Re: UDP receiver getting more than the sender is sending .

[John S. E. <jes...@nc...>]

Nirav, regarding the original question (below), the report is at least
consistent: the number of MB transfered is seen as equal (333 MB) by both
client and server, however, the time interval for the calculation is
slightly different, hence the calculated bandwidth slightly differs.

Offhand I don't know why the intervals differ. I'd suggest perusing the 
archive to see if this is a known issue.


On Tue, 23 Mar 2004, nirav jasapara wrote:

> Is it because the UDP sender is retransmitting packets and not counting those 
> in its bandwidth calculations while the receiver is considering all incoming 
> packets ?
> 
> -- Nirav.
> 
> ----- Original Message -----
> From: nirav jasapara <jas...@us...>
> Date: Monday, March 22, 2004 6:08 pm
> Subject: UDP receiver getting more than the sender is sending .
> 
> > Hi,
> > 
> > i am runnning iperf for some performance tests between two machines 
> > connected 
> > via a crossover cable. Strangle my UDP receiver ( 341 Mbps ) shows more 
> > Bandwidth then my sender ( 279 Mbps ).
> > <>
> > 
> > [jasapara@node0 ~]$ ./iperf -c 10.1.4.2 -u -B 10.1.4.3 -b 280M -w 256K
> > ------------------------------------------------------------
> > Client connecting to 10.1.4.2, UDP port 5001
> > Binding to local address 10.1.4.3
> > Sending 1470 byte datagrams
> > UDP buffer size:  256 KByte (WARNING: requested  256 KByte)
> > ------------------------------------------------------------
> > [  5] local 10.1.4.3 port 32775 connected with 10.1.4.2 port 5001
> > [ ID] Interval       Transfer     Bandwidth
> > [  5]  0.0-10.0 sec   333 MBytes   279 Mbits/sec
> > [  5] Server Report:
> > [  5]  0.0- 8.2 sec   333 MBytes   341 Mbits/sec  0.082 ms  124/237342 
> > (0.052%)[  5]  0.0- 8.2 sec  19879 datagrams received out-of-order
> > [  5] Sent 237342 datagrams
> > 
> > <>
> > 
> > How is that possbile ?
> > 
> > Thanks
> > - Nirav.
> > 
> > 
> > 
> 

-- 
John S. Estabrook
jes...@nc...
jes...@da...