I/O or CPU bandwidth issue or wget issue or perhaps isp???

[JD]

fc16 (latest updates) + wget-1.12-4.fc16.i686, and system load 
negligible when I start wget.
CPU is Athlon64 3700+ (but I run i686 kernel/apps).

Sometimes, wget chokes


25% [+++++=====>                              ] 1,000,855,688 --.-K/s  
eta 27m 57s

even though I can actually start another download in a a separate terminal)
of the same file from the same server with no delays, which in turn after
a while chokes as above. The download speeds fluctuate as low as a few 
hundred
Kbytes/s  to 2.70 Mbytes/s. It usually chokes when it reaches the high 
end of
download speeds.

I have measured my disk i/o throughput using dd from one drive (on the 
internal
eide bus) to the external eSATA drive connected to system via a dual 
port eSATA cardbus.
The speed ranges from 20 to 27 megabytes/s.

The wget download goes to the external eSATA drive /dev/sdb, on 
partition sdb5 (7200 rpm).

So, I am at a total loss with the reason why this is happening (and 
frequently within the last few days).

Also, during wget runs, iostat -chm 5

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           15.64    0.00   14.80   13.74    0.00   55.81

Device:  tps    MB_read/s    MB_wrtn/s    MB_read    MB_wrtn
sdb     7.82         0.00         1.94          0          9
sdb1    0.63         0.00         0.01          0          0
sdb2    0.00         0.00         0.00          0          0
sdb3    2.54         0.00         0.04          0          0
sdb4    0.00         0.00         0.00          0          0
sdb5    4.65         0.00         1.89          0          8

shows no obvious bottlenecks during 2.2 mbyte/s download speed snap shot.

Does anyone have an idea what I should be monitoring in order to see
the event that is leading to this?
As I stated above, it does not seem to be the server because I can
immediately start another transfer of same file from same server without
seeing any delays.
By the way, I am not ruling out the ISP as the cause of the hickup.

Finally, ultimate reason I am posting this issue is because wget seems 
to remain
in the chocked state and does not simply close the connection and 
immediately open
a new one. Yesterday, it remained in the chocked state all night, until I
interrupted wget and restarted the download (with -c of course) in the 
morning.