commit cfa932f6fc683dc94a884e69712d0cf38e7b5ce4
author Victor Boivie <boivie@webrtc.org> Mon May 17 15:25:23 2021
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Mon May 17 17:41:21 2021
tree a4a04ca1d96b70b162dd8bbb7924c1f531f17077
parent 7ddadbc108918de9fb5c1d71ee71a301e6ae7f6a

dcsctp: Bump rto_min to 220 ms

The minimum RTO time shouldn't be lower than the delayed ack timeout
of the peer to avoid sending retransmissions before the peer has
actually intended to reply.

In usrsctp, the default delayed ack timeout is 200ms and configurable
using the `sctp_delayed_sack_time_default` option. In dcsctp, it's
min(RTO/2, 200ms), to avoid this issue.

Bug: webrtc:12614
Change-Id: Ie84c331334af660d66b1a7d90d20f5cf7e2a5103
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/219100
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34026}

net/dcsctp/public/dcsctp_options.h

diff --git a/net/dcsctp/public/dcsctp_options.h b/net/dcsctp/public/dcsctp_options.h
index 08893fd..4f5b50c 100644
--- a/net/dcsctp/public/dcsctp_options.h
+++ b/net/dcsctp/public/dcsctp_options.h
@@ -95,8 +95,9 @@
   // Maximum RTO value.
   DurationMs rto_max = DurationMs(800);
 
-  // Minimum RTO value.
-  DurationMs rto_min = DurationMs(120);
+  // Minimum RTO value. This must be larger than an expected peer delayed ack
+  // timeout.
+  DurationMs rto_min = DurationMs(220);
 
   // T1-init timeout.
   DurationMs t1_init_timeout = DurationMs(1000);