6.1. Media Access and Control Protocol

6.1.1. Frame Format

Figure 6.1 shows the format of an Ethernet frame as defined in the original IEEE 802.3 standard. An Ethernet frame starts with a preamble and ends with a Frame Check Sequence (FCS).

Figure 6.1. Ethernet Frame Format

Preamble is a sequence of 56 bits having alternating 1 and 0 values that are used for synchronization. They serve to give components in the network time to detect the presence of a signal, and to begin reading the signal before the frame data arrives. SFD stands for Start Frame Delimiter and is a sequence of 8 bits having the bit configuration 10101011 that indicates the start ...

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