path: root/net/dccp/ccids/ccid2.h
diff options
authorSamuel Jero <sj323707@ohio.edu>2011-07-24 20:49:19 -0600
committerGerrit Renker <gerrit@erg.abdn.ac.uk>2011-08-01 07:52:35 -0600
commitd346d886a4c7f771c184e73833133f23a18de884 (patch)
treeb30d5ea65d37af5dd49f03712ae2f973bc71553b /net/dccp/ccids/ccid2.h
parentdccp ccid-2: use feature-negotiation to report Ack Ratio changes (diff)
dccp ccid-2: prevent cwnd > Sequence Window
Add a check to prevent CCID-2 from increasing the cwnd greater than the Sequence Window. When the congestion window becomes bigger than the Sequence Window, CCID-2 will attempt to keep more data in the network than the DCCP Sequence Window code considers possible. This results in the Sequence Window code issuing a Sync, thereby inducing needless overhead. Further, if this occurs at the sender, CCID-2 will never detect the problem because the Acks it receives will indicate no losses. I have seen this cause a drop of 1/3rd in throughput for a connection. Also add code to adjust the Sequence Window to be about 5 times the number of packets in the network (RFC 4340, 7.5.2) and to adjust the Ack Ratio so that the remote Sequence Window will hold about 5 times the number of packets in the network. This allows the congestion window to increase correctly without being limited by the Sequence Window. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Diffstat (limited to '')
1 files changed, 6 insertions, 0 deletions
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index f585d330e1e5..18c97543e522 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -43,6 +43,12 @@ struct ccid2_seq {
#define CCID2_SEQBUF_LEN 1024
#define CCID2_SEQBUF_MAX 128
+ * Multiple of congestion window to keep the sequence window at
+ * (RFC 4340 7.5.2)
+ */
* struct ccid2_hc_tx_sock - CCID2 TX half connection
* @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5