1. In a multi-processing system having a first endpoint device coupled to a second endpoint device via an interconnect, a method for managing transaction transfers, comprising: creating a priority system in both the first endpoint device and the second endpoint device for the exchange of transaction information in the system wherein: (1) requests for transaction information that require a response can never be issued at the highest priority; (2) no endpoint device may allow the acceptance of input transaction information to be contingent on outputting transaction information of equal or lesser priority than the input transaction information; (3) highest prioritized transaction information must be able to be serviced before lower prioritized transaction information when lower prioritized transactions can not make forward progress; and (4) for transaction information of a same priority level, transaction information is serviced on a first-in, first-out basis; in the first endpoint device, implementing a request transaction of the second endpoint device; transferring the request transaction from the first endpoint device to the second endpoint device via the interconnect; and in the second endpoint device, implementing the request from the first endpoint device.