hello johnson,
from my personal experience, when tring to utilize high bandwidth links,
the bottleneck in not the network but the endstations themself,
please observe the following points:
1. check that the end stataions not busy doing other tasks then the file transfer.
2. in order to fully utilize OC3 on the WAN, the endstations should be connected at 1G at the LAN.
check that there are no other bottlenecks between the endstations and the wan.
(if you want to utilize 100M on the WAN, so 100M NIC is enough - but make it full duplex)
3. it can be the fact that your are working with a "real" file transfer protocol,
those protocols have bottlenecks, for example:
- they are utilizing slow hard disk access.
- FTP for example have 4096 byte buffer size.
- TFTP have insufficiant flow control mechanisms.
- TCP window size can reach its limit.
those are just examples, have more protocols that each have its own drawbacks.
depand on which protocol you use, you should check its potential bottlenecks. OR, the better way,
you can use test tools that will workaround those problems,
those test tools are kind of traffic generators, my faivorate is Chariot of NetIQ,
it is software based and it simulates the real transport protocols.
you can use a hardware traffic generator, but be carefull with that if you are doing tests on a live network.
if you don't have such equipment you can run the test from few endstaions in paralel.
if you will make long enough test and run in at the same time, you might have resolts that will satisfy you.
I hope I gave you some ideas about what should you do, if you didn't solve the problem,
give me more details and we will see if we can work this out.
Galit.
