communicate with each other, across node boundaries using communicate with each other, across node boundaries using message passing. message passing.

- Message formats, syntax, semantics and transaction sequence Message formats, syntax, semantics and transaction sequence for the message exchange are designated by the protocol for the message exchange are designated by the protocol specificationsspecifications

- Control plane aids the establishment of label switched paths in Control plane aids the establishment of label switched paths in MPLS networksMPLS networks

- Control plane is responsible to audit network topology and Control plane is responsible to audit network topology and resource availability, utilizing a routing protocol and sustain resource availability, utilizing a routing protocol and sustain signaling requirements such as create or demolish LSPs.signaling requirements such as create or demolish LSPs.

- Establishment of LSPs may be subject to various preferences Establishment of LSPs may be subject to various preferences and constraints.and constraints.

UiO Conceptual view of MPLS control plane and forwarding plane


Forw

ardi

ng

Forw

ardi

ng

plan

epl

ane

Con

trol

Con

trol

plan

epl

ane

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MPLS Traffic Engineering


Control planeControl plane

The main two subsystems for MPLS Traffic Engineering control plane The main two subsystems for MPLS Traffic Engineering control plane areare

Signaling protocol with all pertinent extensionsSignaling protocol with all pertinent extensions

Routing protocol with applicable extensionsRouting protocol with applicable extensions

Forwarding planeForwarding plane

Data path within a network element through which user traffic traffic Data path within a network element through which user traffic traffic traverses. traverses.

Performs label swapping operations using lookup tables and Performs label swapping operations using lookup tables and miscellaneous packet treatment functions such as scheduling, queue miscellaneous packet treatment functions such as scheduling, queue management, rate shaping, policing and others. management, rate shaping, policing and others.

MPLS control is typically implemented as a software module whereas MPLS control is typically implemented as a software module whereas MPLS forwarding is generally constructed on hardware to support high MPLS forwarding is generally constructed on hardware to support high speed operations (scalability)speed operations (scalability)

UiO Functional view of control and forwarding plane


Routing

Data Plane

Protocol stack

Signaling

Control Plane

Path Selection

Local resource control

Label swapping

Packet forwarding

Packet treatment

Routing

Data Plane

Protocol stack

Signaling

Control Plane

Path Selection

Label swapping

Packet forwarding

Packet treatment

•Protocol Transactions

•Bearer Channels

Local resource control

UiO

Traffic Engineering process model


Process model of TEProcess model of TE

represents the different phases in represents the different phases in the lifecycle of traffic engineering the lifecycle of traffic engineering in an operational context.in an operational context.

It is both iterative and cyclicIt is both iterative and cyclic

Categorized into four main phasesCategorized into four main phases• Policy formulation phasePolicy formulation phase• Data acquisition phaseData acquisition phase• Analysis and Analysis and

characterization phasecharacterization phase• Performance optimization Performance optimization

phasephaseInteraction between the phases is Interaction between the phases is characterized by major and minor characterized by major and minor workflow cyclesworkflow cycles

•

Policy Formulation Phase

•Analysis & Characterization Phase

•

Data Acquisition Phase

•Performance Optimization Phase

Phases InteractionPhases Interaction

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ycle

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Taxonomy of TE Systems


Taxonomy provides a classification system for different types of traffic Taxonomy provides a classification system for different types of traffic engineering methodologies. It derives from «traffic engineering engineering methodologies. It derives from «traffic engineering styles» which are abstractions of important traffic engineering styles» which are abstractions of important traffic engineering methodologies. methodologies.

Predictive

Vs.

Descriptive

Online

Vs.

Offline

Dynamic

Vs.

Static

Open Loop

Vs.

Closed Loop

Time Dependent

Vs.

State Dependent

Proactive

Vs.

Reactive

Centralized

Vs.

Distributed

Local Info

Vs.

Global Info

Tactical

Vs.

Strategic

UiO

IP over ATM / Frame Relay


ATM

Network

ATM Switches

IP routers

1)Channel Service Unit/Data Service Unit

2)Data Circuit-terminating Equipment

Frame Relay

2) DCE or Frame

Relay Switch1)CSU/DSU

Traffic management Traffic management & constraint-based & constraint-based routing of the 2nd routing of the 2nd technology can be technology can be exploited to exploited to implement TE implement TE objectivesobjectives

DisadvantagesDisadvantages

A) Added cost of A) Added cost of building and building and managing two managing two indepedent networks indepedent networks with different with different operations and operations and technologiestechnologies

B) Scalability for the B) Scalability for the number of number of adjacencies between adjacencies between routers O(routers O(NN22))

UiO

MPLS benefits and problems


Advantages MPLS offers relative to overlay Advantages MPLS offers relative to overlay modelmodel

1)1)Fewer network elementsFewer network elements

2)2)Lower operating costsLower operating costs

3)3)Greater reliability since fewer network Greater reliability since fewer network elements exist along the routed pathelements exist along the routed path

4)4)Potentiallly less latencyPotentiallly less latency

5)5)Simplified network architecturesSimplified network architectures

ProblemsProblems

1)1)Mapping ingress Mapping ingress traffic into FECstraffic into FECs

2)2)Mapping FECs onto Mapping FECs onto LSPs.LSPs.

3)3)Mapping LSPs onto Mapping LSPs onto the physical network the physical network topologytopology

Utilizing MPLS for TE provides equivalent or even superior Utilizing MPLS for TE provides equivalent or even superior capabilities to the overlay model in an integrated fashion on a single capabilities to the overlay model in an integrated fashion on a single network element.network element.

IETF RFC-2702 enables to serve as an effective means to implement IETF RFC-2702 enables to serve as an effective means to implement various traffic engineering policies in IP networks. various traffic engineering policies in IP networks.

Expansion of MPLS to support Diffserv-aware traffic Expansion of MPLS to support Diffserv-aware traffic

Control plane capability expansion for MPControl plane capability expansion for MPλλS and GMPLS.S and GMPLS.

UiO Protocol extensions to support MPLS TE


Requirement: allow constraint-based routing to be implemented Requirement: allow constraint-based routing to be implemented cost-effectively in IP networks. Map connection characteristics and cost-effectively in IP networks. Map connection characteristics and performance requirements with various attributes that can be performance requirements with various attributes that can be associated with network resources to specify various resource associated with network resources to specify various resource attributes and constraints and to modulate the routing of traffic attributes and constraints and to modulate the routing of traffic trunks over them. trunks over them.

Extensions of MPLS support the assignment of various types of Extensions of MPLS support the assignment of various types of attributes to LSP-tunnels such as bandwidth characteristics, resource attributes to LSP-tunnels such as bandwidth characteristics, resource affinities, resilience attributes, priority attributes, preemptive affinities, resilience attributes, priority attributes, preemptive capabilities and many others. capabilities and many others.

resource affinities: indicate general classes of resources to include resource affinities: indicate general classes of resources to include or exclude from the path of an LSP-tunnel.or exclude from the path of an LSP-tunnel.

Resilience attributes indicate survivability requirements of an LSP-Resilience attributes indicate survivability requirements of an LSP-tunneltunnel

Priority attribute impose a partial order between different LSP-Priority attribute impose a partial order between different LSP-tunnelstunnels

Preemptive capabilities stipulate the conditions under which one Preemptive capabilities stipulate the conditions under which one LSP-tunnel can preempt another when they contend for the same LSP-tunnel can preempt another when they contend for the same resources.resources.

UiO

Future Directions


Highlighting aspects related to policy-based MPLS network management, customer Highlighting aspects related to policy-based MPLS network management, customer network management (CNM) and advanced service level agreement (SLA) network management (CNM) and advanced service level agreement (SLA) management.management.

Constraint-based routing will be in the future a focal activity concerning MPLS TE.Constraint-based routing will be in the future a focal activity concerning MPLS TE.

IP over optical architectures and inter-connection models will be an active research IP over optical architectures and inter-connection models will be an active research area along with the inter-domain traffic engineering that remains an important area along with the inter-domain traffic engineering that remains an important research problem.research problem.I. Policy-based MPLS network managementI. Policy-based MPLS network management

Ultimate goal is to provide the capability to manage heterogeneous networks in a Ultimate goal is to provide the capability to manage heterogeneous networks in a uniform fashion, preferably from business directives without fixation on the uniform fashion, preferably from business directives without fixation on the underlying technologies. underlying technologies.

We distinguish between two levels of policy-based network management:We distinguish between two levels of policy-based network management:

(1)(1)High order policy-based managementHigh order policy-based management

It is concerned with creating an abstraction layer between business logic and It is concerned with creating an abstraction layer between business logic and network logic.network logic.

(2)(2)Lower order policy-based managementLower order policy-based management

It is implemented within the network itself and involves resolving low level policy It is implemented within the network itself and involves resolving low level policy issues within the networkissues within the network

UiO Interplay for MPLS policy-based management


Policy

Repository

Policy Management

Interface

Policy Decision

Point

A high order policy-based management A high order policy-based management infrastructure contains the followinginfrastructure contains the following

1)1)Policy management interfacePolicy management interface

2)2)Policy decision pointPolicy decision point

3)3)Policy repository Policy repository

4)4)Policy enforcement pointsPolicy enforcement points

The policy repository is an interface to The policy repository is an interface to the policy management system.the policy management system.

It stores persistent policy informationIt stores persistent policy information

Policy decision point converts high Policy decision point converts high order policy logic into network order policy logic into network management and control logic.management and control logic.

Policy enforcement points are Policy enforcement points are responsible for executing the final responsible for executing the final decisions by implementing or activating decisions by implementing or activating network control functions.network control functions.

TE control plane can be interpreted as TE control plane can be interpreted as policy decision point and policy policy decision point and policy enforcement pointenforcement point

UiO

Future directions


II. Customer network management (CNM)II. Customer network management (CNM)

CNM allows a customer to modify and monitor the services as CNM allows a customer to modify and monitor the services as received from the network by interacting with a CNM portal received from the network by interacting with a CNM portal situated within the service provider networksituated within the service provider network

Business drivers for CNM center around operational cost reduction Business drivers for CNM center around operational cost reduction and enhancing the economies of scale of the network, so that the and enhancing the economies of scale of the network, so that the cost of customer service will not increase proportionally with the cost of customer service will not increase proportionally with the number of customer subscribed to the network (cost of operating number of customer subscribed to the network (cost of operating the network will not grow proportionally with the size of the the network will not grow proportionally with the size of the network and the subscribed customer base)network and the subscribed customer base)

Firmly close is the concept of CNM – the end-to-end flow through Firmly close is the concept of CNM – the end-to-end flow through provisioning which enables provisioning of network services in a provisioning which enables provisioning of network services in a completely automated fashion, without human intervention at completely automated fashion, without human intervention at intermediate points of the network. Also, it is adjacent to the idea intermediate points of the network. Also, it is adjacent to the idea of advanced SLA management which can exploit the MPLS TE of advanced SLA management which can exploit the MPLS TE capabilities in large-scale IP networks.capabilities in large-scale IP networks.

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Future Directions


III. IP over optical inter-connection architectures and modelsIII. IP over optical inter-connection architectures and models

Following into are the overlay model, peer model and augmented Following into are the overlay model, peer model and augmented modelmodel

Peer model: security, scalability, fault containment, performance Peer model: security, scalability, fault containment, performance optimization, routing control, signaling control, link management, optimization, routing control, signaling control, link management, resource allocation e.t.c.resource allocation e.t.c.

IV. Inter-domain traffic engineeringIV. Inter-domain traffic engineering

An intra-domain TE involves TE within a given autonomous system An intra-domain TE involves TE within a given autonomous system in the Internet. in the Internet.

The issue of inter-domain TE - thus traffic engineering across The issue of inter-domain TE - thus traffic engineering across autonomous and possible heterogeneous networks and systems - autonomous and possible heterogeneous networks and systems - presents also challenging research interest for future studies.presents also challenging research interest for future studies.

V. GMPLS: Perhaps the most significant advancement in the V. GMPLS: Perhaps the most significant advancement in the evolution of MPLS is the extension and generalization of the MPLS evolution of MPLS is the extension and generalization of the MPLS TE control plane. TE control plane.

UiO

Conclusions


Summarizing the basic concepts of MPLS and its applications to Summarizing the basic concepts of MPLS and its applications to Internet TEInternet TE

•Separation of forwarding information (label) from the content of Separation of forwarding information (label) from the content of the IP headerthe IP header

•Use of different technologies and link layer mechanisms to Use of different technologies and link layer mechanisms to realize the label swapping forwarding paradigmrealize the label swapping forwarding paradigm

•Flexibility in the formation of FECFlexibility in the formation of FEC

•Process model for TE is discussed along with TE considerations in Process model for TE is discussed along with TE considerations in combined MPLS and Diffserv networkscombined MPLS and Diffserv networks

•Ongoing efforts include for example the emergence of intelligent Ongoing efforts include for example the emergence of intelligent optical inter-networking systems in the future, with sophisticated optical inter-networking systems in the future, with sophisticated bandwidth provisioning capabilities and dynamic wavelength bandwidth provisioning capabilities and dynamic wavelength routing in IP networks.routing in IP networks.

•Fundamental research and development issues remain Fundamental research and development issues remain unexplored in constraint-based routing, policy-based management unexplored in constraint-based routing, policy-based management of MPLS networks, Customer network management and IP over of MPLS networks, Customer network management and IP over optical architectures and inter-connection models utilizing GMPLS.optical architectures and inter-connection models utilizing GMPLS.

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Mobile IP/NAT Intelligence Presentation - Copyright © ANPT 2004 28

Q & A

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Course INF9050 - http://www.uio.no/studier/emner/matnat/ifi/INF9050/University of Oslo (UiO)The Faculty of Mathematics and Natural SciencesDepartment of Informatics 1

Internet traffic engineering using multi-protocol label switching (MPLS)

Copyright © 2015

Konstantinos Lizos

Email: [email protected]

UiO References


1) Daniel O. Awduche, Bijan Jabbari, "Internet traffic engineering using multi-protocol label switching (MPLS)", Computer Networks 40 (2002) 111-1292) F. Fahim, Constraints based routing algorithms andapplications, in: Proceedings of MPLS’98, McLean, Virginia,October 1998.3) K. Kar, M. Kodialam, T.V. Lakshman, Minimum interf. routing of bandwidth guaranteed tunnels with MPLS traffic engineering applications, IEEE Jour. on Sel. Areas in Com. 18 (12) (2000).4) Cisco.com

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UiO University of Oslo (UiO) The Faculty of Mathematics and Natural Sciences Department of Informatics Course INF9050 -