Download IPv4 vs. IPv6 Performance over Satellite Links

UNIVERSITI SAINS MALAYSIA
IPv6 throughput over
Satellite links (update)
Data collection by: Ezrin, Bukhary, CH Tang
Tat Chee Wan ([email protected])
Network Research Group
School of Computer Sciences
University of Science Malaysia
11800 Minden, Penang, Malaysia
June 2003
AI3 Tokyo, JP Meeting
1
UNIVERSITI SAINS MALAYSIA
Satellite Link Expt Setup
• USM & Temasek Polytechnic via AI3 network
– 2 hops
– 512 kbps end-to-end (forward and reverse links)
•
•
•
•
Dual Stack native IPv4/IPv6 links
FreeBSD 4.5
Netperf for IPv6 support
IPv4 and IPv6 TCP/UDP tests
June 2003
AI3 Tokyo, JP Meeting
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UNIVERSITI SAINS MALAYSIA
Satellite Link Configuration
1.5 Mbps
512 kbps
1.5 Mbps
512 kbps
512 kbps
512 kbps
1.5 Mbps
512 kbps
end-to-end
USM (4.5m)
June 2003
JP (6.0m)
Temasek Polytechnic (4.5m)
AI3 Tokyo, JP Meeting
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Terrestrial Link Expt Setup
• Terrestrial Link tests done in NRG:
– NRG leased-line to TMNet (512 kbps)
– USM leased-line to Jaring (4 Mbps)
[Firewall blocks IPv6 traffic]
• IPv4 tests between TMNet and Jaring
• IPv6 tests using tunneling to MANIS (tunnel
•
•
•
broker) via TMNet
FreeBSD 4.7
Netperf for IPv6 support
TCP tests only
June 2003
AI3 Tokyo, JP Meeting
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Terrestrial Link Configuration
MANIS
IPv6 Tunnel Broker
TMNet ISP
IPv4 Network
512 kbps
IPv6 Tunnel
to MANIS
4 Mbps
Jaring ISP
NRG
USMNet
Node A
TMNet IP
June 2003
Node B
Jaring IP
AI3 Tokyo, JP Meeting
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Experiment Parameters
• Default FreeBSD 4.5 Buffer sizes
– TCP sendspace=32K, recvspace=64K
• Setting window size in FreeBSD
– sysctl net.inet.tcp.sendspace=<windowsize>
– sysctl net.inet.tcp.recvspace=<windowsize>
• Results averaged from A->B & B->A
readings
June 2003
AI3 Tokyo, JP Meeting
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TCPv4 Performance over Two Hop Satellite Link
(Averaged)
400.00
Throughput (Kbps)
350.00
300.00
250.00
100K
500K
200.00
1M
150.00
2M
2M (Linux/Apr '02)
100.00
50.00
0.00
0
50
100
150
Window Size (KB)
June 2003
AI3 Tokyo, JP Meeting
7
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TCPv6 Performance over Two Hop Satellite Link
(Averaged)
200.00
100K
180.00
Throughput (Kbps)
160.00
500K
140.00
1M
120.00
100.00
2M
80.00
2M (TCPv4)
60.00
40.00
2M (TCPv6 Linux/Apr
'02)
20.00
0.00
0
50
100
150
Window Size (KB)
June 2003
AI3 Tokyo, JP Meeting
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UDPv4 Performance over Two Hop Satellite Link
900.00
800.00
Throughput (Kbps)
700.00
IPv4 (USM->TP)
600.00
IPv4 (TP->USM)
500.00
400.00
IPv4 Linux/Apr '02
(USM->TP)
300.00
IPv4 FreeBSD/Apr
'02 (TP->USM)
200.00
100.00
0.00
0
2000
4000
Message Size
June 2003
AI3 Tokyo, JP Meeting
9
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UDPv6 Performance over Two Hop Satellite Link
600.00
Throughput (Kbps)
500.00
IPv6 (USM->TP)
400.00
IPv6 (TP->USM)
300.00
IPv6 Linux/Apr '02
(USM->TP)
200.00
IPv6 FreeBSD/Apr
'02 (TP->USM)
100.00
0.00
0
2000
4000
Message Size
June 2003
AI3 Tokyo, JP Meeting
10
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TCPv4 Performance over Terrestrial Link
(Averaged between 512 Kbps & 4 Mbps links)
400.00
Throughput (Kbps)
350.00
300.00
250.00
100K
200.00
500K
1M
150.00
2M
100.00
50.00
0.00
0
50
100
150
Window Size (KB)
June 2003
AI3 Tokyo, JP Meeting
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TCPv6 Performance over Tunneled Terrestrial Link
(Averaged A->B & B->A over 512 kbps link)
Throughput (Kbps)
700.00
600.00
100K
500.00
500K
400.00
1M
300.00
2M
200.00
2M (TCPv4 Avg)
100.00
2M (TCPv4 Jaring>TMNet)
2M (TCPv6 Sat)
0.00
0
50
100
150
Window Size (KB)
June 2003
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Observations/Comments (1)
• FreeBSD 4.5/4.7 has identical performance for
TCP traffic over IPv4 and IPv6 via satellite link
– TCPv4 for Linux (RH 7.1) appears to scale better
(from previous results)
– TCPv6 for Linux (RH 7.1) had worse performance
compared with FreeBSD 4.5: immature IPv6 stack?
• UDP performance over satellite is too variable to
draw any conclusion
June 2003
AI3 Tokyo, JP Meeting
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Observations/Comments (2)
• Firewall causes TCPv4 to have low throughput
– TMNet->Jaring (firewall) low throughput (~150 kbps)
– Jaring->TMNet high throughput (> ~500 kbps)
– Averaged value (~350 kbps) for comparison purposes
• TCPv6 performance over terrestrial link still
exceeds that for Satellite link
– Terrestrial IPv6 link is tunneled
– Terrestrial & Sat links are both 512 kbps (end-to-end)
– ~400 kbps (terrestrial) vs ~150 kbps (satellite)
• UDP performance not tested for terrestrial link
June 2003
AI3 Tokyo, JP Meeting
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Conclusions
• FreeBSD 4.5/4.7 TCP protocol not affected
by v4 vs. v6 transport
• Linux (RH 7.1) seem to have more
aggressive TCPv4 performance
• TCPv6 performance over high latency links
is very poor
June 2003
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Thank You
Q&A
June 2003
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Apr 2002 Presentation
(Previous results)
June 2003
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Experimental Setup
• Linux RH 7.1 for USM
• FreeBSD 4.3 for Temasek Polytechnic
June 2003
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18
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TCP v4 Stream Test with various Transfer Size
500.00
Throughput (Kbps)
450.00
400.00
100KB
350.00
500KB
300.00
1MB
250.00
2MB
200.00
2MB (1 Hop)
150.00
100.00
50.00
16
June 2003
48
80
112
Window
Size
(KByte)
AI3 Tokyo,
JP Meeting
144
19
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TCP v6 Stream Test with various Transfer Size
Throughput (Kbps)
350.00
300.00
100KB
250.00
500KB
200.00
1MB
2MB
150.00
2MB IPv4
100.00
50.00
16
June 2003
48
80
112
Window
Size
(KByte)
AI3 Tokyo,
JP Meeting
144
20
UNIVERSITI SAINS MALAYSIA
Throughput (Kbps)
UDP Stream Test with 64KB Socket Buffer Size
(USM->TP)
550.00
450.00
350.00
IPv4
IPv6
250.00
150.00
50.00
0
2000
4000
6000
8000
Message Size (Byte)
June 2003
AI3 Tokyo, JP Meeting
21
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Throughput (Kbps)
UDP Stream Test with 64KB Socket Buffer Size
(TP->USM)
550.00
450.00
350.00
IPv4
IPv6
250.00
150.00
50.00
0
2000
4000
6000
8000
Message Size (Byte)
June 2003
AI3 Tokyo, JP Meeting
22
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Comments
•
•
TCP Throughput in each direction is consistent for
standard packet size (MTU < 1500 bytes)
UDP Throughput:
–
–
–
•
for USM->TP is better for IPv6 (MTU>1500 bytes)
for TP->USM is better for IPv4 (MTU>1500 bytes)
Different IP Fragmentation setting in routers?
IPv6 performance is not optimal over Satellite Links
–
–
–
Need IPv6 stack optimization (KAME?)
TCP throughput is not improved with larger window size
(> 32K): TCPv6 ssthresh not configured?
Support for jumbo frames?
June 2003
AI3 Tokyo, JP Meeting
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