When I did enterprise Wi-Fi on a daily basis, my mindset was that enterprise wireless was the only “real” Wi-Fi. Home routers were cheap toys, and only wimps used a router supplied by their ISP. As I’ve aged (and gone to work for a “residential Wi-Fi” company), I have become less judgmental.
In this article, I break down three types of devices that broadcast 802.11 wireless.
Access Points (APs)
In the enterprise world, we talk about access points (APs). Access points are typically layer-2 devices that convert between an 802.11 wireless connection and a wired connection (typically Ethernet). Some of the players that pop into my head in this arena are: Cisco/Meraki, Juniper, Extreme, Aruba, Ruckus, and Ubiquiti. There has been a lot of consolidation over the years (the one that affected me the most was Cisco buying Airespace back in 2005). The M&A efforts continue, as HPE/Aruba has been trying to buy Juniper for over a year as I write this.
More often than not, APs are controlled centrally by a non-cleverly (but appropriately named) device: the Controller, sometimes called a WLAN or Wi-Fi Controller. Many pages could be written about what controllers do, but they aren’t in the title of this post, so that’ll have to wait for another post.
Routers
In the residential world, it’s unusual to have a device that is simply an AP, as defined above. Instead, we have “Wi-Fi Routers,” which typically provide:
- Wi-Fi access point functionality
- Layer-2 switching capabilities via one or more LAN interfaces
- Layer-3 routing capabilities via WAN interface
- DNS and DHCP server services
- NAT and firewall services
- etc.
Some players off the top of my head in that space are: Netgear, Linksys, and D-Link. Sometimes you can also get “mesh units” (aka, satellites—not to be confused with the ones that orbit the earth) that have either a Wi-Fi or an Ethernet connection back to the main router that extends connectivity to an area larger than can be handled by a single device. These devices don’t typically have a lot of intelligence of their own (or their intelligence is disabled), but they are smarter than the dumb “Wi-Fi repeaters” that you can sometimes find.
Residential Gateways
A third category that most Wi-Fi professionals don’t really think about is the Residential Gateway (RG). These are similar to “Routers” above, but are usually owned by the Internet Service Provider, and “call home” via:
- Centralized ACS (Auto Configuration Server) using:
- TR-069, aka CWMP (CPE* WAN Management Protocol)
- TR-369, aka USP (User Services Platform)—the successor to TR-069
- Proprietary management platform, typically using https for transport
- Hybrid approach where as much as possible is done via TR-x69, but certain shortcomings necessitate a secondary connection for the necessary flexibility
* CPE: Customer Premises Equipment
In addition, because they are supplied by service providers, they may have POTS ports (for landline phones) and sometimes even an F-type coax connector to support “triple play” internet/phone/cable TV service. Some vendors that come to the top of my mind for this are: Calix, Plume, Nokia, and Adtran.
There are some vendors who play in both the “router” and “RG” world, for example, Plume and Eero (owned by Amazon).
Thoughts on Nomenclature
Based on the things written above:
- An RG is always a router *
- A router is always an AP †
- By implication, an RG is always an AP †
* assuming it isn’t just acting as a layer-2 passthrough
† assuming Wi-Fi isn’t disabled
So, what do you call a router (which I will call a system here) if it’s doing “non-residential” things? For example, what if a system has three SSIDs:
- SSID-1 is configured to pass transparently through the device at layer-2 like a traditional AP
- SSID-2 is tied to the system’s internal DHCP server, and traffic gets NAT’ed as it passes through
- SSID-3 routes but does not NAT, and acts as a DHCP relay rather than a DHCP server
When it’s advertising SSID-1, should we call it an AP, when we’re referring to SSID-2, is it an RG, and when it’s doing SSID-3, is it a router?
My thought is that we should refer to it based on the context of what we’re describing. If we’re talking about Wi-Fi connectivity, we refer to it as an AP. If we’re talking about its router or NAT functions, we call it either a router or an RG–depending on if it’s primary configuration responsibility is that of the ISP or the person who owns or leases the device.
Some examples might be:
- Access Point
- “The AP is set to channel 36 with an 80 MHz width”
- “We can roam seamlessly between those APs”
- Router
- “What IP does that router NAT outbound connections behind?”
- “Does that router have OSPF enabled?”
- Residential Gateway
- “What phone number is tied to the SIP configuration on that RG?
- “Can you check the parental control settings using the iOS app for your RG?”