INTRODUCTION tML Framework Document (ITU-T Recommendation M.3030) identifies potential applications for using XML in the interface design specification. Fault Management (Trouble Administration) is one such application. ITU-T Recommendation M.3020 defines a three phase methodology for developing interface specifications related to management information exchanges. The requirements phase has not been formally defined but is derived from existing ANSI standards T1.227-2000 and T1.228-1995 (R1999). The formal analysis phase from M.3020 is not included in this document. This document presents the design phase using XML schemas (tML TA schemas) for Trouble Administration functions and services specified in T1.227/T1.228. The design phase is a result of analyzing (in the form of UML model) ANSI T1.227/T1.228 data definitions. The model does not include enhanced features such as multiple object operations available based on the protocol design in T1.227/T1.228. A Trouble Administration architecture diagram based on T1.227/T1.228 is shown in Figure 1 below. The approach used in this standard defines XML application protocol data units that are specific to a subset of TA as defined in T1.227/T1.228 (ANSI version of ITU-T X.790). The XML messages specified in this standard are defined via an XML schema (tML-TA schema) and there is no coupling to a transport protocol. While mapping to a transport protocol (such as tML Transport Protocol@ see Ref [15]) is required for interoperability@ it is outside the scope of this document@ and should be addressed by each pair of bonded companies as a joint implementation issue. Purpose The purpose of this document is to provide the XML schemas (tML TA schemas) for trouble administration functions and services specified in T1.227/T1.228.