Cisco Mpls -Te for Vpns

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  • 7/28/2019 Cisco Mpls -Te for Vpns

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    111 2002, Cisco Systems, Inc. All rights reserved.BW Protection

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    2 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Cisco MPLS -Traffic Engineering for VPNs

    Amrit Hanspal

    Sr. Product Manager MPLS & QoS

    Internet Technologies Division

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    333 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Agenda

    MPLS Fundamentals Application 1: Increasing Bandwidth

    Inventory

    Application 2: Minimizing Packet Loss Application 3: Optimizing the Core

    Traffic Engineering for VPNs Summary

  • 7/28/2019 Cisco Mpls -Te for Vpns

    4/41444 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    MPLS Is Key technology for Delivery ofLayer 2 & Layer 3 Services

    MPLS VPNs: BuildOnce / Sell ManyNetwork Based VPNs

    Layer 2 Integration for a SingleConverged NetworkInfrastructure

    OpticalServicesOptical

    Services

    IPServices

    IPServices

    IP+Optical SwitchIP+Optical Switch

    O-UNIO-UNI MPLSMPLS

    IPIP

    IP+Optical Integration

    ATMServices

    ATMServices

    IPServices

    IPServices

    IP+ATM SwitchIP+ATM Switch

    PNNIPNNI MPLSMPLS

    IPIP

    Traffic Engineering: Optimization for

    Additional traffic =>$$

    Traffic Engineering: Optimization for

    Additional traffic =>$$

    Protection SolutionReduction in

    CAPEX & OPEX

    Protection SolutionReduction in

    CAPEX & OPEX

    FrameRelay

    FrameRelay

    ATM

    IP+ATM Integration

  • 7/28/2019 Cisco Mpls -Te for Vpns

    5/41555 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    MPLS Layer 3 VPNs

    Scalable VPNs

    IP QoS and TrafficEngineering

    Easy to manage andNo VC provisioningrequired

    Hub/Spoke or Mesh

    Topologies can easilybe deployed

    Provides a level ofSecurity equivalent toFrame-relay and ATM

    Supports thedeploymentof new value-addedapplications

    Customer IP addressfreedom

    MPLS

    Network

    Traff ic Separation at Layer 3Each VPN Has Unique RD

    Traff ic Separation at Layer 3Each VPN Has Unique RD

    MPLS VPN RenaultMPLS VPN Renault

    MPLS VPN BankcorpMPLS VPN Bankcorp

    Corp ASite 2

    Corp ASite 3

    Corp ASite 1

    Corp BSite 2

    Corp BSite 1

    Corp BSite 3

    VPN Membership-

    Based on Logical Port

    VPN Membership-

    Based on Logical Port

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    6/41666 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Current Layer 2 VPNs With FR & ATM

    FR/ATM

    Backbone

    Blue VPN

    Red VPN

    Purple VPN

    Core has

    individual VC

    information

  • 7/28/2019 Cisco Mpls -Te for Vpns

    7/41777 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    MPLS Layer 2 VPNs Any Transport over MPLS (AToM)

    MPLSBackbone

    Blue VPN

    Red VPN

    Purple VPN

    Core does not

    have individual

    VC information

    Idea is to do the same as ATM & FRTransport layer 2 frames in MPLS packetCreate mapping of layer 2 circuits to LSPsScale better by using label stacking

  • 7/28/2019 Cisco Mpls -Te for Vpns

    8/41888 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Agenda

    MPLS Fundamentals Application 1: Increasing Bandwidth

    Inventory

    Application 2: Minimizing Packet Loss Application 3: Optimizing the Core

    Traffic Engineering for VPNs Summary

  • 7/28/2019 Cisco Mpls -Te for Vpns

    9/41999 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    IP Routing and the Fish Problem

    R8R2

    R6

    R3

    R4

    R7

    R5

    R1

    IP (Mostly) Uses Destination-Based Least-Cost Routing

    Flows from R8 and R1 Merge at R2 and Become Indistinguishable

    From R2, Traffic to R3, R4, R5 Use Upper Route

    Al ternate Path Under-Utilized

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    10/41101010 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Router F

    The Problem with Shortest-Path

    Changing to A->C->D->E

    wont help

    Router C Router D

    Router G

    80MbT

    raffic

    80MbT

    raffic

    35MbDrops!

    35MbDrops!

    Router A

    Router B

    NodeNode Next-HopNext-Hop CostCost

    BB 1010BB

    FF 3030BB

    CC 1010CCDD 2020CC

    EE 2020BB

    GG 3030BB

    OC-3

    OC-3

    DS3

    DS3

    DS3OC-3

    OC-3

    Some links are DS3, someare OC-3

    Router A has 40Mb of traffic forRoute F, 40Mb of traffic for

    Router G

    Massive (44%) packet loss atRouter B->Router E!

    Router E

  • 7/28/2019 Cisco Mpls -Te for Vpns

    11/41111111 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Router F

    How MPLS TE Solves the problem

    Router A sees all l inks

    Router A computes paths

    on properties other thanjust shortest cost

    No link oversubscribed!

    Router C

    Router E

    Router D

    Router G

    Router A

    Router B

    40Mb40Mb

    40Mb

    40Mb

    NodeNode Next-HopNext-Hop CostCost

    BB 1010BB

    F 30Tunnel 0

    CC 1010CCDD 2020CC

    EE 2020BB

    GG 3030Tunnel 1Tunnel 1

    OC-3

    OC-3

    DS3

    DS3

    DS3OC-3

    OC-3

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    121212 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    TE Fundamentals Building Blocks

    Path Calculation uses IGP

    advertisements to compute

    constrained paths

    RSVP/TE used to distribute

    labels, provide CAC, failure

    notification, etc.

    IGP (OSPF or ISIS) used to

    flood bandwidth information

    between routers

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    131313 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Information Distribution

    You need a link-state protocol as your IGP

    IS-IS or OSPF

    Link-state requirement is only forMPLS-TE!

    Not a requirement for VPNs, etc! Why do I need a link-state protocol?

    To make sure info gets flooded

    To build a picture of the entire network

    Information flooded includes Link,

    Bandwidth, Attributes, etc.

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    141414 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    NodeNode Next-HopNext-Hop CostCost

    BB 1010BB

    F 30Tunnel 0

    CC 1010CCDD 2020CC

    EE 2020BB

    GG 3030Tunnel 1Tunnel 1

    Router F

    Path Calculation (PCALC)

    PCALC takes bandwidth,other constraintsinto account

    Paths calculated, resourcesreserved if necessary

    End result: Bandwidth usedmore efficiently!

    40Mb

    40Mb

    OC-3

    OC-3

    DS3

    DS3OC-3

    DS3Router C

    Router E

    Router D

    Router G

    Router A

    Router B

    40Mb40Mb

    OC-3

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    151515 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Path Calculation

    What if theres more than one path that meets

    the minimum requirements (bandwidth, etc.)?

    PCALC algorithm: Find all paths with thelowest IGP cost

    1. Pick the path with the highest minimum availablebandwidth along the path

    2. Then pick the path with the lowest hop count (notIGP cost, but hop count)

    3. Then just pick one path at random

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    161616 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Path Setup

    PATH message: Can I have 40Mb along this path?

    RESV message: Yes, and heres the label to use Labels are installed along each hop

    Router FRouter B

    Router C

    Router E

    Router D

    Router G

    Router A

    = PATH messages

    = RESV messages

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    171717 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Unequal Cost Load Balancing

    IP routing has equal-cost load balancing, but not unequal cost*

    Unequal cost load balancing diff icult to do while guaranteeing aloop-free topology

    Since MPLS doesnt forward based on IP header, permanentrouting loopsdont happen

    16 hash buckets for next-hop, shared in rough (11:5 for case

    below) proportion to configured tunnel bandwidth or load-sharevalue

    Router A Router E

    Router F

    *EIGRP Has Variance, but Thats Not As Flexible

    Router G

    40MB

    20MB

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    181818 2003, Cisco Systems, Inc. All rights reserved.

    Ecosystems Seminar

    TE for VPNs

    Auto-Route

    Router As routingtable, built via

    auto-route Everything behind

    the tunnel is routed

    via the tunnel

    Tunnel1

    Router FRouter H

    Router B

    Router C

    Router E

    Router D

    Router G

    Router A

    Router 1

    NodeNode Next-HopNext-Hop CostCost

    BB 1010BB

    FF 3030BB

    CC 1010CCDD 2020CC

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