UDP on FreeBSD

[Kyungsoo Lee]

Thank you for your responses. :)


On Thu, Mar 31, 2011 at 6:45 AM, Julian Elischer <julian at freebsd.org> wrote:

> On 3/30/11 2:32 PM, Michael Proto wrote:
>
>> On Wed, Mar 30, 2011 at 3:43 PM, Kyungsoo Lee<ulsanrub at gmail.com>  wrote:
>>
>>> Hi All,
>>>
>>> I want to check UDP on FreeBSD.
>>>
>>> I am using IPERF on FreeBSD for wireless testing with Proxim 8470 FC
>>> PCMCIA
>>> card on IBM T42 and T61.
>>>
>>> When I'm transmitting data from FreeBSD to FreeBSD or CentOS using Iperf
>>> with -u -b 100M on iperf, they had lost lots of packets. Sniffer near the
>>> two nodes shows the sender could not send all packets. Iperf sender said
>>> that they try to send 85469 packets but they lost 68824 packets. I think
>>> that the UDP buffer on the sender could not handle all packets.
>>>
>>> But if I'm trying to send data from CentOS to FreeBSD using Iperf with -u
>>> -b
>>> 100M option on iperf, the sender tries 18636 packets so they lost few
>>> packets like 1 or 2 packets.As a result, they have similar bandwidth
>>> result
>>> on the report. I think that it happens from different implement between
>>> FreeBSD and Linux.
>>>
>>> But I want to double check that this is normal for FreeBSD or not. If I
>>> have
>>> some missing points, let me know please.
>>>
>>> Thank you!
>>> _______________________________________________
>>> freebsd-net at freebsd.org mailing list
>>> http://lists.freebsd.org/mailman/listinfo/freebsd-net
>>> To unsubscribe, send any mail to "freebsd-net-unsubscribe at freebsd.org"
>>>
>>>  Just a guess, but have you tried adjusting the net.inet.udp.maxdgram
>> sysctl? I believe the default is somewhat low for UDP transmit. I
>> don't know what size packets iperf is using but increasing the
>> maxdgram value might help your testing.
>>
>
> this is many years out of date but a decade or so ago freebsd would return
> ENOBUFS
> and linux would block when the outgoing queues filled up.
> the answer then was that teh programs are all written for Linux and didn't
> check for ENOBUFS
> but that may be out of date now in many different ways.
>
>>
>> -Proto
>>
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>>
>>
>