MPLS P/PE

[georges_nassif]

Hi,

I just need to know if a P router can be at the same time PE router and what about performance?

Thanks in advance

[jcozzupoli]

Hello Georges,

Well I think what you are asking is that is it possible for a router to act both as a P and a PE router at the same time. To explain some fundamental differences first:

• P routers don't participate in BGP routing in the MPLS Core, and only participates in the IGP routing in order to pass MPLS Labels through the core between the various PE routers.
• PE routers, are the termination points for customer CE routers and therefore, need to participate in BGP (MP-BGP more like it) in order to pass routers from 1 customer CE router to another, where ever the destination may be.

To answer your question, a router can act as both a P and PE router if your network only consists of 4 or 5 routers. But as this is usually not the case, this is not the optimum as you may have hundreds of customers so for this reason you are best to have seperate P routers inside the core and have a number PE routers based on your customer base as it grows.

HTH.

Thanks,

Joe.

[georges_nassif]

Thanks Joe for your answer,

In deed i needed to know if a router can act as P and PE at the same time, it's for a small network and not fro a service provider.

Thanks

[Nagendra Kumar Nainar]

Hi,

PE router is the one where CE connections will be termin
ated and this router will be aware of all CE routes.

P router is the one which connects all PE and will not have any CE routes installed. As you might be aware, it uses the topomost label to reach the outgoing PE from where the packets will be forwarded to CE.

With above, any MPLS router can be either P or PE. There is no way of having a router as P/PE.

If your question is to simulate a simple MPLS topology, it can done by connecting 2 PEs back to back.

HTH,

Nagendra