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VPWS question

peter.thomsen
Level 1
Level 1

Hi there.

We are starting our MPLS implementation. We have bridged traffic where we need L2 VPN implementation. PWE3 is NOT a solution for us so we were thinking of using VPLS whic is great. Only problem is our MPLS infrastructure isbased on GSR12K (P=12406 and PE=12410). GSR12K will not support VPLS until 33S, which is earliest mid 2005. Is there any one out there who has expierience with VPWS?? If so, is it complexed?? It is p2p just like PWE3 so what is the difference??

Thanks

Peter.

4 Replies 4

peter.thomsen
Level 1
Level 1

Hi all.

Just digging a bit more. Is VPWS the same as PWE3??

Peter.

VPWS

The PE devices provide a logical interconnect such that a pair of CE

devices appear to be connected by a single logical Layer-2 circuit.

PE devices act as Layer-2 circuit switches. Layer-2 circuits are

then mapped onto tunnels in the SP network. These tunnels can

either be specific to a particular VPWS, or shared among several

services. VPWS applies for all services including Ethernet, ATM,

Frame Relay etc.

Each PE device is responsible for allocating customer Layer-2 frames

to the appropriate VPWS and for proper forwarding to the intended

destinations.

8.2.1 Encapsulation

A L2VPN solution SHOULD utilize the encapsulation techniques defined

by PWE3 ([PWE3_ARCH]), and SHOULD not impose any new requirements on

these techniques.

+-----+ +-----+

+ CE1 +--+ +---| CE2 |

+-----+ | ........................ | +-----+

L2VPN A | +----+ +----+ | L2VPN A

+--| PE |--- Service ---| PE |--+

+----+ Provider +----+

/ . Backbone . \ - /\-_

+-----+ / . | . \ / \ / \ +-----+

+ CE4 +--+ . | . +--\ Access \----| CE5 |

+-----+ . +----+ . | Network | +-----+

L2VPN B .........| PE |......... \ / L2VPN B

+----+ ^ -------

PWE3

A pseudo-wire (PW) is a connection between two provider edge (PE)

devices which connects two attachment circuits (ACs). An AC can be a

Frame Relay DLCI, an ATM VPI/VCI, an Ethernet port, a VLAN, a HDLC

link, a PPP connection on a physical interface, a PPP session from an

L2TP tunnel, an MPLS LSP, etc.

|<------- Pseudo Wire ------>|

| |

| |<-- PSN Tunnel -->| |

V V V V

+----+ +----+

+-----+ | PE1|==================| PE2| +-----+

| |----------|............PW1.............|----------| |

| CE1 | | | | | | CE2 |

| |----------|............PW2.............|----------| |

+-----+ ^ | |==================| | +-----+

^ | +----+ +----+ ^

| | Provider Edge 1 Provider Edge 2 |

| | |

| Attachment Circuit |

| |

|<-------------- Emulated Service ---------------->|

Customer Customer

Edge 1 Edge 2

Figure 1: PWE3 Reference Model

During the setup of a PW, the two PEs will be configured or will

automatically exchange information about the service to be emulated

so that later they know how to process packets coming from the other

end. After a PW is set up between two PEs, frames received by one PE

from an AC are encapsulated and sent over the PW to the remote PE,

where native frames are re-constructed and forwarded to the other CE.

Thanks a lot.

Peter.