Jim,
Any node can be a "HUB" A node is not limited to one connection. There may be hardware limitation about the number of connections a given piece of hardware and internet connection can support. Typically, a HUB is located on a higher bandwidth internet connection and is running a more "stout" piece of hardware. A HUB usually does not have a node radio connected to it, but there is no reason it can't. A HUB usually runs DAHDI/pseudo for it's rxchannel.

As a example HUB 2100 is running on a decent internet connection and decent hardware. We are running the beta test of the DMR <---> AllStar gateway on it so it has a NW Digital DV3000 connected and is using chan_usrp instead of pseudo for it's rxchannel.

Hope this helps.

73, Steve N4IRS

On 2/14/2016 5:24 PM, Jim Aspinwall wrote:

What if anything are the specific differences between a single node (tied to simplex, repeater, Pi box and headset...) that can presumably only accept one in-bound call/connect, and a hub, to which many can connect and bridge through/over?

Given a certain amount of specialization or purpose/interest-built hubs I am interested in having a purpose-built hub for a few systems and users not exclusive but so as not to impose on others' hubs and traffic.

What does it take to do this?