Redback Networks

(RBAK)

was down 8.3% in early trading after hitting a 52-week low of $17.08.

U.S. Bancorp Piper Jaffray

downgraded the stock to buy from strong buy and slashed its price target to $28 from $68.

Other network-equipment makers were also falling in the wake of Friday's layoffs announcement from

Cisco

(CSCO) - Get Report

.

Sycamore

(SCMR)

was down 8% after hitting 52-week low of $12.63.