BGP based Auto-Discovery Mechanism for Optical VPNs - - PowerPoint PPT Presentation

“BGP based Auto-Discovery Mechanism for Optical VPNs”

<draft-fedyk-bgpvpon-auto-00.txt>

50th IETF, Minneapolis, March 2001

Don Fedyk Hamid Ould-Brahim Peter Ashwood-Smith

(Nortel Networks)

Yakov Rekhter

(Juniper Networks)

Eric C. Rosen

(Cisco Systems)

Motivations/Requirements

• Define a BGP based auto-discovery mechanism which

allows client devices (CDs), members of the same VPN to discover themselves and to request CD-to-CD

• ptical connections across a service provider optical

infrastructure.

• Optical VPN (OVPN) is defined as a collection of ports

that connect the CDs owned by the same organization to the service provider network.

• A given service provider network could support

multiple OVPNs.

• A port is actually a collection of channels (e.g.,

lightpath, SDH/SONET circuit).

• Not all ports on a given provider edge optical

network element (PE-ONE) that connect that PE ONE to CDs must belong to the same OVPN.

• One important goal of the mechanism is to support

single ended provisioning.

• It should be possible to reconfigure OVPN (e.g

when CD request to setup a new optical channel trail to another CD within the same VPN) without requiring configuration changes in any of the provider's ONEs.

Reference Model

CD4 CD6 CD5 CD7

VPON B

CD1 CD3 CD2

VPON A

PE1 PE4 PE2 PE3

P P P P

CD1 CD3 CD2 CD4 CD6 CD5 CD7

Mode of Operations

• Within a given OVPN, each port has an identifier

unique only within that OVPN called the Customer Port Identifier (CPI).

• Within a service provider network, each port on a PE

ONE has an identifier that is unique within that service provider network. We refer to this identifier as Provider Port Identifier (PPI).

• Each PE ONE maintains a Port Information Table

(PIT) for each OVPN that has at least one port on that PE ONE. A PIT contains a list of <CPI, PPI> tuples for all the ports within its OVPN.

CPI= <interface index, CD IP address>

Unique number within the CD Unique address within the OVPN

PPI= <interface index, IP address>

Unique number within the PE (per port) Unique address within the SP network

Port Information Table (PIT) <CPI, PPI> . .

Provider Edge ONE (PE)

Backbones GMPLS based

Provider Edge ONE (PE)

BGP information Distribution

OVPN Components

VPN-A PIT VPN B PIT VPN C PIT VPN A PIT VPN B PIT VPN C PIT

A PIT on a given PE ONE is populated from two sources: the

information received from the CDs attached to the ports on that PE ONEs, and the information received from other PE ONEs (received through BGP). BGP BGP

VPN A CD1 VPN B CD1 VPN C CD1 VPN A CD2 VPN B CD2 VPN C CD2

How the mechanism works?

PIT-1 configured with a list of import/export route targets Build <CPI-1, PPI-1> on PIT-1 <CPI-1> <CPI-2>

GMPLS: request <CPI-1,PPI-1>,<CPI-2,PPI-2>

Optical connection

CD1 PE1 PE2 CD2

GMPLS: request connection <CPI-1,CPI-2>

PIT-1 <CPI-2> PIT-2 BGP_MP Information distribution to PEs

GMPLS: request connection <CPI-1,CPI-2>

PIT-2 <CPI-1> Receive information <CPI-2,PPI-2> stored in PIT-1 PIT-2 PIT-2

• A CD need not establish an optical connection to

every target port that CD knows about. Therefore the VPON topology is controlled by the CDs.

• A port, in addition to its CPI and PPI may also

have other information associated with it (e.g., characteristics of the channels within that port like encoding , bandwidth , total unreserved bandwidth within the port, etc).

• The connectivity between CDs is established at the

granularity of channels

Others

• The mechanism applies also to a situation where

the service provider network consists of SONET/SDH cross connects and ports are connected via SONET/SDH sub-channels with each other.

• Since the protocol used to populate a PIT with

remote information is BGP, and since GMPLS signaling isn't restricted to a single routing domain, it follows that this mechanism could support an environment that consists of multiple routing domains.