1. You can configure the devices to send NetFlow back to the Main Solarwinds Server, or you can purchase Additional Pollers to collect and report the information back to SQL.
You can deploy 1 Additional Poller per location, or deploy an Additional Poller to cover multiple sites. Each Polling Server can handle about 50,000 Flows per second.
2. Solarwinds Additional Poller, same hardware requirements as the main Solarwinds server.
3. The amount of traffic is relative to the amount of NetFlow packets coming in, and the NPM Polling Collection. Once you have an idea about the number of incoming packets per second, you can use any NetFlow Calculator to determine the bandwidth overhead across the link without the Additonal Poller.
So it sound like I don't necessarily need remote collectors. OK. Thanks!