The ratings of 4 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”).

Ciena Corporation (CIEN) experiences a ratings drop this week, going from last week’s C to a D. Ciena Corporation provides communications networking equipment, software, and services that support the transport, switching, aggregation, and management of voice, video, and data traffic. For more information, get Portfolio Grader’s complete analysis of CIEN stock.

ShoreTel, Inc. (SHOR) earns a F this week, moving down from last week’s grade of D. ShoreTel, Inc. is a provider of Internet Protocol, or IP, unified communications systems for enterprises. The company also gets F’s in earnings growth and earnings revisions. For more information, get Portfolio Grader’s complete analysis of SHOR stock.

Slipping from a C to a D rating, Sonus Networks, Inc. (SONS) takes a hit this week. Sonus Networks, Inc. provides voice infrastructure solutions for wireline and wireless service providers. The company also gets F’s in earnings revisions. For more information, get Portfolio Grader’s complete analysis of SONS stock.

PCTEL, Inc.’s (PCTI) rating weakens this week, dropping to a D versus last week’s C. PCTEL, Inc. develops and supplies software-based connectivity solutions. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings revisions, earnings momentum, and free cash flow. For more information, get Portfolio Grader’s complete analysis of PCTI 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.