TCP/UDP Stacks Testbed

Ruchi Gupta and Les Cottrell. Created September 24th 2004

Description

These tests have been desgined to determine how fair various transport protocols are. Currently we are experimenting with:
High-Speed TCP
Hamilton TCP
Scalable TCP
Layered TCP
Reno TCP
HSTCP-LP
UDP based Data Transport (UDT)

Design

We run a volley of 4 TCP/UDP flows, one after the other each separated by an interval of 2 minutes. Each flow leaves in LIFO (last in first out) order. As shown in the figure below, the test is broken up into 7 regions, and statistics are collected for each of the seven regions as well as per individual flows. Aggregate throughput values are also collected for each of the regions as well as for the overal test.

Flow 1 is represented by RED
Flow 2 by GREEN
Flow 3 by BLUE
Flow 4 by PINK

Parameters

	Caltech	UFL	CERN
RTT ms	13.6	78.9	164
Bottleneck Mbps	600-1000	400-600	400-700
Window Size	16MB	16MB	16MB

Also the following line was added in /etc/sysctl.conf for the sender and receiver. These values are used as default unless specified otherwise:
net.core.rmem_max = 33554432
net.core.wmem_max = 33554432
net.core.rmem_default = 65536
net.core.wmem_default = 65536
net.ipv4.tcp_rmem = 4096 87380 33554432
net.ipv4.tcp_wmem = 4096 65536 33554432
net.ipv4.tcp_mem = 33554432 33554432 33554432
net.ipv4.route.flush = 1

Results

tr>

	Caltech	UFL	Cern
HSTCP
HTCP
HTCP v4
Scalable TCP
FAST TCP
LTCP
LTCP - new
Reno
HSTCP-LP
HSTCP-LP latest
BICTCP
UDT
UDT NEW with NIC adj.
UDT NEW with NIC adj. and windowing

Summary and Analysis

server utilizaiton: 39.802u 456.054s 16:27.60 50.2% 0+0k 0+0io 0pf+0w UDT server utilization flow 1: speed = 255.262Mbits/sec 31.603u 191.797s 17:16.71 21.5% 0+0k 0+0io 0pf+0w flow 2: speed = 474.891Mbits/sec 48.868u 263.643s 14:57.16 34.8% 0+0k 0+0io 0pf+0w flow 3: speed = 80.3762Mbits/sec 6.574u 38.833s 13:00.44 5.8% 0+0k 0+0io 0pf+0w flow 4: speed = 304.034Mbits/sec 13.312u 60.251s 10:55.04 11.2% 0+0k 0+0io 0pf+0w utilization = (sum(user-time) + sum(sys-time))/flow1's real time? = 9.68 % ... surprising speed = 125.128Mbits/sec 32.420u 164.620s 58:19.83 5.6% 0+0k 0+0io 223pf+0w speed = 166.981Mbits/sec 138.340u 207.060s 56:16.42 10.2% 0+0k 0+0io 223pf+0w speed = 33.2805Mbits/sec 9.030u 28.590s 54:53.42 1.1% 0+0k 0+0io 372pf+0w speed = 53.9548Mbits/sec 59.000u 43.130s 52:38.42 3.2% 0+0k 0+0io 224pf+0w