The ratings of eight Communications Equipment stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

F5 Networks‘s (NASDAQ:FFIV) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. F5 Networks provides integrated Internet traffic management solutions designed to improve the availability and performance of mission-critical Internet-based servers and applications. The stock has a trailing PE Ratio of 28.80. For a full analysis of FFIV stock, visit Portfolio Grader.

Juniper Networks (NYSE:JNPR) ratings are on the decline this week as the company earns a F (“strong sell”). Last week, it received a D (“sell”). Juniper Networks provides Internet infrastructure solutions for Internet service providers and other telecommunications service providers. The stock price has fallen 10.2% over the past month, worse than the S&P 500, which has remained flat over the same period of time. The stock’s trailing PE Ratio is 33.80. To get an in-depth look at JNPR, get Portfolio Grader’s complete analysis of JNPR stock.

This week, Plantronics (NYSE:PLT) drops from a C to a D rating. Plantronics designs, manufactures, and markets lightweight communications headsets and headset accessories and services. Wall Street appears to agree with the stock downgrade, with share prices dropping 5% over the past month. For more information, get Portfolio Grader’s complete analysis of PLT stock.

Comtech Telecommunications (NASDAQ:CMTL) earns a F this week, moving down from last week’s grade of D. Comtech Telecommunications is involved in the design, development, production, and marketing of products, systems, and services for advanced communications solutions. The stock also gets an F in Sales Growth. The stock price has fallen 7.2% over the past month. For a full analysis of CMTL stock, visit Portfolio Grader.

Arris Group‘s (NASDAQ:ARRS) rating weakens this week, dropping to a D versus last week’s C. ARRIS Group is a global communications technology company specializing in the design and engineering of broadband network solutions. The stock also gets an F in Margin Growth. Share prices fell 9% over the past month. To get an in-depth look at ARRS, get Portfolio Grader’s complete analysis of ARRS stock.

This is a rough week for Digi International (NASDAQ:DGII). The company’s rating falls to F from the previous week’s D. Digi International develops products and technologies to connect and manage local or remote electronic devices over a network, via the Internet or via satellite. The stock also rates an F in Sales Growth. Investors seem to agree with the downgrade and have pushed down the share price 11% over the past month. The stock currently has a trailing PE Ratio of 31.80. For more information, get Portfolio Grader’s complete analysis of DGII stock.

Tellabs (NASDAQ:TLAB) gets weaker ratings this week as last week’s D drops to a F. Tellabs sells networking equipment that telecom service providers use to manage voice and data traffic on their networks. The stock gets F’s in Equity, Cash Flow, and Sales Growth. Share prices fell 6.6% over the past month. To get an in-depth look at TLAB, get Portfolio Grader’s complete analysis of TLAB stock.

This week, AudioCodes‘ (NASDAQ:AUDC) rating worsens to a F from the company’s D rating a week ago. AudioCodes designs, develops, and markets products for voice and data over packet networks. The stock gets F’s in Earnings Growth, Earnings Revisions, and Equity. Margin Growth and Sales Growth also get F’s. For a full analysis of AUDC stock, visit Portfolio Grader.

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.