1 RI present. The Information field may be LLC, MAC or SMT protocol. FCS Frame check sequence. LLC type I service provides a datalink connectionless mode service, while LLC type II provides a connection-oriented service at the datalink layer. The LLC header structure is shown in the illustration below.
Transmitter send sequence number.
Transmitter receive sequence number. X Reserved and set to zero. M Modifier function bits. LLC information LLC data or higher layer protocols. ATM cells can be carried over many different physical media, from optical fiber to spread spectrum radio.