sdn-enabled carrier ethernet - · pdf filesolution technical marketing engineer: jiri...

Solution Technical Marketing Engineer: Jiri ChaloupkaArchitect and project lead: Dennis Cai

Released: 04/2016

ACE ArchitectureSDN-enabled Carrier Ethernet

ACE: Agile Carrier Ethernet

2© 2016 Cisco and/or its affiliates. All rights reserved.

• Large scale à Operational simplicity is the key, low OPEX and CAPEX

• Differentiate the service à Optimized Routing and Application-aware, network slicing (5G)

• Rapid service deployment à Fully programmable and automation

• Strict service SLA: QoS, HA• Network is simple à low OPEX and CAPEX, de-protocols

Key Characters/Requirements of the CE Network

Ultimate Goal: Simple, fully programmable, application-aware


eBGPIPv4+label

eBGPIPv4+label CSG

CSG

CSGFAN

FAN

FAN

CN-RR

RR

iBGPIPv4+label

MTG

MTG

iBGPIPv4+label iBGP

IPv4+labeliBGP

IPv4+label

iBGPIPv4+label

PANInline RR

ç next-hop-self è

PANInline RR

ç next-hop-self è

CN-ASBRç next-hop-self è

CN-ASBRç next-hop-self è

RR

AGN-RR

RR

AGN-RR

AS-B AS-A AS-C

AGN-ASBRç next-hop-self è

AGN-ASBRç next-hop-self è

Core NetworkIS-IS L2

Fixed Access NetworkIS-IS L1

Aggregation NetworkIS-IS L2

Aggregation NetworkIS-IS L2

Mobile Access NetworkIS-IS L1

LDP LSP LDP LSP LDP LSP LDP LSP LDP LSP

iBGP Hierarchical LSP iBGP Hierarchical LSPiBGP Hierarchical LSPeBGP LSP eBGP LSP

AGN-SE

Unified MPLS Transport Model Baseline


Carrier Ethernet with Open Segment RoutingAutonomic, Self-protected Transport

Service protocols

Transportprotocols

SRBGP

SDN


Applications

CLIs

Applications

APIs

APIs

Router

Apps

Router

Apps

Controller/Orchestration

Unified IP/MPLSACE (baseline)

What’sACE(AgileCarrierEthernet)?

Transport:Segment Routing

Service:BGP/EVPN + static PW

NSO WAE/PCE EPN-M

Simplified control plane (distributed on router)Centralized management and policy control

https://tools.ietf.org/html/draft-filsfils-spring-large-scale-interconnect-01


Segment Routing

• Source Routing• the source chooses a path and encodes it in the packet header as an ordered list of

segments• the rest of the network executes the encoded instructions

• Segment: an identifier for any type of instruction• forwarding or service

• In this presentation: IGP-based forwarding construct


Segment Routing – Forwarding Plane

• MPLS: an ordered list of segments is represented as a stack of labels• Segment Routing re-uses MPLS data plane without any change• Segment represented as MPLS label• Applicable to IPv4 and IPv6 address families


Segment Routing

• Source Routing• the source chooses a path and encodes it in the packet header as an ordered list of

segments• the rest of the network executes the encoded instructions

• Segment: an identifier for any type of instruction• forwarding or service

• In this presentation: IGP-based forwarding construct


IGP Prefix Segment

• Shortest-path to the IGP prefix• Equal Cost MultiPath (ECMP)-aware

• Global Segment• Label = 16000 + Index

• Advertised as index

• Distributed by ISIS/OSPF

1 2

3 4

516005

16005

16005

16005

16005

16005

160051.1.1.5/32

All nodes use default SRGB16,000 – 23,999


IGP Adjacency Segment

• Forward on the IGP adjacency• Local Segment• Advertised as label value• Distributed by ISIS/OSPF

1 2

3 4

524024

24025Adj to 5

Adj to 4



Combining IGP Segments• Steer traffic on any path through

the network• Path is specified by list of

segments in packet header, a stack of labels

• No path is signaled• No per-flow state is created• Single protocol: IS-IS or OSPF

1 2

3 4

5

16004 24045

1600424045

Packet to 5

24045Packet to 5



TI-LFA – double-segment example• To steer packets on the TI-LFA backup path:

“forward the packet on interface to R5 and push the segments {prefix-SID(R4) and adj-SID(R4-R3)}”

P-space Q-space

Default metric: 10

5

21

A Z

R3R4 34Packet to Z

prefix-SID(Z)

Packet to Z

Packet to Zprefix-SID(Z)

adj-SID(R4-R3)prefix-SID(R4)


adj-SID(R4-R3)

1000



Applications

CLIs

Applications

APIs

APIs

Router

Apps

Router

Apps

Controller/Orchestration

Unified IP/MPLSACE (baseline)

What’sACE(AgileCarrierEthernet)?

Transport:Segment Routing

Service:BGP/EVPN + static PW

NSO WAE/PCE EPN-M

Simplified control plane (distributed on router)Centralized management and policy control

https://tools.ietf.org/html/draft-filsfils-spring-large-scale-interconnect-01


xEVPN Business Advantages• All-Active (per-flow) access load-balancing• Fast convergence (link / node / MAC moves)

Business Continuity Service Robustness

• Control-plane (BGP) learning in the Core. PWs no longer used• Scalability of IP VPN. MAC address scalabilityDesigned to Scale

• Per-flow and per-service access load-balancing• PE load-balancing (BGP multi-pathing). Access / core ECMPCapEx Optimization

• Peer PEs auto-discovery. Redundancy group auto-sensing• Operational consistency with L3 IP VPN

Ease of Provision and Operation

• Support existing and new service types (E-LAN, E-Line, E-TREE, VLAN-aware bundling)Service Flexibility

• Open standard• Multi-vendor supportInvestment Protection


EVPN - RFCs/Drafts


VPWS

VPWS Signaling• LDP-based (RFC 4447)• BGP-based (informational draft)

• draft-kompella-l2vpn-l2vpn

VPWS with LDP-signaling and No auto-discovery

• Most widely deployed solution• Auto-discovery for point-to-point

services not as relevant as for multipoint

Discovery and Signaling Alternatives

16

ManualNo Auto-

Discovery

Border Gateway Protocol (BGP)

StaticNo Signaling BGP

Label Distribution

Protocol (LDP)

VPN Discovery

Signaling

Most widely deployed


VPLSVPLS Signaling

• LDP-based (RFC 4762)• BGP-based (RFC 4761)

VPLS with LDP-signaling and No auto-discovery

• Most widely deployed solution• Operational complexity for larger

deployments

BGP-based Auto-Discovery (BGP-AD) (RFC 6074)

• Enables discovery of PE devices in a VPLS instance

Discovery and Signaling Alternatives

17

ManualNo Auto-

Discovery

Border Gateway Protocol (BGP)

StaticNo Signaling BGP

Label Distribution

Protocol (LDP)

VPN Discovery

Signaling

Most widely deployed RFC

6074

RFC4761


Next-Generation Solutions for L2VPNSolving VPLS challenges for per-flow Redundancy

• Existing VPLS solutions do not offer an All-Active per-flow redundancy

• Looping of Traffic Flooded from PE

• Duplicate Frames from Floods from the Core

• MAC Flip-Flopping over Pseudowire• E.g. Port-Channel Load-Balancing does not

produce a consistent hash-value for a frame with the same source MAC (e.g. non MAC basedHash-Schemes)

PE1

PE2

PE3

PE4

CE1 CE2

Echo !

PE1

PE2

PE3

PE4

CE1 CE2Duplicate !

M1

M1

M2

PE1

PE2

PE3

PE4

CE1 CE2MAC

Flip-Flop

M1 M2


What is EVPN?• EVPN family introduces next generation

solutions for Ethernet services• BGP control-plane for Ethernet Segment

and MAC distribution and learning over MPLS core

• Same principles and operational experience of IP VPNs

• No use of Pseudowires• Uses MP2P tunnels for unicast• Multi-destination frame delivery via ingress

replication (via MP2P tunnels) or LSM

• Multi-vendor solutions

• Cisco is author of most RFCs/Drafts

EVPN-VPWS

P2P Multipoint

EVPN PBB-EVPN

EVPN RFC 7432

RFC 7623draft-ietf-bess-evpn-vpws

RFC 7432


EVPN – Ethernet VPNControl Plane/Data-plane separation

Control-Plane

EVPN(MP-BGP)

RFC7432

Data-Plane

Multi-Protocol Label Switching (MPLS)RFC7432

Provider Backbone Bridges(PBB+MPLS)

RFC7623

Network Virtualization Overlay (VXLAN, NVGRE,

MPLSoGRE)draft-ietf-bess-evpn-overlay


Unified MPLS vs. Agile Carrier EthernetUnified MPLS Agile Carrier Ethernet

Separation into IGP Domains Yes Yes

Transport Path E2E Yes Yes

Intra-Area Path Provisioning IGP/LDP IGP with Segment Routing

Inter-Area Path Provisioning BGP-3107 Programmed - Netconf/YANG, PCEP

Service Provisioning MP-BGP Programmed - Netconf/YANG & MP-BGP

Redundancy LFA/R-LFA TI-LFA

Traffic Engineering RSVP TE SR TE

Application Engineered Routing N/A Yes (with WAE integration)


Core

Metro areaSingle IGP SR domain

A

GW

GW

ACE Transport Architecture(1)Intra-domain transport

A

A

Simple Network Transport• Access node only run IGP segment routing (ospf/isis extension)• Link use IPv4 unnumbered or IPv6 to get rid of IP address management overhead• Node is plug-n-play

Self-protected and optimized • Link and node protection by segment routing TI-LFA• GW nodes redundancy by anycastSID• Shortest path, ECMPs

IPv4 unnumbered interfaces or IPv6

A

A

Network Transport Underlay


CoreMetro1 Metro2

A B

GW21 1002

GW221002

GW11 1001

GW12 1001

IGP/SR metro island

IGP/SR metro island

Core IGP

Controller Controller program/provision the inter-domain LSP with SR SID list statically or dynamically

SR label: [1001, 1002,B]

SR label: [1002, 1001, A]

SDN controlled end-to-end LSP (SR segment list)

ACE Transport Architecture (2.1)Inter-domain: End-to-End SR

router staticaddress-family ipv4 unicast

20.0.0.4/32 sid-list 1001 1002 16002

SID: 16002SID: 16001

Netconf/yangPCEP

Shortest pathLow-latency path, disjointed path …

Network Transport Underlay

draft-filsfils-spring-large-scale-interconnect


Core

Metro1

Metro2

A B

GW21 1002

GW221002

GW11 1001

GW121001

NSO

A1

CE1 CE2

GUI/CLI/REST

1. Creates L2/L3 VPN services2. Creates SR path based on local prefix-SID tableDestination = BSLA „tag“ (e.g. 1)Sid-list 1001, 1002, B

TransportControllerOption1–StaticbyNSO

ACE App


Core

Metro1

Metro2

A B

GW21 1002

GW221002

GW11 1001

GW121001

NSO

A1

CE1 CE2

XRv (PCEP)

GUI/CLI/RESTService (L2/L3VPN) + SLA

• Service provisioning on the node will trigger the request the PCEP request

• Upon receiving the request, PCEP server will program the SR-TE path: shortest path, low latency path, disjointed path per SLA tag

• Service provisioning and transport SR-TE de-couple

BGP-LS

TransportControllerOption2–XRv(PCEP)Controller


Core

Metro1

Metro2

A B

GW21 1002

GW221002

GW11 1001

GW121001

NSO

A1

CE1 CE2

WAEOSC/ODL

GUI/CLI/RESTService (L2/L3VPN) + SLA

BGP-LS

TransportControllerOption3–WAE/OSC/ODL

• Service provisioning on the node will trigger the PCEP request

• Upon receiving the request, WAE/OSC/ODL will program the SR-TE path:shortest path, low latency path, disjointed path per SLA tag

• Service provisioning and transport SR-TE de-couple


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30

Dynamic VPN instantiation of SRTE policies • CE21 advertises prefixes to PE

BGP:1.1.1.21/32,via 21


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30


• PE22 checks its policy and finds that 1.1.1.21/32 must receive low latency service

MAP: 1.1.1.21/32 in vrf BLUE must receive low latency service à tag with community (100:777)

BGP:1.1.1.21/32,via 21


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30



• PE22 tags 1.1.1.21/32 with a BGP community (e.g. 100:777)and sends to RR11


BGP:1.1.1.21/32,via 21


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30



• PE22 tags 1.1.1.21/32 with a BGP community (e.g. 100:777)and sends to RR11

• RR11 sends to PE3


BGP:1.1.1.21/32,via 21


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30

Dynamic VPN instantiation of SRTE policies • PE3 checks its policy and finds it must use a path

to BGP NH (PE22) with optimized TE Metric1

• A TE attribute-set (e.g. attr-set “LTCY”) defines Optimization Objective and Constraints

1 TE metric is used here to express link latency

MAP: Community (100:777) means “minimize TE Metric” and “compute at PCE”


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30

Dynamic VPN instantiation of SRTE policies • PE3 requests a path towards PE22 from PCE

(10)

COMPUTE: minimize TE Metric to PE22

PCreq


Vrf BLUE

Vrf BLUE

3

7

22

23

21

5

9

2 13 14

10 11

T:30

T:30

Dynamic VPN instantiation of SRTE policies • PE3 requests a path towards PE22 from PCE

(10)

• PCE computes a dynamic path with the required Optimization Objective and Constraints• Result: SID list {S5, S14, S22}

• PE3 instantiates SRTE Policy withBinding-SID: 30022

COMPUTE: minimize TE Metric to PE22

RESULT: SID list {S5, S14, S22}

PCreq/reply

BSID:30022

SID list: Segment ID list,list of segments


Dynamic VPN instantiation of SRTE policies 1.1.1.21/32; NH: PE22Received VPN label: L_VPNCommunity 100:777BG

P


Dynamic VPN instantiation of SRTE policies 1.1.1.21/32; NH: PE22Received VPN label: L_VPNCommunity 100:777BG

P

SRTE Policy to PE22:SID List {S0, S1, S2}, OIF 3Binding Label: 30022TE


Local label: 30022OIF: SRTE; Label stack {L1, L2}

Dynamic VPN instantiation of SRTE policies • TE installs SRTE Policy in FIB:

Binding-SID (e.g. 30022): push {label L1, label L2}

1.1.1.21/32; NH: PE22Received VPN label: L_VPNCommunity 100:777BG

PFI

B



Dynamic VPN instantiation of SRTE policies • TE installs SRTE Policy in FIB:

Binding-SID (e.g. 30022): push {label L1, label L2}

• TE provides theBinding-SID of the SRTE Policy to BGP

1.1.1.21/32; NH: PE22Received VPN label: L_VPNCommunity 100:777Binding Label: 30022BG

PFI

B





Dynamic VPN instantiation of SRTE policies • BGP installs best-path in FIB:

• 1.1.1.21/32 via 30022• Push VPN label and steer in SRTE Policy

1.1.1.21/32; NH: PE22Received VPN label: L_VPNCommunity 100:777Binding Label: 30022

1.1.1.21/32; recursion-via-segmentlabel L_VPN, NH via 30022


BGP

FIB


CoreMetro1 Metro2

A B

GW21 1002

GW221002

GW11 1001

GW121001

IGP/SR metro island

IGP metro islandCore IGP

Tail-f NSO Static PW provisioning by Tail-f NSOInter-domain or intra-domain

PW label: 24001

ACE Service Architecture (1): L2VPN P2P

A

CE1 CE2

In-band PW OAM

Remote-port shutdown

ServiceOverlay

Remote-port shutdown


CoreMetro1 Metro2

A B

GW21 1002

GW221002

GW11 1001

GW121001

PW label: 24001

ACE Service Architecture (2): L2VPN MP

A

CE1 CE2

EVPN Static PWStatic PW

Simple GW node redundancy solution• Transport: anycast GW label• EVPN: Static PW as EVPN virtual Ethernet

Segment

PW label: 24002

EVPN

Static PW Static

PW

Tail-f NSO

H-EVPN: Static PW provisioning in accessEVPN between service nodesVirtual EVPN ES using anycastaddress

ServiceOverlay

BD

BD BD

BD


CoreMetro1 Metro2

A B

GW21 1002

GW221002

GW11 1001

GW121001A

CE1 CE2

EVPN Static PWStatic PW

BD

EVPN

Static PW Static

PW

ServiceOverlay

All-activeusing anycast

address

Single-active (PBB-EVPN) All-active (EVPN)

Draft-sajassi-bess-pbb-evpn-anycast-ip-tunnels (need for evpn as well)

BD BD

BD


CoreMetro1 Metro2

A

GW21 1002

GW221002

GW11 1001

GW121001

Provision static PW label on both access nodes and the GW nodes

PW label: 24001

ACE Service Architecture (3): L3VPN centralized

CE1 CE2

PWHE

GW node redundancy options• Static PW terminated into PWHE or EVPN IRB interface for L3 service• CE A/A dual-homing to multiple service nodes using anycastaddress

PW label: 24002, 24003

IP-VPN

Static PW

Static PWPWHE

EVPN IRB

PWHE IRB

Default route: anycast GW

B

ServiceOverlay

Tail-f NSO

EVPN IRB

Default route: anycast GW


EVPN BGP Routes RFC7432

• EVPN defines a new BGP NLRI used to carry all EVPN routes• BGP Capabilities Advertisement used to ensure that two speakers support EVPN NLRI (per

RFC4760)

Overview

Route Type

Length

Route type specific

1 byte

1 byte

[1] Ethernet Auto-Discovery (AD) Route[2] MAC Advertisement Route[3] Inclusive Multicast Route[4] Ethernet Segment Route

EVPN NLRI

Variable


EVPN BGP route typeRoute type Usage EVPN PBB-EVPN EVPN VPWS

0x1 Ethernet Auto-Discovery (A-D) Route

• MAC Mass-Withdraw• Aliasing (load balancing)• Split-Horizon “Tagged with ESI Label Extended Community”

ü NOT used ü

0x2 MAC Advertisement Route • Advertise MAC addresses• Provide MAC / IP address bindings for ARP

broadcast suppression“Tagged with MAC Mobility Extended Community”

ü ü NOT used

0x3 Inclusive Multicast Route • Multicast tunnels used to transport Broadcast, Multicast and Unknown Unicast frames (BUM)

“Tagged with PMSI tunnel attribute” (P tunnel type & ID) – RFC6514

ü üNOT used

0x4 Ethernet Segment Route • Auto discovery of Multi-homed Ethernet Segments, i.e. redundancy group discovery

• Designated Forwarder (DF) Election“Tagged with ES-Import Extended Community”

ü ü ü


EVPN BGP Extended Community

Attribute Usage Tagged BGP route

EVPN PBB-EVPN EVPN VPWS

ESI label Extended Community

• Split-Horizon for Ethernet Segment.

• Indicate Redundancy Mode (Single Active vs. All-Active)

Ethernet A-D Route

üNot used

ü

ES-Import Extended Community

• Limit the import scope of the Ethernet Segment routes.

Ethernet Segment Route ü ü ü

MAC Mobility Extended Community

• E-VPN: Indicate that a MAC address has moved from one segment to another across PEs.

• PBB-EVPN: Signal C-MAC address flush notification

MAC Advertisement Route

ü ü Not used


E-VPN Startup Sequence (cont.)ESI Auto-Sensing

46

Segment Auto-Discovery

Ethernet Segment ID (ESI) Auto-Sensing

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

CE LACP info:LACP System Priority (2B)

e.g. 0000LACP System ID (MAC) (6B)

e.g. 0011.0022.0033LACP Port Key (2B)

e.g. 0018

ESI (10B) can be auto-generated* from CE’s LACP information àConcatenation of CE’s LACP System Priority + System ID + Port Key

Example:0000. 0011.0022.0033.0018

LACPPDU exchange

(*) ESI can also be manually configured

System Priority

2 bytes 6 bytes 2 bytes

System MAC Address Port Key


E-VPN Startup Sequence (cont.)BGP Ethernet Segment Route

47

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

PE 1 Eth Segment RouteRD = RD10ESI = ESI1

ES-Import ext. comm.e.g. 0011.0022.0033

MAC address portion of ESI (6B)

PE 2 Eth Segment RouteRD = RD20ESI = ESI1

ES-Import ext. comm.e.g. 0011.0022.0033



Redundancy Group Membership Auto-Discovery

RD – RD unique per advertising PE


E-VPN Startup SequenceDesignated Forwarder (DF) Election*

48

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

Ordered List of discovered PEs starting from zero (lowest IP add)




PE Ordered ListPosition PE

0 PE11 PE2

Modulo Operation

E-VPN ID (EVI)

EVI mod N (N = # of PEs)

(e.g. EVI mod 2)100 0101 1102 0103 1

PE Ordered ListPosition PE

0 PE11 PE2

Modulo OperationE-VPN ID

(EVI) (EVI mod 2)

100 0101 1102 0103 1

Exchange of Ethernet Segment Routes

Result of modulo operation is used to determine DF and BDF status

DF – Designated ForwarderBDF – Backup Designated Forwarder

Example:PE2 DF for EVIs 101, 103PE2 BDF for EVIs 100, 102

Example:PE1 DF for EVIs 100, 102PE1 BDF for EVIs 101, 103

(*) DF election with Service Carving shown (i.e. one DF per EVI in the segment)


E-VPN Startup Sequence (cont.)BGP Ethernet AD Routes – Per-ESI

49

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

PE 2 Eth A-D Route (Per-ESI)RD = RD20ESI = ESI1

ESI MPLS Label ext. comm.Flag = All-Active

Label (e.g. LESI21)RT ext. community

RT-a, RT-b, RT-c, RT-d




Ethernet Segment Reachability Advertisement

Per-ESIadv.


ESI MPLS Label ext. comm.Flag (e.g. All-Active)Label (e.g. LESI11)

RT ext. communityRT-a, RT-b, RT-c, RT-d

Flags– Redundancy mode - All-Active or Active-Standby

Multiple RTs – all RTs for EVIs present in the segment

ESI MPLS Label – used by local PEs for split-horizon. Downstream assigned (ingress replication) or Upstream assigned (P2MP LSP)

RD – RD unique per advertising PE


MPLS

PE1

CE1

PE2

PE3

CE3

PE4

E-VPN Startup Sequence (cont.)BGP Ethernet AD Routes – Per-EVI

50

PE 1 Eth A-D Route (Per-EVI)RD = RD-1aESI = ESI1

Label (e.g. LES11)RT ext. community

RT-a

Aliasing MPLS Label –used by remote PEs to load-balance among local PEs

PE 2 Eth A-D Route (Per-EVI)RD = RD-2aESI = ESI1

Label (e.g. LES21)RT ext. community

RT-a

RT – RT associated with a given EVI

PE3 / PE4 RIBVPN MAC ESIRT-a - ES1

Path ListNHPE1PE2




Per-ESIadv.

Per-EVI adv.

Ethernet Segment Reachability Advertisement

RD – RD unique per advertising PE per EVI


E-VPN Startup Sequence (cont.)BGP Inclusive Multicast Route

51

VPN Auto-Discovery

Multicast Tunnel ID / Endpoint Discovery

PE 1 Inclusive Multicast RouteRD = RD-1a

PMSI Tunnel AttributeTunnel Type (e.g. Ing. Repl.)

Label (e.g. XXXX)RT ext. community

RT-a

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

Tunnel Type – Ingress Replication or P2MP LSP

Mcast MPLS Label – used to transmit BUM traffic -downstream assigned (ing. repl.) or upstream assigned (Aggregate Inclusive P2MPLSP1)

PMSI - P-Multicast Service InterfaceBUM – Broadcast / Unknown Unicast / Multicast

RD – RD unique per advertising PE per EVI

RT – RT associated with a given EVI

PE 2 Inclusive Multicast RouteRD = RD-2a

PMSI Tunnel AttributeTunnel Type (e.g. Ing. Repl.)

Label (e.g. YYYY)RT ext. community

RT-a(1) Mcast MPLS label is not assigned with Inclusive Trees (P2MP LSP)


MPLS

PE1

CE1

PE2

PE3

CE3

PE4

Life of a PacketIngress Replication – Multi-destination Traffic Forwarding

52

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

VID 100SMAC: M1DMAC: F.F.F L3

L2 L5

L4

Mcast MPLS Label assigned by PE3 for incoming BUM traffic on a given EVI

PSN MPLS label to reach PE3

ESI (split-horizon) MPLS label allocated by PE2 for segment ES1

PE4 – non-DF for given EVI drops BUM traffic

PE2 – drops BUM traffic originated on ES1

PE1 receives broadcast traffic from CE1. PE1 forwards it using ingress replication – 3 copies created PE3 – as DF, it

forwards BUM traffic towards segment

During start-up sequence, PE2 sent Per-ESI Ethernet AD route with ESI MPLS label (split-horizon) (see below)

PE 4 Inclusive Multicast Route

RD = RD-4aPMSI Tunnel AttributeTunnel Type = Ing. Repl.

Label = L4RT ext. community

RT-aMcast MPLS Label – used to transmit BUM traffic -downstream assigned (for ingress replication)

During start-up sequence, PE1, PE2, PE3, PE4 sent Inclusive Multicast route which include Mcast label


ESI MPLS Label ext. comm.Redund. Flag = All-Active

Label = L5RT ext. community

RT-a, RT-b, RT-c, RT-d

ESI MPLS Label – used by local PEs for split-horizon -downstream assigned (for ingress replication)


MPLS

PE1

CE1

PE2

PE3

CE3

PE4

Life of a Packet (cont.)Unicast Traffic Forwarding

53

PE1 MAC RouteRD = RD-1aESI = ESI1MAC = M1Label = L1

RT ext. communityRT-a

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

L1

MP2P VPN Label assigned by PE1 for incoming traffic for the target EVI


PE3 forwards traffic destined to M1 based on RIB information (PE1)

PE3 RIBVPN MAC ESIRT-a M1 ES1

Path ListNHPE1

VID 100SMAC: M2DMAC: M1VID 100

SMAC: M1DMAC: F.F.F

MP2P VPN Label –downstream allocated label used by other PEs to send traffic to advertised MAC

MAC advertised by route


Life of a Packet (cont.)Unicast Forwarding and Aliasing

54

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

PE3, PE4 RIBVPN MAC ESIRT-a M1 ES1

Path ListNHPE1PE2

MPLS

PE1

CE1

PE2

PE3

CE3

PE4

L2

Aliasing MPLS Label assigned by PE2 for (ES1, EVI) pair


PE3 forwards traffic on a flow (flow 2) based on RIB information (towards PE2)

VID 100SMAC: M4DMAC: M1

L1

MP2P VPN Labelassigned by PE1 for incoming for target EVI


PE3 forwards traffic on a flow (flow 1) based on RIB information (towards PE1)

VID 100SMAC: M3DMAC: M1

During start-up sequence, PE2 sent Per-EVI Ethernet AD route (see below)

PE1 MAC RouteRD = RD-1aESI = ESI1MAC = M1Label = L1


MP2P VPN Label –downstream allocated label used by other PEs to send traffic to advertised MAC

MAC advertised by route

PE 2 Eth A-D Route (Per-EVI)RD = RD-2aESI = ESI1Label = L2


Aliasing MPLS Label –used by remote PEs to load-balance among local PEs

During start-up sequence, PE1 sent Per-EVI Ethernet AD route

VID 100SMAC: M1DMAC: F.F.F

sdn-enabled carrier ethernet - · pdf filesolution technical marketing engineer: jiri...

Documents