Transcript PRESENTATION TITLE - By [Author Name] [email id]

MS-PWs: A Small Step for Pseudowires,
A Giant Leap for Metro Convergence?
Jeff Sugimoto - Nortel
[email protected]
PW,
MPLS
Metro A
PW,
MPLS
MPLS,
2547,
PW
WAN
2
Metro B
Network Evolution
Legacy
Leased Line Access
Service
Edge
Converged
BroadbandPacket
Access
Access
MPLS WAN
MSE
L2 Access
> Network simplification & streamlining
•
•
•
•
Consistent Network for New and Legacy Services
Collapse Operational Groups
Standardize on Ethernet Interfaces, including the MSE
Dynamically Provision & Resize Transport Tunnels, Services
> Transport Efficiency Gains
• Peel out data services from fixed size TDM circuits
3
Driving Packet
Convergence in
the Metro
Why PWs for Packet Convergence?
> Enable Service, Network consolidation
• Multi-service
• Transport Agnostic
• Commonality with the WAN
> Feature Rich - Inherits the Properties of the MPLS Tunnel Layer
•
•
•
•
Dynamically Provision & Resize Transport Tunnels, Services
OAM (LSP-PING, VCCV, Status TLV)
Resiliency (FRR, Global Repair, IP)
Traffic Engineering
> Service Rich – VPWS, VPLS
> Safe technology direction
• Standards in Place
• Broad Industry Adoption
4
Typical Deployment Models
VRF
ATM
Frame
Ethernet
MPLS Metro
L3 VPN
MSE
1
VRF
2
ATM
3
MPLS WAN
Frame
Inter/intra
provider
bound
Ethernet
1. Local backhaul to an MSE service
• Psuedowire access to L2 VPN, L3 VPN, Internet access
2. Local L2 transport
• Pseudowires/VPLS originates and terminates in the MPLS
access network
3. End to End Layer 2 transport
• Pseudowires provides transport end to end across the network
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Deployment models
Network view
Metro-Access
Interconnection
Use Case
Metro A
Core
Metro B
Inter-Provider
Use Case
Provider
A
Provider
B
6
Why not just re-use existing PW/MPLS Technology?
Metro A
WAN
Metro B
MPLS Network
10,000s devices
Challenges
• PWE3 Control Scaling
• PSN Scaling
• PSN Interoperability
• Authentication/Security
• Traffic Engineering & QoS
• Discovery/Provisioning
• Increased OPEX, CAPEX?
Metro-Access Interconnection Use Case
?
Provider
A
Provider
B
Inter-Provider Use Case
7
Motivations for Multi-Segment PWs
Metro-Access Interconnection Use Case
MS-PWs Enable
WAN
Core
Metro A
Metro B
• Limit Mesh to Domain
• Fewer PSN Tunnels
• Manageable Control
Ultimate-PEs
Switching PEs (S-PE)
U-PEs
• Different PSN Technologies
(U-PEs)
• Dry-Martini like MAN
• PSN Conversion at S-PEs
• Authentication at Boundary
Provider
Provider
• Low Cost U-PEs
A
B
Inter-Provider Use Case
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MS-PW Standardization Progress
Working Group Drafts - IETF PWE3
> MS-PW Requirements - draft-ietf-pwe3-ms-pw-requirements
• Contributions from a number of Service Providers
> Manual Configuration of MS-PWs draft-ietf-pwe3-segmented-pw
• Manual stitching of PW Segments in the S-PEs
• Interworking different PW Segments – e.g. static to dynamic, MPLS to L2TP
> Dynamic Placement of MS-PW - draft-ietf-pwe3-dynamic-ms-pw-00.txt
draft-balus-bocci-martini-dyn-ms-pwe3-00.txt just submitted as WG document
• No S-PE provisioning, automatic selection of the next PW Segment
• 1:1 Protection, Re-routing around the point of failure
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Why Extend Existing PW Procedures?
Key Principles – draft-balus-bocci-martini-dyn-ms-pwe3
> Operational Consistency, Familiarity with SS-PWs
•
•
Same Service Management, Provisioning Models
OSS Touches at only U-PEs
> Generalized Solution (SS/MS) as a Super Set of Existing Procedures
•
•
•
Existing PW Implementations, Deployments based on LDP Signaling
Re-use Signaling Procedures, Addressing
Minimal Changes (i.e. new addressing) to satisfy the MS-PW Requirements
> Address Customer Use Cases
> Easily applicable to existing LDP-VPLS Implementations
Small Addition to Existing PWs minimizes the Implementation Effort.
Enables Fast Track Technology Expansion.
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Building Blocks: from Single to Multi-Segment PWs
LDP
PWs Setup and Maintenance
• Define Multi-service Transport over PSN
• Signaling L2 FEC using LDP
draft-ietf-pwe3-control-protocol
• Scope is one network domain (WAN)
PE1
SS-PW
PE2
P
VF
VF
L2FEC
VF = Virtual Forwarder
SP = Switching Point
MS-PW
LDP
Multi-Segment PWs
• Segmentation of Control and Data Plane
• Adds Service (to Tunnel) Label Switching
• Build a Virtual Circuit across Multiple Domains
• Enabler for different PSN technologies
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LDP
U-PE1
S-PE
VF
SP
L2FEC
U-PE2
VF
Segmented PW Model - draft-ietf-pwe3-segmented-pw
Manual Configuration:
• PW X maps to PW Y
• Service Label Switching
SS-PW
SS-PW
T-PE 1
S-PE
VFx
SP
T-PE 2
VFy
LDP
LDP
PW X
PW Y
Useful for Interworking between Static PW, E-LDP-based (FEC
128, 129), different PSN types – e.g. MPLS, L2TP
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MS-PW Information Model - draft-ietf-pwe3-dynamic-ms-pw-00.txt
Unique Identification of PW Endpoint
LSPa12 = (AGI, TAII2, SAII1)
MS-PWa
LSPa21 = (AGI, TAII1, SAII2)
SS-PW
SS-PW
T-PE 1
S-PE
VFx
SP
LDP
Unique Endpoint ID
• AII11 = Global ID-Prefix1-AC ID11
T-PE 2
VFy
LDP
Unique Endpoint ID
• AII21 = Global ID-Prefix2-AC ID21
No Provisioning Required
• Automatic Selection of the next SS-PW
• Service Label Switching
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Identical Service
Management for both SS/MS-PWs
Generalized Signaling Procedures (SS/MS-PWs)
draft-ietf-pwe3-dynamic-ms-pw-00.txt
1. T-PE1 (IP1) provisioned with
•
AGI = 40
•
SAII (AC ID) = 100
•
TAII (AC ID) = 200
•
Destination PE = IP2
1’. T-PE2 (IP2) provisioned with
•
AGI = 40
•
SAII (AC ID) = 200
•
TAII (AC ID) = 100
•
Destination PE = IP1
TAII = AS#-IP2-200
4. On LM receipt:
... check TAII against
“routing table”. No full
match on “local i/f”.
Longest match =>NSH
2. Before sending LM:
… check TAII against
“routing table”. No full
match on “local i/f”.
Longest match => NSH
(next signaling hop)
T-PE1
22.
S-PE
SP
VF
LDP1
6. On LM receipt:
… check TAII against
“routing table”. Full
match on “local i/f”
implies T-PE.
P
P
30. T-PE2
VF
LDP2
3. SS-PWa LSP Fwd
5. SS-PWb LSP Fwd
8. SS-PWa LSP Rev
7. SS-PWb LSP Rev
Same Service Provisioning for SS/MS-PWs,
in-line w/ existing PW Technology
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MS-PWs Enable Technology Options for Individual PSNs
S-PE
U-PEs
PW over
PBT
S-PE
PW over MPLS
(RSVP-TE/LDP)
PW over
PBT
U-PEs
> MS-PWs enable convergence of the service layer across the network
> Architecture separates service layer from tunnel layer
• MS-PWs are transparent to tunnel layer functionality
• Trunks between x-PEs may be setup using LDP, RSVP-TE, GMPLS
> Provider Backbone Transport (PBT) – Ethernet-based Trunks
• Ethernet instantiation of “Dry-Martini - see draft-fedyk-gmpls-ethernet-ivl-00.txt
Revenue Generating Service (PWs) decoupled from PSN Technology
• PSN choices should be driven by business model, cost target, use case
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MS-PW Application: Inter-Provider
Multi-segment PWE3 End-to-end
U-PE
MD-5 Authentication
Provider
A
Dominant Attribute
• Operational Simplicity
• End to End Provisioning
S-PE
U-PE
S-PE
Inter-provider options
S-PE
S-PE
S-PE
Dominant Attribute
• Control
• Mask addressing
scheme
Provider
B
U-PE
Multi-segment PWE3
SS-PW
Interworking,
Static16Provisioning
MS-PW Application: (H)VPLS
MTU-s
MTU-s
Metro
Enable Distributed VPLS
• Complements HVPLS technology
• VSI on S-PE only if 2+ PWs are required
• MAC Learning only on T-PE
S-PE1
PE-rs
• Inter-Provider VPLS
• Transparent to existing VPLS
Provisioning, A/D Procedures
S-PE3
MTU-s
Core
Provider A
Provider
B
S-PE2
S-PE1
PE-rs
Metro
PE-rs
S-PE4
MTU-s
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= T-PE function
= S-PE function
= Virtual Switch Instance
= MS-PWs between VSIs
= SS-PWs between VSIs
Summary
> The Move to Packet based Infrastructure underway in the Metro
• … one network to handle new and legacy services
> Pseudowires provide an Ideal Framework
• … but new end-to-end MPLS Paradigms provide New Challenges
> Multi-Segment Pseudowires address SS-PW Challenges
• … Scalability, PSN Interoperability, Low Cost Edge (MTU/DSLAM)
MS-PW Provides enables Service Convergence while allowing cost
effective technology choices for Individual PSN domains
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MS-PW
MS-PW
MPLS,
2547,
MS-PW
MPLS
WAN
Metro A
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Metro B