From: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> Date: Sat, 15 Nov 2008 13:11:18 +0100 > This patch deprecates the Ack Ratio sysctl, since > * Ack Ratio is entirely ignored by CCID-3 and CCID-4, > * Ack Ratio currently doesn't work in CCID-2 (i.e. is always set to 1); > * even if it would work in CCID-2, there is no point for a user to change it: > - Ack Ratio is constrained by cwnd (RFC 4341, 6.1.2), > - if Ack Ratio > cwnd, the system resorts to spurious RTO timeouts > (since waiting for Acks which will never arrive in this window), > - cwnd is not a user-configurable value. > > The only reasonable place for Ack Ratio is to print it for debugging. It is > planned to do this later on, as part of e.g. dccp_probe. > > With this patch Ack Ratio is now under full control of feature negotiation: > * Ack Ratio is resolved as a dependency of the selected CCID; > * if the chosen CCID supports it (i.e. CCID == CCID-2), Ack Ratio is set to > the default of 2, following RFC 4340, 11.3 - "New connections start with Ack > Ratio 2 for both endpoints"; > * what happens then is part of another patch set, since it concerns the > dynamic update of Ack Ratio while the connection is in full flight. > > Thanks to Tomasz Grobelny for discussion leading up to this patch. > > Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx> > Acked-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Applied. -- To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
