It's very useful for debugging to have final IP addresses of TPC transfer source and destination
Currently we have only RemoteConnections and because dCache doesn't redirect TPC client to the pool with files we don't know transfer address of active party
Proposed LocalConnection is not sufficiently generic
We decided it would be useful to have both (source + destination) addresses Perf Marker as a pair
Use new name not to break existing software (e.g. FTS/gfal/davix)
Same address format as in case of RemoteConnections
e.g. following pair "tcp:129.93.3.4:1234,tcp:[2600:900:6:1301:268a:7ff:fef6:a590]:2345"