We have six sites connected to TW Telecom's iLAN service. Site A has six T1's and site B has three T1's. During off hours we have attempted to copy large files from site A to site B and vice versa. We rarely get over 1 Mbps and never over 1.5 Mbps. The test was performed as follows:
1. Create large 300MB file with TrueCrypt (so it's exactly 300MB).
2. Use robocopy to copy from a server in site A to a server in site B.
3. Use robocopy to copy from a server in site B to a server in site A.
4. Repeat 10+ times.
5. Repeat several times a week.
6. Calculate average.
We had a meeting with TW Telecom and they told us the protocol used to bond the T1's is MLPPP (multi-link PPP) and that the performance we are seeing is normal for one session (TCP stream). The traffic we're concerned about the most is server-to-server file transfers.
Is there a different bonding protocol we can use to load balance the session? Is there a device we can install in between the sites (like Riverbed or Silver Peak) that can load balance better? Obviously those devices will improve performance, but ideally, we would want to do something very low cost, since the iLAN service already costs so much. I have researched MLPPP a bit, but haven't found a definitive answer about the one stream per physical connection.
Any help and/or links to technical documentation on the subject would be greatly appreciated.