Re: [UDT] UDT with congestion control

[Harald s. <sc...@rv...>]

Hello Yunhong,

Thank you for your answer.
I have also tried the scalable, hstcp and BIC congestion contol
algorithms as they are defined in cc.h.
Every time i get a performance of 0.2 MB/s.

For example, i activated scalable with:
UDT::setsockopt(client,0,UDT_CC,newCCCFactory<CScalableTCP>,sizeof(CCCFac=
tory<CScalableTCP>));
Is there anything more to do? What may be the reason for the poor
Performance?

Thanks in advance,
Harald


> Hi, Harald,
>=20
> Once you uncomment the -DCUSTOM_CC option, the default UDT congestion=20
> control algorithm will not be used any more.
>=20
> Default window size in UDT is 16 packets and it will not change unless =
you=20
> assign a new congestion control algorithm.
>=20
> Once you specify CTCP, you are using TCP's AIMD algorithm, which usuall=
y=20
> does not work well for long distance links (you mentioned that RTT is=20
> 100ms).
>=20
> Thanks
> Yunhong
>=20
>=20
> On Thu, 2 Mar 2006, Harald schwier wrote:
>=20
> > Hello,
> > i'm doing some performance tests with UDT. Without changing
> > any options, appclient shows 950 MB/s (1GB Ethernet, RTT about 100ms).
> >
> > After i uncomment the -DCUSTOM_CC compile option in ./src/Makefile
> > and recompile the library the Performance goes down to 1.7 MB/s witho=
ut
> > changing any Options in appclient.
> >
> > When i change the socket options with:
> > UDT::setsockopt(client,0,UDT_CC,newCCCFactory<CTCP>,sizeof(CCCFactory=
<CTCP>));
> > the performance goes down to 0.2 MB/s.
> >
> > UDT 2.3
> > Compiled with: make -e os=3DLINUX arch=3DAMD64
> >
> > What may be the reason for the poor performance???
> >
> > Thanks in advance,
> > Harald
> >
> >
> >
> >
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Mit freundlichen Gr=C3=BC=C3=9Fen,
Harald Schwier


--=20
Dipl.-Ing. Harald Schwier          D-30159 Hannover
Lehrgebiet Rechnernetze            Schlosswender Str. 5
RRZN, Universit=C3=A4t Hannover         Tel: +49 (511) 762 7919081
Fachbereich Informatik