Hybrid Virtual Private LAN - - PowerPoint PPT Presentation

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Hybrid Virtual Private LAN

<draft-lee-ppvpn-hybrid-vpls-00.txt>

Contributors: Cheng-Yin.Lee@alcatel.com, Sasha.Cirkovic@alcatel.com, Jeremy.deClercq@alcatel.be Muneyoshi Suzuki suzuki.muneyoshi@lab.ntt.co.jp Siamack Ayandeh sayandeh@txc.com Atsushi Iwata iwata@ccm.CL.nec.co.jp Jamal Hadi Salim <hadi@zynx.com

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Motivation

• minimal impact on existing provider’s network

infrastructure (PEs, Ps, L2PE) and CEs

• Bridging of customer’s traffic shall be performed in a

scalable manner for many customers and sites spanning LAN/MAN/WAN

• A customer’s L2VPN control and forwarding shall not

impact other customers

• Does not make it difficult to offer service with SLAs
• Shall meet majority of end customers requirements now,

while PE-based VPLS, would take time to be standardized, experimented with, and more challenging to scale for many emulated LANs and sites spanning WAN

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Goal

• Specify interoperable mechanisms (new and

as much as possible leverage existing technologies) for Hybrid VPLS

– Specify interoperation of CLEs and PEs as well as PEs and PEs, including mechanisms to reduce provisioning – describe interoperation of CEs and CLEs (to be compliant with existing IEEE specifications)

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Context of proposal

PE/L2PE- based CE/CLE

• based

site-to-site IPsec VPNs RFC 2547 VR PE- based VPLS Martini L2VPN CE-based VPL

Layer 3 Layer 2

Hybrid VPLS

DTLS

Note: CLE – Customer Located Equipment (Provider owned) PE-based VPLS – PW and bridging at PEs CE-based VPL – PW and bridging at CEs/CLEs Hybrid VPLS – PW at PEs, bridging at CLEs (VLAN tags used as mux ID between CLE-PE)

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CLE1 PE1 CLE5 CLE2 PE3 PE2 PE4

CLEs connected by point to point Ethernet (appear as virtual port to CLEs) P2p Ethernet provisioned at PEs by provider - trivial provisioning at CLEs, hub CLEs

• nly need to know number of remote sites

A CLE bridges traffic from one virtual port to another, no bridging on PEs in the provider’s network.

Building an emulated LAN using multiple point to point Ethernet

Eth Eth

Eth

Provider’s Network

Emulated LAN

AC AC P2p EthoPSN

CE1

Eth Eth

CE2

Eth Eth Customer Premises Customer Premises

P2p EthoPSN

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Service Delimiters

• Service delimiter between CE & CLE

– Ethernet frame (multi-point switching)

• Service delimiter between CLE & PE

– Multiplexing ID (e.g. VLAN tag, Stacked VLAN tag, MPLS VC) and

Note: In the case of connection to one remote CLE only, Mux ID is not necessary

– Ethernet frame (p2p “cross-connect”)

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CLE1 PE1 CLE5 CLE2 PE3 PE2 PE4

Multiplexing ID has local significance between CLE and PE only If the same access link is used to connect to each remote site, need to identify the different p2p Ethernet at access link with multiplexing identifiers e.g. VLAN/Stacked VLAN tags

Multiple p2p Eth over an access link

Eth Eth Eth Provider’s Network

P P P Q A A

P2P EthoPSN

A P P Q Q A A B B B

CE1 CE2 CE5

Eth Eth P2P EthoPSN Eth Customer Premises Customer Premises

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CLE1 PE1 CLE5 CLE2 CE4 CE3 PE3 PE2 PE4

Peering IP routers with different access links over a broadcast network.

All other CEs sees CE3 on a broadcast network and can peer with CE3 over the emulated LAN

Connect CE3 via a p2p IPoPSN to the emulated LAN If a new CE4 router is added, CE4 can peer with other CEs with one AC connected to the emulated LAN

Peering CE Routers over an emulated LAN

Eth Eth

Eth PSN P2P EthoPSN

FR

CE1 CE2 CE1 CE5

IPoPSN

Broadcast network

P2P EthoPSN

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Service Delimiters

• Service delimiter between CE & CLE

– Ethernet frame (multi-point switching)

• Service delimiter between CLE & PE

– Homogeneous p2p

• Multiplexing ID (e.g. VLAN tag, Stacked VLAN tag, MPLS VC)

Note: In the case of connection to one remote CLE only, Mux ID is not necessary

• Ethernet frame (p2p switching)

– Heterogeneous p2p

• Multiplexing ID
• IP packet (IP address <-> link layer address mapping)

– Alternative 1: map at CE (mp L3 switching at CE) – Alternative 2: map at CLE (p2p switching at PE) – Alternative 3: map at PE (mp L3 switching at PE)

• Service delimiter between CE & PE

– IP packet

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Motivation for Peering CE routers over an emulated LAN (with different access links)

• Reduce error prone provisioning at CE routers
• If a new CE4 router is added, CE4 can peer with
• ther CEs with one AC connected to the emulated

LAN

• Reduces link state database (cf peering CEs over

many p2p links or over different subnets)

• Reduces routing control messages
• Forwarding optimality no worse than connecting

CEs in different subnets

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Next steps

• Select mechanism(s) to automate trivial

provisioning at CLEs, reduce provisioning

• f PEs for Hybrid VPLS
• Separate draft for heterogeneous PW, PW

and router peering mechanisms?

• Evaluate need and issues of split horizon

forwarding vs spanning tree

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Backup slides

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CLE1 PE1 CLE5 CLE2 CLE4 CLE3 PE3 PE2 PE4

If a different access link is used to connect to each remote site (e.g. at CLE5), or CLE2 tags the traffic from different CE2 ports, no changes required at CLEs, no need for multiplexing identifier at access network

• therwise if only one physical link is connected to the network, a multiplexing

identifier is required

Using multiple access links or additional ports at CE/CLE

Eth Eth Eth Eth Eth

PSN

Broadcast domain

CE2 CE5

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CLE1 PE1 CLE5 CLE2 CE4 CE3 PE3 PE2 PE4

CE and CLE Bridges may have different access links (e.g. Eth and FR) Connect CE3 via a p2p EthoPSN to the emulated LAN CE3 switches/bridges traffic as defined by existing specifications

CE Bridges with different Access Links

Eth Eth

Eth PSN P2P EthoPSN

FR

CE1 CE2 CE1 CE5

P2P EthoPSN

Emulated LAN

P2P EthoPSN