Introduction to Data Communications
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It is used for transferring information or data between Source and Destination in a Type 2 (connection oriented) operation. It is the only LLC PDU allowed to transfer information in Type 2 operation.

The last bit is set to 0, to indicate that it is an I-Format Control Field.

P/F - Poll/Final bit, this bit is used by the Source to solicit a response from the Destination. It is used by the Destination to respond to a solicit from the Source.

N(R) - PDU number received. Used with the Sliding Window and for acknowledging PDUs.

N(S) - PDU number sent. Used with the Sliding Window and for acknowledging PDUs.

The N(R) bits are commonly called "Piggyback Acknowledgment" because the response is acknowledged along with the transfer of data. The acknowledgement is piggybacked onto a data transfer.

In the I-Format (Information), there are no commands & responses but typically indicated by:

	I	- Information (data transfer)

Introduction to Data Communications
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