Cabletron Systems Inc has bought a minority stake in small networking equipment maker Yago Systems Inc, which is one of the companies readying products in the switching router category. Yago plans to demonstrate its MSR 8000 switching router technology at a show next month. Cabletron’s stake, which hasn’t been disclosed, gives the company a interest in the switching router technology which breaks away form its reliance on just switches. Yago has 40 employees. The company’s co-founder, president and chief executive Robert Levine stepped down last month to be replaced by Don Reed, a former senior officer at local telecoms carrier, Nynex Corp.