APRICOT2014 - Advanced Topics and Future Directions in MPLS

8/10/2019 APRICOT2014 - Advanced Topics and Future Directions in MPLS

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Advanced Topics and Future Directionsin MPLS

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2014 Cisco and/or its affiliates. All rights reserved.

Agenda

IETF Update

Transport Evolution

Ethernet Virtual Private Network

Segment Routing

Summary


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IETF Update


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Internet Engineering Task Force

Responsible for MPLS standardization

Six active working groups MPLS Layer 3 Virtual Private Networks (L3VPN) Pseudowire Edge-to-Edge (PWE3) Layer 2 Virtual Private Networks (L2VPN)

Common Control and Measurement Plane (CCAMP) Path Computation Element (PCE)

Some MPLS related work also defined in IS-IS and OSPF working groups


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MPLS Working Group

Defined MPLS architecture and base protocols (LDP, RSVP-TE)

Over 130 RFCs published to date

Mature set of IP/MPLS specifications for both unicast and multicast

Areas of focus MPLS Transport Profile (MPLS-TP)

Seamless MPLS (building large scale, consolidated MPLS networks)



L2VPN WG

Mature specifications for:- Virtual Private Wire Service (VPWS): point-to-point L2 service- Virtual Private LAN Service (VPLS): multipoint-to-multipoint Ethernet serNew service definition:

- Virtual Private Multicast Service (VPMS): point-to-multipoint L2 servic Areas of focus- Enhancing VPLS - Ethernet VPN (E-VPN) and PBB Ethernet VPN (PBB-EVPN)- Optimizing E-Tree support over VPLS



ISIS WG

Responsible for IS-IS for IPCurrent proposal to do MPLS label distribution (draft-previdi-filsfils-isis-segment-routing)Similar extensions expected in the OSFP working group



IETF Summary

Rich set of MPLS specifications covering MPLS forwarding (unicast and multicast) Layer-3 and layer-2 services (unicast and multicast)

Current main focus areas: Seamless MPLS MPLS transport profile (MPLS-TP)

L2VPN enhancements (PBB-EVPN, VPMS) Segment Routing


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Transport Evolution



Industry Trends

Many transport networks still based on SONET/SDH (circuit switching technology)

Packet-based growing fast and dominating traffic mix (driven by Video, Mobile, Cloud, applicationmigration to IP)

Increased changes in traffic patterns (mobility, cloud)

Transport networks migrating to packet switching for Bandwidth efficiency (statistical multiplexing) Bandwidth flexibility (bandwidth granularity, signaling)

Packet Network(MPLS-TP)

Transport Network(SONET/SDH)

Packet Network(IP/MPLS)



Packet Transport Requirements

Connection-oriented packet-switching technology

Point-to-point (P2P) and point-to-multipoint (P2MP) transportpaths

Separation of control and management planes from dataplane

Deployable with or without a control plane

Should retain similar operational model of traditional

transport technologiesMulti-service (IP, MPLS, Ethernet, ATM, FR, etc)

Should support bandwidth reservation

Support for 1:1, 1:n, 1+1 protection with similar techniques totraditional transport technologies

Support for In-band OAM



MPLS Transport Profile

Extends MPLS to meet packet transport reqIdentifies subset of MPLS supporting traditirequirementsData plane Bidrectional P2P and unidirectional P2MP LSP ( In-band associated channel (G-Ach / GAL)Control plane Static Dynamic (GMPLS)OAM In-band

Continuity check, remote defect indication Connectivity verification and route tracing Fault OAM (AIS/LDI, LKR) Performance managementResiliency 50ms switchover Linear protection (1:1, 1+1, 1:N) Ring protection

MPLS ForwardingP2P / P2MP LSP

Pseudowire

ArchitectureOAMResilicency

GMPLS

MPLS

Newextensionsbased ontransport

requirements

Existing functionality meeting

transport requirementsExisting functionality

prior to MPLSTransport profile

MP2P / MP2MP LSPIP forwarding

ECMP

Transport Profile



MPLS Transport and Service Options

IP/MPLS (LDP/RSVP-TE/BGP) MPLS-TP (Static/RSVP-TE)

MPLS Forwarding

IPv4 Multicast

IPv4 IPv6

Transport

IPv4 VPN IPv6 VPN VPMS VPWS VP

Services (clients)

MPLS-TP currently focuses on Layer-2/1services


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MPLS-TP Components

Bi-directional,co-routedLSPsStatic LSPQoS

CC/RDIOn-demandCVRoute Tracing

AIS/LDI/LKRCFI (PWStatus)

ForwardingPlane

OAM

Linearprotection (1:1,1+1, 1:N)Reversion

Wait-to-restoretimer

Protection

Eth ATMTDMSinteIP/M

Se

StaticDynamic(GMPLS)

ControlPlane


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Multi-layer Routing (nLight Use Cases)

Optical Domain

R1 R2 R3

R1 R2

R3

Path Diversity

Disjoint paths

Disjoint paths

Dynamic Path Setup

PacketDomain

Optical Domain

R1

PacketDomain

R2

R1 R2

Signaledlambda

Signaledlambda


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GMPLS Introduction

Generalized control plane for different types of network devices Packet-Switch Capable (PSC) Layer-2 Switch Capable (L2SC) Time-Division-Multiplex Capable (TDM) Lambda-Switch Capable (LSC) Fiber-Switch Capable (FSC)

Two major models: peer (NNI) and overlay (UNI)

Different label formats depending on network type

Based on initial RSVP-TE, OSPF-TE and ISIS-TE extensions

Strict separation of control and forwarding planes

Supports bi-directional LSPs

IP based control plane

No IP based forwarding plane (no LDP)


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GMPLS UNI Reference Model (IP+Optical)

Control plane interface Client: UNI-C (packet)

Network: UNI-N (optical)

Separate packet and optical routing domains

Optical topology known to UNI-N but not to UNI-C

UNI-C initiates LSP signaling

UNI-N performs path computation through opticaldomain

Common address space between UNI-C andUNI-N to enable signaling

UNI honors administrative boundaries whileallowing controlled interaction

UNI-C

UNI-N

UNI Head

RSVPRSVP

Forwarding plane

Control plane


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GMPLS UNI Dynamic Path Setup

Router can signal a path dynamicthrough an optical (ONS 15454) using GMPLSRouter initiates signaling

ROADM computes path and signoptical path

LSP state drives controller and ph

interface state on routerSupport for HA including ISSU

Router interface is fully layer-3 a2 capable (including bundling)

Router interface may or may not

Packet

Domain

Optical Domain

R1

PacketDomain

R2

R1 R2

Signaledlambda

Signaledlambda


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Path Computation and Signaling

UNI-C (Head)

Initiates signaling (default lambda) No explicit path (ERO) defined / signaled Signaling initiated towards remote UNI-C (optical loopback or optical link address) Bi-directional path (upstream and downstream labels)

UNI-N Arrival of PATH message without ERO triggers path computation to destination acros

optical domain Establishment of optical path (trail) required for UNI signaling to proceed


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Signaling Path Setup

Opticalimpairment check

UNI PATH(upstream label = lambda)


UNI-C UNI-CUNI-NUNI-N

UNI PATH(upstream label = default lambda)

1

2

3Trail Downstream PATH

Trail Upstream PATH

Trail Downstream RESV

Trail Upstream RESV

UNI PATH ERROR(upstream label = lambda)


6Trail established

8

Tunnelestablished

UNI RESV(Label = lambda)



7

5 Trail established


Per-hop opticalparameters

4

Headinitiatestunnel

signaling

Optical pathcomputation, trailsignaling initiated


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GMPLS UNI Diverse Path Setup

Router head can signal requirementsfor path diversity against one or morespecific LSPs

ROADM includes path diversityrequirements in path computation

Source and destination of signaledLSP may differ from LSP from which

diversity is required

R1 R2

R1 R2

Disjoint paths

Disjoint paths


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Diverse Path Computation and Signaling

UNI-C (Head)

Initiates signaling (default lambda) No explicit path (ERO) defined/signaled LSP exclusions (XRO) signaled to enable path diversity Exclusions can be strict (MUST exclude) or best effort (SHOULD exclude) Signaling initiated towards remote UNI-C (optical loopback or optical link address) Bi-directional path (upstream and downstream labels)

UNI-N Arrival of PATH message without ERO triggers optical path computation to destinatio

across optical domain LSP exclusions used as additional input for optical path computation Establishment of optical path (trail) required for UNI signaling to proceed


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Signaling Diverse Path Setup



UNI-C UNI-CUNI-NUNI-N

UNI PATH(upstream label = default lambda)

1

Headinitiatestunnel

signalingincluding

LSPexclusion

2

Optical path computationsubject to LSP exclusions,

trail signaling initiated

3Trail Downstream PATH

Trail Upstream PATH

Trail Downstream RESV

Trail Upstream RESV

UNI PATH ERROR(upstream label = lambda)


6Trail established

8

Tunnelestablished




7

5 Trail established

Per-hop optical

parameters

4




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MPLS-TE and GMPLS Co-existence

Router would have two RSVP neighbors ifpacket network runs MPLS-TE on DWDM

interface,RSVP neighbor over physical interface forMPLS TE signaling

RSVP neighbor over controller for GMPLSsignaling

Separate RSVP refresh timersHigh frequency for MPLS TE signaling

Low frequency for GMPLS signaling(lowest 232 ms or ~1.6 months)

Opti

R1

Signaledlambda

RSVP

RSVP


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Ethernet Virtual Private Network


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Motivation

L2VPN (VPLS) used as data centerinterconnect (DCI) solution

Technology evolution requirements Multi-homing Scale (MAC-addresses, Number of Service Instances Load balancing Optimal Forwarding Multicast optimization Multi-tenancy

Enhancements bring benefits to otherVPLS applications

Business services Mobile backhaul

SP DC1

Ent DC1

SP NGNDCPE

DCPE

DCEDCE

PE

CE

Enterprise DCI back

Standalone DCI


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E-VPN At A Glance

MAC addresses learned in data-plane towardaccess as before

Treat MAC addresses as routable addresses anddistribute them in BGP over MPLS/IP network

Receiving PE injects these MAC addresses intoforwarding table along with its associatedadjacency

When multiple PE nodes advertise the sameMAC, then multiple adjacency is created for thatMAC address in the forwarding table

When forwarding traffic for a given unicast MACDA, a hashing algorithm based on L2/L3/L4 hdris used to pick one of the adjacencies forforwarding

Full-Mesh of PW no longer required !!

BGP

PE P

PE P


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E-VPN Broadcast Example (e.g. ARP)

Host M1 sends a message with MAC SA = M1 and MAC DA=bcast

PE1 learns M1 over its Agg2-PE1 AC and distributes it via BGP to other PEdevices

All other PE devices learn that M1 sits behind PE1

PE1

PE2 PE4

PE3

AGG1

AGG2

AGG3

AGG4

AGG5

AGG6

MH-ID=1

MH-ID=3

MH-ID=2

C-MAC1

C-M

iBGP L2-NLRI

next-hop: n-PE1

BGP

M1

M


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E-VPN Unicast Example

Host M2 sends response with MAC SA = M2 and MAC DA = M1

PE4 learns M2 over its Agg5-PE4 AC and distributes it via BGP to other PE devices

PE 4 forwards the frame to PE1 since it has learned previously that M1 sits behind PE1

All other PE devices learn that M2 sits behind PE4

PE1

PE2 PE4

PE3

AGG1

AGG2

AGG3

AGG4

AGG5

AGG6

MH-ID=1

MH-ID=3

MH-ID=2

M1

iBGP L2-NLRI

next-hop: n-PE4


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Ethernet Encapsulation Evolution

B-DAB-SA

B-TAG

I-TAGC-DAC-SA

S-TAGC-TAG

Payload

FCS

C-DAC-SA

S-TAGC-TAG

Payload

FCS

C-DAC-SA

Payload

FCS

802.1ahPBB802.1ad

PB

802.1adPB

802.1Q

802.1Q802.3

802.3

Service Instances

(VID)

212 =4,096

Service Instances(I-SID)

224 =16,777,216

C-DAC-SA

C-TAG

Payload

FCS

Service Instances

(VID) 212 =4,096

C-DA: Customer dest addrC-SA: Customer src addrC-TAG: Customer tag

S-TAG: Service tag

B-DA: Backbone dest addrS-SA: Backbone src addrI-TAG: Service instance taVID: VLAN identifier (parI-SID: Backbone service in(part of I-TAG)

PB: Provider Bridges

PBB: Provider backbone b


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Provider Backbone Bridges Ethernet VirtuPrivate Network (PBB-EVPN) Solution Overview

Advertise local B-MAC addresses in BGP to allother PEs that have at least one VPN incommon just like E-VPN

Single B-MAC to represent site ID

Can derive the B-MAC automatically fromsystem MAC address of LACP

Build a forwarding table from remote BGPadvertisements just like E-VPN (e.g.,association of B-MAC to MPLS labels)

PEs perform PBB functionality just like PBB-VPLSC-MAC learning for traffic received from ACsand C-MAC/B-MAC association for trafficreceived from core

PE2

PE1LACP

CE1

MPLS

BE B

B-MAC = Site ID

B-MAC Routes


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MAC Address Scalability

BGP MAC Advertisement Route Scalability Multiple orders of magnitude difference between C-MAC & B-MAC addresses

C-MAC Address Confinement With data plane C-MAC learning, C-MACs are never in RIB and are only present in FIB for acti

flows Whereas, with control plane C-MAC learning, C-MACs are always in RIB and maybe also in FI

WAN

DC Site 1

DC Site 2DC SiteN

O(1M) C-MAC

O(100) B-MA


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Comparison of L2VPN SolutionsVPLS E-VPN PBB-E

All-Active Redundancy

Flow Based Load Balancing No Yes Yes

Flow Based Multi-pathing No Yes Yes

Geo-redundancy and Flexible Redundancy Grouping No Yes Yes

Simplified Provisioning and Operation

Core Auto-Discovery Yes Yes Yes

Access Multi-homing Auto-Discovery No Yes Yes

New Service Interfaces No Yes Yes

Optimal Multicast with LSM

P2MP Trees Yes Yes Yes

MP2MP Trees No Yes Yes

Fast Convergence

Link/Port/Node Failure Yes Yes YesMAC Mobility Yes Yes Yes

Avoiding C-MAC Flushing No No Yes

Scalable for SP Virtual Private Cloud Services

Support O(10 Million) MAC Addresses per DC No No Yes

Confinement of C-MAC Learning No No Yes

Seamless Interworking(TRILL/802.1aq/802.1Qbp/MST/RSTP

Guarantee C-MAC Transparency on PE No No Yes


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Segment Routing


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Overview

Simple routing extensions (IS-IS / OSPF)

Increased network scalability and virtualizationUse packet encapsulation to reduce network state

Close integration between applications and network Highly programmable Highly responsive

Data plane agnostic (MPLS, IPv6)

draft-previdi-filsfils-isis-segment-routing


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Segment Routing

Forwarding state (segment) is established by IGP

LDP and RSVP-TE are not required Agnostic to forwarding dataplane: IPv6 or MPLS

MPLS Dataplane is leveraged without any modification push, swap and pop: all what we need segment = label

Source Routing source encodes path as a label or stack of segments two segments: node or adjacency


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MPLS Control and Forwarding Operation withSegment Routing

PE1 PE2

IGP PE1 PE2

Services

IPv4 IPv6IPv4VPN

IPv6VPN VPWS VPLS

PacketTransport

LDP

MPLS Forwarding

RSVP BGP Static IS-IS OSPF

Ncf

Idf

BGP / LDP

d


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Adjacency Segments

Nodes advertises adjacency label per link simple IGP extension

Only advertising node installs adjacency segment in data plane

Enables source routing along any explicit path (segment list)

B C

N O

Z

D

P

A

9101

9105

9107

9103

9105

9101

9105

9107

9103

9105

9105

9107

9103

9105

9107

9103

9105

9103

9105

9105

N d S


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Node Segment

Nodes advertise a node segment simple IGP extension

All remote nodes install node segment ids in data plane

A packet injected

with top label 65 via IGP short

A B C

Z

D

65

FEC Zpush 65

swap 65to 65

swap 65to 65 pop 65

Packetto Z

Packetto Z

65

Packetto Z

65

Packetto Z

65

Packetto Z


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A t t d & G t d FRR


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Automated & Guaranteed FRR

IP-based FRR is guaranted in anytopology

2002, LFA FRR project at Cisco draft-bryant-ipfrr-tunnels-03.txt

Directed LFA (DLFA) is guaranteedwhen metrics are symetric

No extra computation (RLFA)

Simple repair stack node segment to P node adjacency segment from P to Q

Backbone

C1

E1

E3E2

Node segmentto P node

Default metric

LFIB ith S g t R ti g


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LFIB with Segment Routing

LFIB populated by IGP (ISIS / OSPF)

Forwarding table remains constant(Nodes + Adjacencies) regardless ofnumber of paths

Other protocols (LDP, RSVP, BGP)can still program LFIB

PE

PE

PE

PE

InLabel

OutLabel

OutInterfa

L1 L1 Intf

L2 L2 Intf L8 L8 Intf

L9 Pop Intf

L10 Pop Intf Ln Pop Intf

NodeSegmentIds

AdjacencySegmentIds

Application controls net ork deli ers


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Application controls network delivers

Path ABCOPZ is ok. I account the BW.Then I steer the traffic on this path

FULL66

68

Tunnel AZ onto{66, 68, 65}

The network is simple, highly programmable and responsive to rapid changes

2G from A to Z please


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Simple Disjointness


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Simple Disjointness

Non-Disjoint Traffic

A sends traffic with [65]Classic ecmp a la IP

Disjoint Traffic A sends traffic with [111, 65]Packet gets attracted in blue planeand then uses classic ecmp a la IP

CoS based TE


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CoS-based TE

Tokyo to Brussels data: via US: cheap capacity VoIP: via Russia: low latency

CoS-based TE with SR IGP metric set such as

> Tokyo to Russia: via Russia > Tokyo to Brussels: via US > Russia to Brussels: via Europe

Anycast segment Russia advertised by Russia corerouters

Tokyo CoS-based policy Data and Brussels: push the node segment to Brussels

VoIP and Brussels: push the anycast node to Russia, pushBrussels

Node segmenNode segme


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Summary

Summary


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Summary

New MPLS enhancements focus on Increased deployment scale (unified MPLS) Packet transport extensions (MPLS Transport Profile) IP+Optical integration (GMPLS) L2VPN (VPLS) efficiency and scaling (PBB-EVPN) Highly scalable, programmable forwarding plane (Segment Routing)

New MPLS extensions to enhance Packet transport (MPLS-TP) Optical transport (GMPLS UNI)

PBB-EVPN defines BGP extensions to enhance scale and resiliency of existing VPLSdeployments and meet data centers requirements

Segment routing provides a control plane alternative for increased network scalability anvirtualization

PBB-EVPN: A Closer Look


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PBB-EVPN: A Closer Look

DF Election with VLAN Carving Prevent duplicate delivery of flooded frames. Uses BGP Ethernet Segment Route. Non-DF ports are blocked for flooded traffic

(multicast, broadcast, unknown unicast). Performed per Segment rather than per (VLAN,

Segment).

Split Horizon for Ethernet Segment Prevent looping of traffic originated from a multi-

homed segment.

Performed based on B-MAC source address ratherthan ESI MPLS Label.

Aliasing PEs connected to the same multi-homed Ethernet

Segment advertise the same B-MAC address. Remote PEs use these MAC Route advertisements

for aliasing load-balancing traffic destined to C-MACsreachable via a given B-MAC.

PE

PE

PE

PE

PE

PE

B- MAC

B-MAC

PBB-EVPN: Dual Homed Device


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PBB EVPN: Dual Homed Device

Each PE advertises a MAC route per Ethernet Segment (carries B-MAC associated with Ethernet Segment). Both PEs advertise the same B-MAC for the same Ethernet Segment.

Remote PE installs both next hops into FIB for associated B-MAC. Hashing used to load-balance traffic among next hops.

PE1 MAC Routes: Route: RD11, B-MAC1, RT2, RT3

PE2 MAC Routes: Route: RD22, B-MAC1, RT2, RT3

VPN B-MAC

RT3 B-MAC1

RT3 B-MAC1

RT2 B-MAC1 RT2 B-MAC1

VPN B-MAC

RT3 B-MAC1

RT2 B-MAC1

PE1

PE2

VLAN 2, 3

VLAN 2,3

B-MAC1

PE3

MPLS/IP


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APRICOT2014 - Advanced Topics and Future Directions in MPLS

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Transcript of APRICOT2014 - Advanced Topics and Future Directions in MPLS