Cabletron Systems Inc.'s fiscal first-quarter profit dropped sharply as sales of the computer networker's new equipment failed to offset declining sales of older products. Net income before charges for the quarter ended May 31 was $6 million, or 4 cents a diluted share, compared with $58.8 million, or 37 cents, a year earlier. Analysts expected Cabletron to earn 6 cents a share, according to IBES International Inc. Sales were almost flat at $365.7 million. Cabletron's profit has been hurt as Cisco Systems Inc. and other larger rivals have introduced competing products used to link computers to corporate networks and the Internet. Shares of Rochester, N.H.-based Cabletron rose 38 cents to close at $14.31 on the New York Stock Exchange. The results were released after the close of trading.