Re: [PATCH v6 net-next 2/2] tcp: Add Redundant Data Bundling (RDB)

On 03/14/2016 02:15 PM, Eric Dumazet wrote:

On Thu, 2016-03-03 at 19:06 +0100, Bendik Rønning Opstad wrote:

quoted

Redundant Data Bundling (RDB) is a mechanism for TCP aimed at reducing
the latency for applications sending time-dependent data.

Latency-sensitive applications or services, such as online games,
remote control systems, and VoIP, produce traffic with thin-stream
characteristics, characterized by small packets and relatively high
inter-transmission times (ITT). When experiencing packet loss, such
latency-sensitive applications are heavily penalized by the need to
retransmit lost packets, which increases the latency by a minimum of
one RTT for the lost packet. Packets coming after a lost packet are
held back due to head-of-line blocking, causing increased delays for
all data segments until the lost packet has been retransmitted.

Acked-by: Eric Dumazet <edumazet@google.com>

Note that RDB probably should get some SNMP counters,
so that we get an idea of how many times a loss could be repaired.

And some idea of the duplication seen by receivers, assuming there isn't 
already a counter for such a thing in Linux.

happy benchmarking,

rick jones

Ideally, if the path happens to be lossless, all these pro active
bundles are overhead. Might be useful to make RDB conditional to
tp->total_retrans or something.