We have a pair of new diversely-routed 1Gbps Ethernet links between locations about 200 miles apart. The 'client' is a new reasonably-powerful machine (HP DL380 G6, dual E56xx Xeons, 48GB DDR3, R1 pair of 300GB 10krpm SAS disks, W2K8R2-x64) and the 'server' is a decent enough machine too (HP BL460c G6, dual E55xx Xeons, 72GB, R1 pair of 146GB 10krpm SAS disks, dual-port Emulex 4Gbps FC HBA linked to dual Cisco MDS9509s then onto dedicated HP EVA 8400 with 128 x 450GB 15krpm FC disks, RHEL 5.3-x64).
Using SFTP from the client we're only seeing about 40Kbps of throughput using large (2GB) files. We've performed server to 'other local server' tests and see around 500Mbps through the local switches (Cat 6509s), we're going to do the same on the client side but that's a day or so away.
What other testing methods would you use to prove to the link providers that the problem is theirs?
