AT&T put in a 150 Mbps fiber line at our business (not my home). They claim it uses the PPP protocol (I am told this is non-Ethernet), but is terminated in multi-mode fiber using 1000BASE SX (an Ethernet standard). Note that their documents (the OSM, Order Status Management site) say it is PPP, not PPPoE.

My questions are:

• is PPP (not PPPoE) actually incompatible with Ethernet?
• will a Cisco router with an SFP in a Gig-e port be able to handle this, or else what is an example of a "wic" that can handle PPP over fiber? (Googling has not helped so far.)