Impact on TCP Standard NewReno Flows

From WiL

The idea is to perform tests over a dumbbell topology and compare the performance of

1. one execution of N homogeneous TCP NewReno flows, and afterwards, using the same seed,
2. one execution of a mixed TCP NewReno + New Protocol flows, where there are N/2 TCP NewReno flows.

As the "New Protocol" replaces half of the NewReno flows, it aims to improve the overall utilization (by a certain amount G), but on the other hand, it could harm the throughput (by a certain amount L) of the co-existing NewReno in doing so.

Camp A and camp B. For each flow from Camp A, another with same RTT (etc) from camp B at almost the same time (plus/minus a small offset). First case: Camp A and Camp B use NewReno. Second case: Camp A uses new protocol and Camp B uses NewReno.

Outputs

• ?Two numbers: throughput of camp A and camp B
• One possibility: breakdown with respect to flow sizes?

Controversial points:

• The same seed is the warranty that the same environment will be run in the two executions and thus the only difference is the protocol itself.

Round-Table Discussion:

• Sally pointed out in the literature review, a "Bandwidth taken from TCP" concept [1], slide 8, as a possible metric to evaluate the impact of new protocol on TCP. Cesar complemented saying that he found other proposals similar, in nature, in his literature review. There was an extra clarification on making the proper distinction between "measure of shareness on mixed flows scenario" by using some fairness metric AND the "measure of the impact", the actual metric described above.

Agreed on:

• None yet.

Todo:

• Couple the amount G and L in a either a single metric "L/G"?, or use a 2-D graph to represent the tradeoff of G and L?
  • Consensus was 2-D graph.
• What would be a reasonable range on which L could be reduced?