光纤通道使用类似网络osi模型的分层协议。与网络osi模型不同的是，光纤通道协议只有5层：
fc0：物理层，包括线缆，光纤模块等。
fc1：数据链路层，负责8b/10b的信号编码与解码。
fc2：网络层，定义fc-pi-2标准，由核心的光纤通道组成，并且定义了主要的协议。
fc3：公共服务层，瘦层，这一层可以实现数据加密或raid等功能。
fc4：协议映射层，这一层可以封装其他协议，如scsi，封装成信息单元在fc2层上传输。
fc0,1,2被称为物理层。
fibre channel routers operate up to fc4 level (i.e. they may operate as scsi routers), switches up to fc2, and hubs on fc0 only.
fibre channel products are available at 1 gbit/s, 2 gbit/s, 4 gbit/s, 8 gbit/s, 10 gbit/s and 20 gbit/s. products based on the 1, 2, 4 and 8 gbit/s standards should be interoperable, and backward compatible. the 10 gbit/s standard (and 20 gbit/s derivative), however, is not backward compatible with any of the slower speed devices, as it differs considerably on fc1 level (64b/66b encoding instead of 8b/10b encoding). 10gb and 20gb fibre channel is primarily deployed as a high-speed “stacking” interconnect to link multiple switches.
也就是说10g以上都采用64b/66b编码了，所以不再向下兼容8b/10b编码的速率.