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.