Transmitting Bits on the Media
A stream of Transmission Words on a link may be further transformed to provide Forward Error Correction (FEC). When FEC is enabled, a sender adds a few parity (redundant) bits before data transmission. The parity bits allow a receiver to detect a limited number of errors and may correct these errors without re-transmission. 链路上的传输字流经进一步转换后，可提供前向纠错功能（FEC）。启用 FEC 后，发送方会在数据传输前添加一些奇偶校验（冗余）位。这些奇偶校验位允许接收器检测到数量有限的错误，并在不重新传输的情况下纠正这些错误。
Finally, the bits are transmitted to the media. 最后，这些比特被传输到媒体上。
To summarize, bits are grouped into words that are encoded into Transmission Words. Transmission Words have parity words to support FEC. The Transmission Words can carry data or convey a special function in the form of an Ordered Set. Data from upper-layer protocols are carried in the Data Field of Fibre Channel frames which are encoded in Data Transmission Words whereas ordered sets such as SOF, EOF, Idle, and R_RDY are encoded in Control Transmission Words. 概括地说，比特被分组为字，字被编码为传输字。传输字具有奇偶校验字，以支持 FEC。传输字可携带数据或以有序集的形式传递特殊功能。上层协议的数据在光纤通道帧的数据字段中传输，数据字段在数据传输字中编码，而 SOF、EOF、Idle 和 R_RDY 等有序集在控制传输字中编码。
Next, let’s understand the Fibre Channel baud rate, bit rate, and data rate as shown in Table 2-4. 接下来，让我们了解一下光纤通道波特率、比特率和数据率，如表 2-4 所示。
Table 2-4 Fibre channel speeds, baud rate, bit rate, and data rate
Fibre Channel Baud Rate
The baud rate is the number of symbols transmitted per second. For example, a