GVPNs: Generalized VPNs using BGP and GMPLS Toolkit

draft-ouldbrahim-ppvpn-gvpn-bgpgmpls-06.txt

Hamid Ould-Brahim (hbrahim@nortel.com)Yakov Rekhter (yakov@juniper.net)

(Editors)

Contributors

• Luyuan Fang (AT&T) • Don Fedyk (Nortel) • Peter Ashwood-Smith (Nortel) • Eric C. Rosen (Cisco) • Eric Mannie• John Drake (Boing) • Yong Xue • Riad Hartani (Caspian Networks) • Dimitri Papadimitrio (Alcatel) • Lou Berger (Movaz)

Draft Summary

• Work started in 2001 on Optical VPNs services Evolved into Generalized VPNs through time.

• The basic unit of GVPN service is a Label Switched Path (LSP) between two CEs across provider network.

• Uses GMPLS (signaling only or both signaling and routing) and BGP as the discovery mechanism.

• l1vpn is one type of GVPN services (when CE-PE interfaces are layer 1-based).

• GVPN is a port-based VPN Model.• Reuses mechanisms already defined in layer (3,2) VPNs.• Two GVPN services defined (see next slides).

Service 1: Generalized Virtual Private Wire (GVPW)

• Ability to establish private connections between CEs basic mode in the context of l1vpn.

• Connectivity is done within a pre-configured port-topology. – Controlled by the customer– Configured at the provider network level– Customer may select any “connectivity” topology within the

defined set (hub and spoke, full mesh, etc).• Service provider restricts customer’s connectivity topology

to only the one in the set defined by the customer.

ServiceProviderNetwork

PE1

PE2

PE5

PE4

PE3

PE5

P1

P5

P2

P3

P6

P7P4

CE1CE3

CE4

CE5

CE61

10.1.1.110.1.1.3

10.1.1.4

10.1.1.5

10.1.1.6

16.1.1.1

16.1.1.6

16.1.1.3

16.1.1.5

16.1.1.4

CE1CE3

CE4

CE5

CE61

Customer Connectivity Topology

Private Addresses (on both sides of CE-PE link)

On-demand private connectivity within a VPN

CE: Router,Sonet/SDH,L2 switch

Provider Addresses (for the same PE portnot visible to the CEs)

GMPLS UNI (overlay-draft)

GVPW Functions

1. Run a BGP auto-discovery mechanism– to allow the PEs to learn about the remote VPN ports and their

corresponding provider addressing.– to allow the CE to auto-learn (when needed) the set of remote CE

port addresses (to be used for signaling).

2. Once the discovery process is done, a CE initiates GMPLS path request to the attached PE for a given destination CE.

• Using exclusively private addresses.• During signaling, switch private with provider addresses (referred as

“shuffling” approach).• No need for VPN-ids in signaling between CE-PEs.

• uses existing GMPLS signaling protocol

Service 2: Generalized Virtual Private Cross-Connect (GVPXC)

• The service provider network appears as a GMPLS-enabled virtual private node – uses both GMPLS signaling and participates in

distributing customer routing enhanced mode in the context of l1vpn.

–Address the n square routing peering between CEs (across the l1vpn connections – for l1vpn)

• Transparent integration of traffic engineering within the customer network

GVPXC-A

CE1

CE2

CE4

C3

C2

C3

C4 C5CE3

C7

C1

10.1.1.1

10.1.1.2 10.1.1.3

10.1.1.710.1.1.8

Routing Adjacency

OSPF-TE/ISIS (online)

10.1.1.410.1.1.6

Generalized Virtual Private Cross-connect (GVPXC)

GVPXC is addressed within the private networkIn such a way it reflects a normal LSR within the private network.

GMPLS enabledboth at signaling and routing at CE-PE level

GVPXC Functions• Auto-Discovery mechanism

– same as GVPW model.

• Routing Considerations– Two deployments scenarios: Offline and online path computation.– For On-line path computation:

a) establish a routing adjacency with attached CEs (independent from the provider routing instance)

b) generate routing information with traffic engineering (TE) information for the set of CE-PE TE-links attached to the GVPXC, and

c) flood TE-Link routing information (such as the ones learnt from other customer network nodes) to the attached CEs using normal GMPLS routing procedures.

• The approach for distributing “private” reachability within the provider network is similar to the virtual router approach used in layer-3 VPNs.