What test are you performing to evaluate bandwidth?

Knowing nothing else, I would tell you that you are using either a testing tool intended to evaluate latency for evaluating throughput, or you're basing this on an observation of latency-dependent network traffic (ping-based, snmp, or some db platforms that are really bad about this kind of thing, for example).
Make sure that you are actually using an application intended to...

I am new to postgresql, but not so new to Access. I was having the same problem in a different context, and when I started looking at this, it smelled of Microsoft Access stench. Not so sure anymore, but here goes . . .

I don't know all the details I probably ought to know about your particular situation, but it does sound at least similar to what I was facing. error 3146 from Access when linking a postgresql table with an ostensibly...