Director/PDMR Shareholding

Spirent Communications PLC
08 September 2006

                                SPIRENT COMMUNICATIONS PLC

                                     (the "Company")


                           NOTIFICATION OF DEEMED INTERESTS

                     BY DIRECTORS, PERSONS DISCHARGING MANAGERIAL

                          RESPONSIBILITY OR CONNECTED PERSONS



The Company was notified on 7 September 2006 that Spirent Sharesave Trust
Limited, the trustee for the Spirent Sharesave Trust (the "Trust") had
transferred Ordinary shares to satisfy the exercise of options under the
Company's Savings Related Share Option Scheme as follows:



No of Shares                       Option Price

10,866                               38 pence



Following this transfer the total number of Ordinary shares held by the Trust
is:



2,154,313  (representing 0.2351% of the issued share capital of the Company).



The Company's executive directors are potential beneficiaries of the Trust
(together with all other UK employee share option holders) and are, therefore,
treated under the Companies Act 1985 as having a deemed interest in the total
number of shares held by the Trust.  As a result, the directors' deemed interest
in the Trust has been reduced by the above number of shares transferred.



For the avoidance of doubt, the Company confirms that this notification does not
relate to an actual dealing in securities by the executive directors whose
interests in the Company's securities remain unchanged notwithstanding the above
events.





Warren Nash
Spirent Communications plc


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