Our sources at Cisco Systems have been telling us that the router maker is pretty interested in peer-to-peer networking technologies, especially as video on the Internet starts to explode.

The company made its intentions known today by investing in Oversi, an Israeli P2P traffic management start-up that is developing P2P based video servers. The $2 million investment takes Oversi’s second round funding to a total of $8 million. Existing venture investors StageOne and TempoPark Fund also participated in this latest $2 million infusion.

While it is not the only game in town — Cachelogic and PeerApp come to mind — it is the only start-up to get the backing of a company whose routers and switches are key ingredients of most networks.