What are the phisical limitation on sup32 platform without OSM modules because VPLS is cann't run?
sup32 can do l2tunnels and allow to configure vfi in Version 12.2(33)SRA2, what are the OSM modules hardware provide that are such needed for VPLS?
Neither Sup32 nor Sup720 are capabale to provide VPLS, but SIP400 or OSM modules have an additional processor onboard to provide VPLS features (concurrent MPLS and Ethernet).
As you don't have a SIP400 or OSM, it should be not possible to configure a VFI. Ok, you can configure it, might be a failure, but it will not come up until you add a SIP400/OSM to your system. It is mandatory.