This announcement is neither an offer to purchase nor a solicitation of an offer to sell Shares. The Offer (as
defined below) is made solely by the Offer to Purchase, dated October 27, 1999, and the related Letter of
Transmittal, and any amendments or supplements thereto, and is being made to all holders of Shares. The Offer is
not being made to (nor will tenders be accepted from or on behalf of) holders of Shares residing in any
jurisdiction in which the making of the Offer or the acceptance thereof would not be in compliance with the laws
of such jurisdiction. However, Purchaser (as defined below) may in its discretion take such actions as it may
deem necessary to make the Offer in any jurisdiction and extend the Offer to holders of Shares in such
jurisdiction. In any jurisdiction where securities, blue sky or other laws require the Offer to be made by a licensed
broker or dealer, the Offer shall be deemed to be made on behalf of Purchaser by Credit Suisse First Boston
Corporation ("Credit Suisse First Boston" or the "Dealer Manager") or one or more registered brokers or dealers
licensed under the laws of such jurisdictions.
NOTICE OF OFFER TO PURCHASE FOR CASH
ALL OF THE OUTSTANDING SHARES OF COMMON STOCK
PREMISYS COMMUNICATIONS, INC.
$10.00 NET PER SHARE
ZHONE ACQUISITION CORP.
A WHOLLY OWNED SUBSIDIARY
ZHONE TECHNOLOGIES, INC.
Zhone Acquisition Corp., a Texas corporation ("Purchaser") and a wholly owned subsidiary of Zhone
Technologies, Inc., a Delaware corporation ("Parent"), is offering to purchase all of the outstanding common
shares, including the associated preferred stock purchase rights (the "Shares") of Premisys Communications, Inc.,
a Delaware corporation (the "Company") at $10.00 per Share, net to the seller in cash, without interest thereon,
on the terms and subject to the conditions set forth in the Offer to Purchase dated October 27, 1999 (the "Offer
to Purchase") and in the related Letter of Transmittal (which together, as eith