Contingencies	3 Months Ended
Apr. 30, 2011
Contingencies [Abstract]
CONTINGENCIES	(19) CONTINGENCIES Foreign Tax Contingencies Ciena has received assessment notices from the Mexican tax authorities asserting deficiencies in payments between 2001 and 2005 related primarily to income taxes and import taxes and duties. Ciena has filed judicial petitions appealing these assessments. As of October 31, 2010 and April 30, 2011, Ciena had accrued liabilities of $1.4 million and $1.6 million, respectively, related to these contingencies, which are reported as a component of other current accrued liabilities. As of April 30, 2011, Ciena estimates that it could be exposed to possible losses of up to $5.8 million, for which it has not accrued liabilities. Ciena has not accrued the additional income tax liabilities because it does not believe that such losses are more likely than not to be incurred. Ciena has not accrued the additional import taxes and duties because it does not believe the incurrence of such losses are probable. Ciena continues to evaluate the likelihood of probable and reasonably possible losses, if any, related to these assessments. As a result, future increases or decreases to accrued liabilities may be necessary and will be recorded in the period when such amounts are estimable and more likely than not (for income taxes) or probable (for non-income taxes). In addition to the matters described above, Ciena is subject to various tax liabilities arising in the ordinary course of business. Ciena does not expect that the ultimate settlement of these liabilities will have a material effect on our results of operations, financial position or cash flows. Litigation On May 29, 2008, Graywire, LLC filed a complaint in the United States District Court for the Northern District of Georgia against Ciena and four other defendants, alleging, among other things, that certain of the parties’ products infringe U.S. Patent 6,542,673 (the “’673 Patent”), relating to an identifier system and components for optical assemblies. The complaint, which seeks injunctive relief and damages, was served upon Ciena on January 20, 2009. Ciena filed an answer to the complaint and counterclaims against Graywire on March 26, 2009, and an amended answer and counterclaims on April 17, 2009. On April 27, 2009, Ciena and certain other defendants filed an application for inter partes reexamination of the ‘673 Patent with the U.S. Patent and Trademark Office (the “PTO”). On the same date, Ciena and the other defendants filed a motion to stay the case pending reexamination of all of the patents-in-suit. On July 17, 2009, the district court granted the defendants’ motion to stay the case. On July 23, 2009, the PTO granted the defendants’ application for reexamination with respect to certain claims of the ‘673 Patent. On March 17, 2011, the PTO granted a third party application for reexamination with respect to one claim of the ‘673 Patent. Ciena believes that it has valid defenses to the lawsuit and intends to defend it vigorously in the event the stay of the case is lifted. As a result of its June 2002 merger with ONI Systems Corp., Ciena became a defendant in a securities class action lawsuit filed in the United States District Court for the Southern District of New York in August 2001. The complaint named ONI, certain former ONI officers, and certain underwriters of ONI’s initial public offering (IPO) as defendants, and alleges, among other things, that the underwriter defendants violated the securities laws by failing to disclose alleged compensation arrangements in ONI’s registration statement and by engaging in manipulative practices to artificially inflate ONI’s stock price after the IPO. The complaint also alleges that ONI and the named former officers violated the securities laws by failing to disclose the underwriters’ alleged compensation arrangements and manipulative practices. The former ONI officers have been dismissed from the action without prejudice. Similar complaints have been filed against more than 300 other issuers that have had initial public offerings since 1998, and all of these actions have been included in a single coordinated proceeding. On October 6, 2009, the Court entered an opinion granting final approval to a settlement among the plaintiffs, issuer defendants and underwriter defendants, and directing that the Clerk of the Court close these actions. Notices of appeal of the opinion granting final approval have been filed, all of which have been either resolved or dismissed, except one. A description of this litigation and the history of the proceedings can be found in “Item 3. Legal Proceedings” of Part I of Ciena’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on December 22, 2010. No specific amount of damages has been claimed in this action. Due to the inherent uncertainties of litigation and because the settlement remains subject to appeal, the ultimate outcome of the matter is uncertain. In addition to the matters described above, Ciena is subject to various legal proceedings, claims and litigation arising in the ordinary course of business. Ciena does not expect that the ultimate costs to resolve these matters will have a material effect on its results of operations, financial position or cash flows.

(19) CONTINGENCIES

Foreign Tax Contingencies

Ciena has received assessment notices from the Mexican tax authorities asserting deficiencies in payments between 2001 and 2005 related primarily to income taxes and import taxes and duties. Ciena has filed judicial petitions appealing these assessments. As of October 31, 2010 and April 30, 2011, Ciena had accrued liabilities of $1.4 million and $1.6 million, respectively, related to these contingencies, which are reported as a component of other current accrued liabilities. As of April 30, 2011, Ciena estimates that it could be exposed to possible losses of up to $5.8 million, for which it has not accrued liabilities. Ciena has not accrued the additional income tax liabilities because it does not believe that such losses are more likely than not to be incurred. Ciena has not accrued the additional import taxes and duties because it does not believe the incurrence of such losses are probable. Ciena continues to evaluate the likelihood of probable and reasonably possible losses, if any, related to these assessments. As a result, future increases or decreases to accrued liabilities may be necessary and will be recorded in the period when such amounts are estimable and more likely than not (for income taxes) or probable (for non-income taxes).

In addition to the matters described above, Ciena is subject to various tax liabilities arising in the ordinary course of business. Ciena does not expect that the ultimate settlement of these liabilities will have a material effect on our results of operations, financial position or cash flows.

Litigation

On May 29, 2008, Graywire, LLC filed a complaint in the United States District Court for the Northern District of Georgia against Ciena and four other defendants, alleging, among other things, that certain of the parties’ products infringe U.S. Patent 6,542,673 (the “’673 Patent”), relating to an identifier system and components for optical assemblies. The complaint, which seeks injunctive relief and damages, was served upon Ciena on January 20, 2009. Ciena filed an answer to the complaint and counterclaims against Graywire on March 26, 2009, and an amended answer and counterclaims on April 17, 2009. On April 27, 2009, Ciena and certain other defendants filed an application for inter partes reexamination of the ‘673 Patent with the U.S. Patent and Trademark Office (the “PTO”). On the same date, Ciena and the other defendants filed a motion to stay the case pending reexamination of all of the patents-in-suit. On July 17, 2009, the district court granted the defendants’ motion to stay the case. On July 23, 2009, the PTO granted the defendants’ application for reexamination with respect to certain claims of the ‘673 Patent. On March 17, 2011, the PTO granted a third party application for reexamination with respect to one claim of the ‘673 Patent. Ciena believes that it has valid defenses to the lawsuit and intends to defend it vigorously in the event the stay of the case is lifted.

As a result of its June 2002 merger with ONI Systems Corp., Ciena became a defendant in a securities class action lawsuit filed in the United States District Court for the Southern District of New York in August 2001. The complaint named ONI, certain former ONI officers, and certain underwriters of ONI’s initial public offering (IPO) as defendants, and alleges, among other things, that the underwriter defendants violated the securities laws by failing to disclose alleged compensation arrangements in ONI’s registration statement and by engaging in manipulative practices to artificially inflate ONI’s stock price after the IPO. The complaint also alleges that ONI and the named former officers violated the securities laws by failing to disclose the underwriters’ alleged compensation arrangements and manipulative practices. The former ONI officers have been dismissed from the action without prejudice. Similar complaints have been filed against more than 300 other issuers that have had initial public offerings since 1998, and all of these actions have been included in a single coordinated proceeding. On October 6, 2009, the Court entered an opinion granting final approval to a settlement among the plaintiffs, issuer defendants and underwriter defendants, and directing that the Clerk of the Court close these actions. Notices of appeal of the opinion granting final approval have been filed, all of which have been either resolved or dismissed, except one. A description of this litigation and the history of the proceedings can be found in “Item 3. Legal Proceedings” of Part I of Ciena’s Annual Report on Form 10-K filed with the Securities and Exchange Commission on December 22, 2010. No specific amount of damages has been claimed in this action. Due to the inherent uncertainties of litigation and because the settlement remains subject to appeal, the ultimate outcome of the matter is uncertain.