Transaction Descriptor Overview

The Transaction Descriptor is a mechanism for carrying Transaction information between the
Requester and the Completer. Transaction Descriptors are composed of three fields:
Transaction ID – identifies outstanding Transactions
Attributes field – specifies characteristics of the Transaction
Traffic Class (TC) field – associates Transaction with type of required service
Figure 2-12 shows the fields of the Transaction Descriptor. Note that these fields are shown
together to highlight their relationship as parts of a single logical entity. The fields are not
contiguous in the packet header.

Figure 2-12: Transaction Descriptor