On CALX's earnings call last night, management expressed keen interest in improving its international footprint.
ZHNE would provide CALX with a business that derives over 60% of revenue from outside of the U.S. (despite a substantial commitment to U.S.-based manufacturing).
CALX already acquired one Stimulus-related competitor (OCNW). Taking out ZHNE would provide the international exposure it seeks along with a company whose expenses could be substantially improved to the benefit of its acquirer.
Considering the nascent recovery in Stimulus spending, the timing for a deal could be right.
Disclosure: I am long CALX, ZHNE.