cp5555 / cp Goto Github PK

[Description]
This is an implementation of Cutting Payload (CP) method, a complementary method of TCP to maintain self-clocking and achieve accurate and rapid packet loss notification. 

The implementation is based on Linux 2.6.38.3. The detailed information of CP is described in the paper "Catch the Whole Lot in an Action: Rapid Precise Packet Loss Notification in Data Centers", presented at NSDI 2014. 

The paper is available online at 
http://qos.cs.tsinghua.edu.cn/~chengp/papers/CP_NSDI2014_PAPER.pdf

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[Authors]
Peng Cheng, Tsinghua University

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[How to Apply Patch]

(1) Download the patch from 

(2) Download the Linux Kernel 2.6.38.3
	#wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.38.3.tar.bz2
	#tar jxvf linux-2.6.38.3.tar.bz2

(3) Install the patch
	#cp cp-2.6.38.3-v1.0.patch linux-2.6.38.3
	#cd linux-2.6.38.3
	#patch -p1 < cp-2.6.38.3-v1.0.patch

(4) Compile and install the kernel. CP doesn't need any special kernel configuration.

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[How to Enable CP]

(1) Basic Settings for CP:
	#sysctl -w net.ipv4.tcp_congestion_control=reno
	#sysctl -w net.ipv4.tcp_sack=1
	#sysctl -w net.ipv4.tcp_cp=1
	#sysctl -w net.ipv4.tcp_pack=1
	
(2) Optional Settings:	
	<1> Change the send and receive buffer memory for achieving 1 Gbps throughput. 8MB is large enough for both buffer. You can reduce them depending on your experimental environment:
	#sysctl -w net.ipv4.tcp_wmem="8388608 8388608 16777216"
	#sysctl -w net.ipv4.tcp_rmem="8388608 8388608 16777216"
	
	<2> DSACK (1-Open 0-Close):
	#sysctl -w net.ipv4.tcp_dsack=1 
	
	<3> DCTCP (tcp_dctcp_enable: 1-Open 0-Close):
	#sysctl -w net.ipv4.tcp_ecn=1
	#sysctl -w net.ipv4.tcp_dctcp_enable=1
	#sysctl -w net.ipv4.tcp_dctcp_shift_g=4
	
	<4> Delayed ACK (1-Open 0-Close):
	#sysctl -w net.ipv4.tcp_delayed_ack=0
	
	<5> Set RTO_MIN (ms):
	#sysctl -w net.ipv4.tcp_rto_min=200
	
	<6> Set the number of tolerable out-of-order packets.(tcp_disorder_max: 1-infinity 0-tcp_reordering):
	#sysctl -w net.ipv4.tcp_disorder_max=0
	#sysctl -w net.ipv4.tcp_reordering=3

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[Changelog]

2014 Feb. 28 - v1.0
2014 Mar. 20 - v1.1 - Add comments for reading. Delete all test code.