Notes from the GGF15 BOF on Data Transfer.

Task: copying file hierarchy from A to B.
- something has to check that sufficient space exists
- do all source files exist?
- what if the file hierarchy is a DAG?

Need separate interface for file system operations.

Copy semantics.
- At least once.
- Possibly at most once?
- Copy to at least n sites from a list >= n.
- Specifying number of retries or alternatively time by which transfer should complete

Clean up on error?

Transfer control 
- extensible for different protocols
- limit bandwidth use

Naming
- abstract names or addresses?  CERN resolves abstract names to replicas as part of this service.