Methods and apparatus for transacting multiple data flows between multiple processors. In one such implementation, multiple data pipes are aggregated over a common transfer data structure. Completion status information corresponding to each data pipe is provided over individual completion data structures. Allocating a common fixed pool of resources for data transfer can be used in a variety of different load balancing and/or prioritization schemes; however, individualized completion status allows for individualized data pipe reclamation. Unlike prior art solutions which dynamically created and pre-allocated memory space for each data pipe individually, the disclosed embodiments can only request resources from a fixed pool. In other words, outstanding requests are queued (rather than immediately serviced with a new memory allocation), thus overall bandwidth remains constrained regardless of the number of data pipes that are opened and/or closed.