Exhibit 99.1

   1


                                                                    Exhibit 99.1



                                    AGREEMENT

         Pursuant to Rule 13d-1(f)(1) under the Securities Exchange Act of 1934,
as amended, the undersigned hereby agree that only one statement containing the
information required by Schedule 13G need be filed with respect to the ownership
by each of the undersigned of the shares of Common Stock of Turnstone Systems,
Inc.

         EXECUTED as a sealed instrument this 9th day of February, 2001.



                                         /s/ M. ▇▇▇▇▇▇ ▇▇▇▇▇▇
                                         ------------------------------
                                         M. ▇▇▇▇▇▇ ▇▇▇▇▇▇


                                         /s/ J. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇
                                         ------------------------------
                                         J. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇




                                         The ▇. ▇. ▇▇▇▇▇▇ and M. D. ▇▇▇▇▇▇ Trust
                                         UDT dated January 13, 1995



                                         By: /s/ M. ▇▇▇▇▇▇ ▇▇▇▇▇▇
                                            -----------------------------
                                            M. ▇▇▇▇▇▇ ▇▇▇▇▇▇
                                            Trustee


                                         By: /s/ J. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇
                                            -----------------------------
                                            J. ▇▇▇▇▇▇▇ ▇▇▇▇▇▇
                                            Trustee