Stock Option Exchange Program

BROCADE COMMUNICATIONS SYSTEMS, INC.
STOCK OPTION EXCHANGE PROGRAM
CALCULATOR


This calculator is being provided to assist you in running "what if" scenarios
to determine how the Stock Option Exchange Program would affect you under various user-defined anticipated future market prices of Brocade common stock. This calculator tells you the potential gain you would realize on your existing options and from the options you would receive if you chose to participate in Stock Option Exchange Program assuming all options were fully vested. Brocade is not making any recommendation as to whether you should accept the offer to exchange your options. You must make your own decision as to whether or not to
accept the offer.


This document, the Schedule TO and the Disclosure Documents contain important information about the offer. You should carefully read all of these materials, consult your tax and financial advisors, and understand the risks before making
any decision about whether to participate in the offer.


12/9/02 Tender Offer Date $ 12.00 Price Floor $ 7.00 The exercise price per share at which you expect the new
options to be granted. $ 25.00 Your future expected price per share beyond the grant date at
which you might be interested in exercising and selling
your options.


POTENTIAL POTENTIAL
CELLS REQUIRING INPUT ARE IN YELLOW GAIN GAIN
SHOULD SHOULD
4/17/01 OPTIONS OPTIONS YOU CHOOSE YOU CHOOSE
OPTION OPTION GRANT TYPE OPTIONS TO BE CANCEL:GRANT TO BE NOT TO TO ACCEPT
DATE PRICE (IF APPLICABLE) OUTSTANDING CANCELLED RATIO GRANTED PARTICIPATE THE OFFER --------------------------------------------------------------------------------------------------- ----------- ---------- Option A 11/19/99 $32.13 12,000 12,000 3:1 4,000 $ -- $ 72,000 Option B 11/29/00 $76.88 2,000 2,000 2:1 1,000 $ -- $ 18,000 Option C 4/17/01 $20.70 Supplemental 1,480 1,480 2:1 740 $ 6,364 $ 13,320 Option D 4/17/01 $20.70 Other 1,590 1,590 1:1 1,590 $ 6,837 $ 28,620 Option E 10/1/01 $12.90 -- -- 1:1 -- $ -- $ -- Option F 10/30/01 $24.20 875 875 1:1 875 $ 700 $ 15,750 Option G 10/8/02 $ 5.38 900 900 1:1 900 $ 17,658 $ 16,200 Option H Option I Option J Option K Option L Option M Option N
--------- ------- ----------- ----------
18,845 9,105 $ 31,559 $ 163,890
========= ======= =========== ==========


Instructions:


- Enter the option grant information from your "Personnel Option Status" report in the appropriate cells above.


- You will need to enter the option grant information for each of your separate option grants.


- If you have an option grant dated 4/17/01, select either "Supplemental" or "Other" from the pull-down menu within the appropriate cell above. This calculator will not calculate 4/17/01 option grants unless you select either "Supplemental" or "Other." No selection is required for grants made on any other grant date.


- Your 4/17/01 "Supplemental" options, if applicable, will be highlighted in yellow on your Personnel Option Status report.


Run "what if" scenarios by entering different expected exercise prices per share for your new options and different expected prices per share at which you would be interested in exercising and selling your options.


- You will need to enter your expected future market price of Brocade common stock as of both the grant date and a future date beyond the grant date.


Exhibit 99.(a)(1)(g)
...