Cabletron Systems Inc is once again the subject of speculation about its future. According to a report that will appear in the next issue of Business Week, Alcatel SA, Nortel Networks Corp, and Siemens AG are all considering the possibility of acquiring the struggling company. It the assets were broken up, the company would be worth at least $20 per share, according to SG Cowen Securities Corp analyst Chris Stix, quoted in the article. Shares in Cabletron have risen 56% since the start of the year on the strength of such speculation.