[RndTbl] Network performance tuning
Kevin McGregor
kevin.a.mcgregor at gmail.com
Tue Apr 6 18:36:59 CDT 2010
More results: Linux iperf client, Windows iperf server:
# iperf -i 5 -t 15 -c 192.168.27.23 -u -b 700M
------------------------------------------------------------
Client connecting to 192.168.27.23, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 126 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.27.10 port 56210 connected with 192.168.27.23 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 5.0 sec 428 MBytes 718 Mbits/sec
[ 3] 5.0-10.0 sec 408 MBytes 684 Mbits/sec
[ 3] 0.0-15.0 sec 1.22 GBytes 700 Mbits/sec
[ 3] Sent 892738 datagrams
[ 3] Server Report:
[ 3] 0.0-15.0 sec 1.16 GBytes 663 Mbits/sec 0.015 ms 47569/892392
(5.3%)
[ 3] 0.0-15.0 sec 1 datagrams received out-of-order
Reversed:
C:\Temp>iperf -u -t 15 -c 192.168.27.10 -b 750M
------------------------------------------------------------
Client connecting to 192.168.27.10, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 8.00 KByte (default)
------------------------------------------------------------
[1912] local 192.168.27.23 port 2100 connected with 192.168.27.10 port 5001
[ ID] Interval Transfer Bandwidth
[1912] 0.0-15.0 sec 174 MBytes 97.5 Mbits/sec
[1912] Server Report:
[1912] 0.0-15.0 sec 174 MBytes 97.5 Mbits/sec 1.055 ms 0/124429 (0%)
[1912] Sent 124429 datagrams
And then, running the iperf client on the same hardware as was running
Windows, but running Ubuntu 9.10 (dual boot):
$ iperf -t 15 -c 192.168.27.10 -u -b 750M
------------------------------------------------------------
Client connecting to 192.168.27.10, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 112 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.27.23 port 51363 connected with 192.168.27.10 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-15.0 sec 316 MBytes 177 Mbits/sec
[ 3] Sent 225456 datagrams
[ 3] Server Report:
[ 3] 0.0-15.0 sec 316 MBytes 177 Mbits/sec 0.207 ms 0/225455
(0%)
[ 3] 0.0-15.0 sec 1 datagrams received out-of-order
And with TCP:
$ iperf -t 15 -c 192.168.27.10
------------------------------------------------------------
Client connecting to 192.168.27.10, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.27.23 port 53251 connected with 192.168.27.10 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-15.0 sec 368 MBytes 206 Mbits/sec
The source hardware seems to be having a problem sending. Receiving, less
so:
$ iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[ 4] local 192.168.27.23 port 5001 connected with 192.168.27.10 port 37472
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-15.0 sec 949 MBytes 531 Mbits/sec
$ iperf -t 15 -c 192.168.27.23 -u -b 750M
------------------------------------------------------------
Client connecting to 192.168.27.23, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 126 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.27.10 port 37815 connected with 192.168.27.23 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-15.0 sec 1.37 GBytes 783 Mbits/sec
[ 3] Sent 999330 datagrams
[ 3] Server Report:
[ 3] 0.0-15.2 sec 1.09 GBytes 613 Mbits/sec 15.609 ms 204247/999327
(20%)
[ 3] 0.0-15.2 sec 1 datagrams received out-of-order
...Although push the bandwidth (UDP) too high, and a lot of packets get
lost.
Any further thoughts?
Kevin
On Mon, Apr 5, 2010 at 9:52 PM, Sean Walberg <swalberg at gmail.com> wrote:
> IIRC UDP needs you to pass the desired bandwidth, otherwise it defaults to
> a megabit.
>
> Sean
>
>
> On Mon, Apr 5, 2010 at 9:43 PM, Kevin McGregor <kevin.a.mcgregor at gmail.com
> > wrote:
>
>> When I choose UDP, I get
>> 0.0-15.0 sec 1.88 MBytes 1.05 Mbits/sec 6.154 ms 0/ 1339 (0%)
>>
>> No packet loss. 0.1% utilization!
>>
>>
>> On Mon, Apr 5, 2010 at 8:12 PM, Sean Walberg <swalberg at gmail.com> wrote:
>>
>>> On a LAN, window sizes aren't going to make that much of a difference.
>>>
>>> First look for the usual suspects - errors on the swich port or NIC.
>>>
>>> If you can grab a copy of the traffic, such as with tcpdump -w test.pcap
>>> tcp port 5001, you can pull it into wireshark and look for TCP zero window
>>> conditions, retransmits, and duplicate ACKs. The TCP performance graph will
>>> also show whether or not the transmission is stalling.
>>>
>>> Is the performance similar using the UDP test? Does it show loss?
>>>
>>> Sean
>>>
>>> On Mon, Apr 5, 2010 at 7:27 PM, Kevin McGregor <
>>> kevin.a.mcgregor at gmail.com> wrote:
>>>
>>>> I've been trying to narrow down where my performance bottleneck(s) is
>>>> (are). I just ran "iperf" from a Windows PC (XP SP3) to my Ubuntu 9.10
>>>> server. With iperf in "server" mode on the PC, and the client running on the
>>>> Ubuntu machine, I get
>>>> 0.0-60.0 sec 4.23 GBytes 606 Mbits/sec
>>>>
>>>> Reversed (iperf "server" running on Ubuntu server, client running on the
>>>> PC), I get
>>>> 0.0-60.0 sec 1.13 GBytes 162 Mbits/sec
>>>>
>>>> Wha...?? Both client and server runs on the PC report TCP window size to
>>>> be 8 KB, but the Linux client reports 22.4 KB and the Linux server reports
>>>> 85.3 KB. Increasing that to 256K on both ends has little effect. Does anyone
>>>> have any suggestions?
>>>>
>>>> The Windows NIC is a Realtek RTL8169/8110 Family Gigabit Ethernet; the
>>>> Ubuntu server is using the Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI
>>>> Express Gigabit Ethernet controller (rev 01). Time to replace a NIC or two?
>>>>
>>>> Kevin
>>>>
>>>> _______________________________________________
>>>> Roundtable mailing list
>>>> Roundtable at muug.mb.ca
>>>> http://www.muug.mb.ca/mailman/listinfo/roundtable
>>>>
>>>>
>>>
>>>
>>> --
>>> Sean Walberg <sean at ertw.com> http://ertw.com/
>>>
>>> _______________________________________________
>>> Roundtable mailing list
>>> Roundtable at muug.mb.ca
>>> http://www.muug.mb.ca/mailman/listinfo/roundtable
>>>
>>>
>>
>> _______________________________________________
>> Roundtable mailing list
>> Roundtable at muug.mb.ca
>> http://www.muug.mb.ca/mailman/listinfo/roundtable
>>
>>
>
>
> --
> Sean Walberg <sean at ertw.com> http://ertw.com/
>
> _______________________________________________
> Roundtable mailing list
> Roundtable at muug.mb.ca
> http://www.muug.mb.ca/mailman/listinfo/roundtable
>
>
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