NetTest results

I’m currently troubleshooting the performance of a Navision 3.70 installation, and have among other things used NetTest. (Well, actually I have used the virtual table Performance - it seems to be almost the same). The problem is when performing large “jobs” like posting, and not in normal navigation in the application. We have done a lot of optimizations in C/AL and know that we most likely will be able to do even more. However, I would also like to investigate the hardware configuration. But I lack some information about expected values, and some indication about how much influence it has on the overall performance. I have measured about 10 installations and most results vary between 4000/900 to 5500/1200 (packets per second for 100 byte packets/4000 byte packets). However, the installation in question only reports 1500/400. It is a Citrix installation, so NetTest measures the speed between the Citrix server and the Navision server. This is a 100mbit connection, which I then suggested upgraded to a 1gb connection. However, it turns out to include quite an expensive upgrade since both the servers and network is outsourced to a third company. So now I would like to hear your recommendations with NetTest values. I have heard that the value for 4000 bytes packed at least should be 400. Is that correct, and do you have any reference or link with additional information? Is 1500/400 so low it could be a major reason for our problems? Which values would you consider normal and critical? Should the values be higher for a Citrix server than from a normal client? Do you have any performance measurements before and after the connection was improved? Do you have anything that can help me convince the decision makers to upgrade the hardware? (or to convince me that it doesn’t help much?) Thanks in advance.