I should note that product hardware documentation doesn't appear to be Ubiquiti's strong suit. The PowerAP datasheet is surprisingly light on specs and feature descriptions and the Quick Start Guide mainly focuses on getting the right cables plugged into the correct holes.
Ubiquiti's AirOS is packed with features, however. So many, in fact, that I'm not going to try to summarize them all here. Instead, you should head over to the AirOS 5.3 Wiki, which serves as the main documentation source.
Figure 3 provides a taste of the admin GUI, which is organized around only six main screens. Also note the Tools: dropdown, which holds further delights including the AirView spectrum analyzer, which I'll get back to shortly. Web admin access is HTTP by default, but you can enable secure HTTPs connection instead.
Figure 3: PowerAP N main page
If you're a command line jockey, AirOS has you covered too, once you enable the SSH and / or Telnet servers that will get you right into BusyBox v1.11.2 .
As I mentioned earlier, the "AP" actually comes set up as a NAT router by default. All I had to do was plug it into my LAN switch like any other router I test and it grabbed a WAN address from my LAN's DHCP server and provided an internet connection to the Windows machine I plugged into one of its LAN ports before I had even located the login info (username and admin are ubnt).
I've put shots of each of the main screens into the gallery so that you can see what's there. Suffice it to say that you'll be exploring the PowerAP N's features for awhile. Despite all the goodies in AirOS 5.3, it doesn't attempt to cover all the features found in say, DD-WRT.
The biggest two omissions seem to be support for multiple SSIDs. So you don't have the ability to set up a guest network with traffic separated from your other wireless and wired clients. There is also no captive portal or hotspot features if you were thinking of using it that way.
But you do get the ability to morph the PowerAP N into an AP or non WDS or WDS bridge, which covers the major use scenarios. And you can tweak output power from its default of 27 dBm down to 13 dBm in 1 dBM increments via a slider and force specific maximum transmit rates.
The PowerAP N is also bit light on routing features, which are found under the Network menu. You get DMZ, 20 single port forward rules with separate public and private ports and TCP / UDP protocol selection. If you want to forward port ranges, you need to go to the 20 Firewall rules, which also are used for outbound service control, with the work done by iptables behind the scenes. There are no triggered port forwarding features or domain / keyword filters and no ability to schedule any of the rules, either.
I read through the description of the Auto IP Aliases feature which is part of both the WAN and LAN settings multiple times, but confess that I still don't grok what it does. I could understand that there are special NAT handlers for SIP, PPTP, FTP and RTSP, that DNS proxying can be disabled and that VLAN tags can be assigned to WAN or LAN traffic.
You also can enable Wireless Traffic Shaping and set maximum bandwidth values for traffic passing between the wired and wireless interfaces in both directions. But, again, I couldn't figure out the fractured English that described the Traffic Burst settings, sic "specify the data volume (in kilobytes) to which Outgoing Traffic Limit will not be effective afterwards data connection is initiated".
After wading through the menu tabs you still need to check out the Tools selector that launches little windows for Antenna Alignment, Site Survey,Device Discovery and Speed Test, all of which would come in handy with setting up a bridge or network of WDS partner stations. You also get Ping and Traceroute functions that you can find in even mainstream consumer routers now.
The real pièce de résistance, however is the AirView Spectrum Analyzer tool, which alone can justify the $100 or so price of the PowerAP N. It's a Java app that you might have to fiddle with your browser to get running correctly, but it's worth it.
Figure 4: AirView spectrum analyzer
As Figure 4 shows, you get real time, waveform and "waterfall" views, all of which can be handy for figuring out why your wireless has suddenly gone wonky. When you use AirView, however, the PowerAP N stops functioning as a router / AP / bridge, but resumes normal operation when you kill the AirView window.
I tested the PowerAP N with XM.v5.3 Build 7782 firmware for its routing tests. Figure 5 shows the IxChariot plots that show about 90 Mbps of routing throughput. Downlink throughput came in at 92 Mbps while uplink was slightly slower at 85 Mbps and running simultaneous up and downlink tests yielded 90 Mbps. Simultaneous Connections showed numbers indicating a 16 K session limit. Not the highest we've seen, but plenty for most P2P and gaming use.