Exhibit 15.1

Kost Forer Gabbay & Kasierer   3 Aminadav St. Tel-Aviv 67067, Israel   Tel:  972 (3)6232525 Fax: 972 (3)5622555 www.ey.com

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consaent to the incorporation by reference in this Registration Statement on Form S-8 (File Nos. 333-140701, 333-149237, 333-159306, 333-165144, 333-172492, 333180770, 333-187406, 333-194833, 333-203028 and 333-210420) pertaining to the 2016 Incentive Compensation Plan of Allot Communications Ltd., of our report dated March 23, 2017, with respect to the consolidated financial statements and the effectiveness of internal control over financial reporting of Allot Communication Ltd. included in this annual report on Form 20-F for the year ended December 31, 2016.

/s/ KOST FORER GABBAY & KASIERER

KOST FORER GABBAY & KASIERER

A Member of Ernst & Young Global

Tel Aviv, Israel

March 23, 2017