TheStreet.com Ratings provides exclusive stock, ETF and mutual fund ratings and commentary based on award-winning, proprietary tools. Its "safety first" approach to investing aims to reduce risk while seeking total return performance.BOSTON ( TheStreet) -- TheStreet.com's stock-picking model upgraded networking-equipment giant Cisco ( CSCO) to "buy." The numbers: Fiscal third-quarter revenue decreased 17% to $8.2 billion as net income fell 24% to $1.3 billion and earnings per share fell 21% to 23 cents, helped by a lower share count. The operating margin expanded from 20% to 22%, but the net margin dropped from 18% to 17%. Cisco's debt load has increased 49% from the year-ago quarter, but a debt-to-equity ratio of 0.3 demonstrates a conservative capital structure. And a quick ratio of 2.9 indicates strong liquidity. The stock: Cisco is up 33% this year, beating major U.S. indices. The stock trades at a price-to-earnings ratio of 18, a modest premium on the market, and doesn't pay dividends. The company will benefit from a rebound in tech spending as the global economy recovers. The model upgraded media company Discovery Communications ( DISCA) to "hold." The company runs television networks including the Discovery Channel, TLC and Animal Planet. The numbers: First-quarter revenue inched up 1% to $817 million as net income tripled to $119 million. However, earnings per share climbed just 17% due to a significantly higher share count. The operating margin strengthened from 30% to 33% and the net margin improved from 4% to 15%. The company has added $3.7 billion of debt since the year-ago quarter, when the balance stood at zero. But a debt-to-equity ratio of 0.8 indicates reasonable leverage. With only $142 million of cash and a quick ratio of 0.8, Discovery's liquidity position is less than ideal.