William A Pohlchuck

Tests referenced in 5/9/2019 posts were run using cfdptest.

DTN2 150 Mbps transfer

On board g/w running DTN2. Two simultaneous 75 Mbps streams.

Some additional testing was performed. Instead of using ION on the on board DTN gateway, DTN2 was used. So the architecture was On Board Endpoint (ION) <---- TCP CL ---> On Board DTN G/W (DTN2) <--- LTP ----> Ground DTN G/W (DTN2) <---- TCP CL ----> Ground Endpoint (ION). Using DTN2, no drop off in rates was observed (e.g., configured for 80 Mbps LTP downlink rate and sent consistently at 80 Mbps). See attached figure (ISS_DTN2_190423a.jpg) showing the space to ground bandwidth using DTN2 for both...

Figure 3 shows the comparison of a 1 GB file transfer using "bpsendfile" (first section on plot) and CFDP (second section on plot).

Figure 2 shows the completion of one transfer and start of another. New transfer starts at the rate of the previous transfer.

Figures illustrate the rate drop off.

ION Rate Dropoff During CFDP Transfer