SAN over SONET service allows carriers to leverage and reuse their extensive SONET infrastructure as opposed to building new overlay networks. SAN over SONET enables carriers to limit capital and operational expenses while capturing significant revenue through: 1) mid-tier enterprise market for data storage; 2) more efficient and expanded SAN offerings. SAN over SONET services can be managed like any other TDM services. Sub-rate to full-rate SAN distance extensions are one important option. While the decision on what of types and range of services can be offered is well understood there are choices as to the “best” implementation for SAN over SONET mapping. GFP-T, GFP-F, and Codeword GFP are being proposed to the standards bodies and being actively discussed. In this paper we will discuss what aspect of transport and storage protocols are important for large carriers to consider when advocating a particular approach in standards bodies.