If the VPN sites are attached to different devices, then you need separate PEs and must be running BGP between them. If all sites attach to the same device, the VRF should be enough to provide the isolation on the same PE. The P router is not mandatory. The memory you require wil also depend on the number of routes in each VRF.
I wouldnt use the NPE-300 to do what you are looking to do. I would opt for the NPE-G1 processor board and even at that depending on how much traffic you have coming out of your box the memory you require could be as much as 1gig.
Introduction: The "external-out enable" command is available for
configuration under the "router ospf process" in case of the IOS-XR
operating system. This command basically enables advertisement of
intra-area routes on the device as external routes in th...
IntroductionIn this article we'll discuss how to troubleshoot packet
loss in the asr9000 and specifically understanding the NP drop counters,
what they mean and what you can do to mitigate them. This document will
be an ongoing effort to improve troublesh...