Hi.
Just curious, what would you choose if you were starting new wisp. Which authentication service, which routing protocols, which equipment etc.
pppoe, ospf, eoip tunnels and mikrotik with ubiquiti 
Mikrotik routers with ospf, mpls with vpls tunnels, DHCP and ubiquiti radios
Auth: PPPoE with a RADIUS Manager
Network: OPSF/BGP/MPLS with VRF and TE riding on a tagged Layer 2 infrastructure
Equipment: Depends on bandwidth requirements but at least 2011 for core and 751G for the edge. MaxxWave also makes great RouterOS platforms.
bgp for external routing especially if you are going to multihome, ospf for internal, cloud core for the core router hp switches, the ones that run the 3com os, everywhere else with saf or trango backhauls, ubiquiti air fiber if the shots are short enough for 23-24ghz and it doesnt rain too much where your at. FreeRadius dhcp and dns all on a fully redundant linux server with an identical replacement kept off site but ready to go, also do the same for the cloud core. For the last mile of delivery I’d go with cambium gear, its more expensive but absolutely the best gear I have ever dealt with insanely low failure rate incredibly knowledgeable customer support, and being able to reuse frequency due to cambiums proprietary gps timing is a god send. The 2.4ghz pmp 450 platform should release soon and they are claiming 40 mile ranges with reflector dishes, also cambium 2.4 pmp 100 gear has excellent tree penetration and I expect it should be just as good if not better with the 450 platform due near line of sight capabilities of the 450 platform. We’ve used gear from redline and ubiquiti in the past and cambium beat it hand over fist in nearly every way. It can also authenticate with freeradius.
Sorry if i come off as a bit of a cambium fanboy but they have earned my loyalty for a reason.