KKR 1996 GP LLC

                                      EXHIBIT 1

                                JOINT FILING AGREEMENT

         We, the signatories of the statement on Schedule 13D to which this
Agreement is attached, hereby agree that such statement is, and any amendments
thereto filed by any of us will be, filed on behalf of each of us.

                        KKR 1996 GP LLC 



                        By:/S/ XXXXX XXXXXX 
                           -----------------
                           Name: Xxxxx Xxxxxx 
                           Title:  Member


                        KKR ASSOCIATES 1996 L.P.

                             By KKR 1996 GP LLC, as
                             General Partner


                             By:/S/ XXXXX XXXXXX 
                                -----------------
                                Name: Xxxxx Xxxxxx  
                                Title:  Member


                        KKR 1996 FUND L.P.

                           By KKR ASSOCIATES 1996 L.P., as
                             General Partner

                             By KKR 1996 GP LLC, as
                             General Partner


                             By:/S/ XXXXX XXXXXX 

                                -----------------
                                Name: Xxxxx Xxxxxx  
                                Title:  Member


                                                                               2

                        NXS I, L.L.C.

                         By KKR 1996 FUND L.P., as
                            Member

                           By KKR ASSOCIATES 1996 L.P., as
                             General Partner

                             By KKR 1996 GP LLC, as
                             General Partner


                             By:/S/ XXXXX XXXXXX 
                                -----------------
                                Name: Xxxxx Xxxxxx  
                                Title:  Member   


DATED:  January 31, 1997