1 files changed, 14 insertions, 0 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 9b569a2d9c60..34916e792d9d 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -190,6 +190,20 @@ tcp_cookie_size - INTEGER
 tcp_dsack - BOOLEAN
         Allows TCP to send "duplicate" SACKs.
 
+tcp_early_retrans - INTEGER
+        Enable Early Retransmit (ER), per RFC 5827. ER lowers the threshold
+        for triggering fast retransmit when the amount of outstanding data is
+        small and when no previously unsent data can be transmitted (such
+        that limited transmit could be used).
+        Possible values:
+                0 disables ER
+                1 enables ER
+                2 enables ER but delays fast recovery and fast retransmit
+                  by a fourth of RTT. This mitigates connection falsely
+                  recovers when network has a small degree of reordering
+                  (less than 3 packets).
+        Default: 2
+
 tcp_ecn - INTEGER
         Enable Explicit Congestion Notification (ECN) in TCP. ECN is only
         used when both ends of the TCP flow support it. It is useful to