After several month's of investigating asymmetric traffic flows from Glasgow to RAL, we have finally appear to have resolved the issue. Working with internal Computing Services staff at the University of Glasgow and GridPP staff at RAL we are now seeing sustained simultaneous transfer speeds around 2.3 Gig a second inbound and outbound.
The commands run for tests are shown below:
iperf -s -u -p 5001 -w 2M (client command to receive data)
iperf -d -u -p 5001 -t 600 -w 1M -c hostname -b 700M -i 30 (server command to send data)
Associated network interface card and CPU loads on device one of the tests were run.
Effectively, the Glasgow site is now an extension of the Clydenet to JANET infrastructure in the west of Scotland and we will be monitoring the services over the next month to ensure that this network solution is as stable and reliable as the previous interconnection.
In addition to this work we will be investigating in Glasgow the optimisation of the Layer2 to Layer 3 network infrastructure between ourselves, the University and the rest of Gridpp over the next 3 months.