Propose to use a SYN packet in TCP (or alike) to advertise a desired sending rate of $$X$$, and let the routers respond for or against this rate, or counter-propose another rate $$X'$$. The whole idea (a.k.a. QuickStart) is to allow a faster slow-start to catch-up the available network throughput. Once the router approves the rate of $$X$$, the sender can have a jump on the window size upon receipt of the approval message. Router would only approves the rate when it is underutilized. Simulation shows that, approval of QuickStart is just a small fraction of the overall when it is moderately congested. Also, QuickStart can only help the medium-sized flows, i.e. not the short-lived that cannot go through the slow start process and also not the large transfers that last for a significantly long time.

Other existing proposals are: (1) send a small number of packets to probe for network bandwidth (SwiftStart); (2) leveraging the capacity found by previous or concurrent sessions (FastStart). Certainly, this is useful only if history is available.

Packet pair is the technique in SwiftStart to determine the bandwidth in the early phase of TCP. But the SIGCOMM paper of Allman & Paxson (1999) suggested that it is difficult.

## Bibliographic data

@article{
title = "Determining an appropriate sending rate over an underutilized network path (ComNet 51(7))",
author = "Pasi Saralahti and Mark Allman and Sally Floyd",
journal = "Computer Networks",
volume = "51",
number = "7",
year = "2007",
}