link in a controlled way. Not saying that's a particularly good use, just that that's the most common reason I've seen it deployed on otherwise simple point-to-points. The idea behind frame relay is that it gives you a multipoint layer-2 protocol to use on a more complicated network of circuits.
-Bill
It can also be used to 'equalize' two links of different speeds in such a way that you can do reasonable equal-cost load-balancing. For example, if you have a DS3 and an OC3, you can create 3 FR subinterfaces on the OC3 and add the DS3 to the mix to give you essentially 4 DS3s. There is a slight speed difference, but it is minimal. This can be done for 2 OC-12s and an OC-48, for example. Another reason for virtualizing a ptp circuit is for differentiate billing in a MPLS VPN environment with an Internet offload component. You can direct VPN traffic on one VC and Internet on the other, and then take advantage of basic MIB-II stats for billing and per-(sub)interface CAR for enforcement of contract and reclassification, etc. regards, chris