美墨電信爭端案為WTO首件處理服務貿易之案件，亦是爭端解決小組首次審理電信服務貿易相關規範。本案小組提出關於GATS、電信參考文件與電信附件之重要解釋，並揭示會員應確保國際互連費率之成本導向原則。跨國電信服務網路互連費率問題，確實為電信服務貿易之最主要爭議之一。「1997年WTO電信攤分費率最惠國待遇豁免瞭解書」的效力問題，更使「國際話務攤分費率」爭議複雜化。本案小組強調，該瞭解書之目的是為了避免會員為遵循ITU做法而紛紛提出最惠國待遇豁免。因此，國際互連問題並不必然落於電信參考文件之適用範圍外。 然而，在「國際單純語音轉售服務」（ISR）議題上，小組做出有利於墨國之裁決。美國業者仍被禁止以＜模式一＞方式，跨境提供國際單純語音轉售服務。由於ISR可以被理解為「以＜模式一＞跨境提供電信服務的另一種型態」，此問題其實與國際網路互連費率爭議密切相關，對於未來電信服務貿易市場，亦有關鍵影響。 本文第一部份介紹本爭端案重要法律問題。第二部分則分析小組報告中對於GATS相關條文與附則之解釋，並嘗試以批判角度評析小組見解。此外，本部分亦論及我國法制之WTO適法性。本文最後部分著重於本案對於未來WTO電信服務貿易規範之影響。此分析以跨境提供電信服務的市場利益結構為核心，兼論新興科技對於現行WTO電信服務貿易規範之衝擊，並強調DSB對於電信參考文件未來規範演化之重要性。

The Mexico-U.S. Telecom Dispute is the first panel proceeding in the WTO to deal solely with trade in services under the GATS. The case is also the first WTO panel proceeding to deal with telecom services. The Panel delivered a broad interpretation of the GATS, Reference Paper and the Annex on Telecommunications, by ruling that Members must provide cost-oriented interconnections for all international phone calls terminating in their market. Indeed, one of the most contentious issues in the negotiations on basic telecom services in 1997 was the treatment of "accounting rates' for switched international services. The legal status of the so-called "1997 Understanding" further complicated the issues. The Panel concluded that the accounting rates described in the Understanding should be narrowly interpreted. However, the Panel had sided with Mexico on the ISR issue by ruling that Mexico had made no commitments in the WTO to allow such practices. ISR, which is exempt from the settlement rate, permits a foreign carrier to lease a transmission circuit between countries and then send switched voice and data traffic over the circuit. ISR is better understood as the logical alternative of being able to create a cross-border transport network under the control of a single carrier. This finding, therefore, is significant to the future Mexico-U.S. telecom services. The first part of this paper briefly explains the major issues of the Mexico-U.S. Telecom Dispute. The second part further analyzes the legal arguments at the heart of the controversy. The third part examines the significance of the accounting rate debate, and explains why it is so politically and economically difficult to get good policy and practice on these issues. The final part highlights some possible changes in the market for traditional international switched services. The last WTO round focused on the world of traditional switched services, predominantly over the wired network. One critique formulated against the Reference Paper is that many of its provisions are vague and that key concepts are no defined. However, the recent Telecom Dispute proved that the Reference Paper is a valuable document that provides a set of safeguards against anticompetitive practices that could limit market access. In addition, the DSB plays a critical role while members maintain a sufficient degree of flexibility in the PR.