This week, the overall grades of five communications equipment stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, ARRIS Group, Inc. (ARRS) falls to a D (“sell”), worse than last week’s grade of C (“hold”). ARRIS is a global communications technology company specializing in the design and engineering of broadband network solutions. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. To get an in-depth look at ARRS, get Portfolio Grader’s complete analysis of ARRS stock.

Applied Optoelectronics, Inc. (AAOI) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a C (“sell”). The stock gets F’s in Earnings Surprise and Cash Flow. As of March 12, 2015, 11.4% of outstanding Applied Optoelectronics, Inc. shares were held short. The stock has a trailing PE Ratio of 46.50. For more information, get Portfolio Grader’s complete analysis of AAOI stock.

Slipping from a C to a D rating, Dragonwave Inc. (DRWI) takes a hit this week. DragonWave is a producer of high-capacity packet microwave solutions which support networking and other data transmission needs. The stock gets F’s in Equity and Cash Flow. To get an in-depth look at DRWI, get Portfolio Grader’s complete analysis of DRWI stock.

Clearfield, Inc. (CLFD) experiences a ratings drop this week, going from last week’s D to an F. Clearfield offers telecommunications equipment and products in the United States. The stock gets F’s in Earnings Growth, Earnings Momentum and Sales Growth. The trailing PE Ratio for the stock is 40.90. For more information, get Portfolio Grader’s complete analysis of CLFD stock.

Sonus Networks, Inc.’s (SONS) rating weakens this week, dropping to a D versus last week’s C. Sonus Networks provides voice infrastructure solutions for wireline and wireless service providers. To get an in-depth look at SONS, get Portfolio Grader’s complete analysis of SONS stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.