217806 |
24-Jan-2011 |
lstewart |
Import the ERTT (Enhanced Round Trip Time) Khelp module. ERTT uses the Khelp/Hhook KPIs to hook into the TCP stack and maintain a per-connection, low noise estimate of the instantaneous RTT. ERTT's implementation is robust even in the face of delayed acknowledgements and/or TSO being in use for a connection.
A high quality, low noise RTT estimate is a requirement for applications such as delay-based congestion control, for which we will be importing some algorithm implementations shortly.
In collaboration with: David Hayes <dahayes at swin edu au> and Grenville Armitage <garmitage at swin edu au> Sponsored by: FreeBSD Foundation Reviewed by: bz and others along the way MFC after: 3 months
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