EXHIBIT A AGREEMENT OF REPORTING PERSONS Each of the undersigned hereby agrees that Amendment No. 1 to the Schedule 13G filed on the date hereof with respect to the shares of Common Stock of Pivotal Corporation has been filed on behalf of the...

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                                    EXHIBIT A

AGREEMENT OF REPORTING PERSONS

     Each of the undersigned hereby agrees that Amendment No. 1 to the Schedule
13G filed on the date hereof with respect to the shares of Common Stock of
Pivotal Corporation has been filed on behalf of the undersigned.

SIGNATURE:

     Dated: February 14, 2001

     Entities:

Oak Investment Partners VI, Limited Partnership
Oak Associates VI, LLC
Oak VI Affiliates Fund, Limited Partnership
Oak VI Affiliates, LLC
Oak Management Corporation


                                   By:      /s/ Xxxxxx X. Xxxxxxxxxx
                                            ------------------------
                                            Xxxxxx X. Xxxxxxxxxx, as
                                            General Partner or
                                            Managing Member or as
                                            Attorney-in-fact for the
                                            above-listed entities
     Individuals:

Bandel X. Xxxxxx
Xxxxxx X. Xxxxxxxxx
Xxxxxx X. Xxxxxxxxxx
Xxxxxxx X. Xxxxxx
Xxx X. Xxxxxx


                                   By:      /s/ Xxxxxx X. Xxxxxxxxxx
                                            ------------------------
                                            Xxxxxx X. Xxxxxxxxxx,
                                            Individually and as
                                            Attorney-in-fact for the
                                            above-listed individuals