The best rate to get from ATLAS's SONAR test involving RAL can be assumed to be internal transfers from one Space token at RAL to another space token at RAL. The Sonar plot for large files; (over 1 GB,) for the last six months is:

Averaging this leads to:

Leading to average of 18.4MB/s as the average rate with spikes in 12 hour average to above 80MB/s. (Individual file transmission rates across the network (excluding overhead) have been seen at over 110MB/s. This relates well to the 1Gbps NIC limit on the disk servers in question.

Now we know that of Storm,dCache,DPM and Castor systems within the UK that Castor tends to have the longest interaction overhead for transfers. Overhead for RAL-RAL transfer varies for the last week is between 14 and 196 seconds with an average of 47 seconds and a standard deviation of 24 seconds.