WiFi burst rate vs. net IP layer speed - again

[stevech]

In the engenious bridge review, it is said

It is interesting to note that the EnGenius advertises the ENH500 with a max data rate of 300 Mbps, but with only 10/100 Ethernet connections, you're going to be limited to 100 Mbps for any connection that goes from the wireless network to the wired network. We'll see in the Performance section that the 10/100 port does in fact limit maximum throughput.

Isn't it the case that most vendors advertise speed based on the WiFi burst rate? That is so misleading to consumers. The net IP layer speed is often 60% or so of the burst rate - because of WiFi duplexing overhead, forward error correction, media access delays, and so on.

 

[azazel1024]

Yes, but it makes it especially worse when you have a product with 10/100 ports on it and anything over 150Mbps single band or non-concurrent dual band.

The statement about going WLAN to LAN or just LAN to WLAN isn't entirely wrong. An 841nd I have has 10/100 ports and I've tested duplex speeds of around 160Mbps on it using 2.4GHz 40MHz mode. Roughly 85Mbps down and 75Mbps up at the same time. Max single direction traffic was/is about 92Mbps on it. I've also tested performance between two wireless clients through the 841nd and also received around 140Mbps or so transfer speeds half-duplex (example transfering from my laptop to my brothers laptop, both wireless and both connected to the 841nd).

So there are some situations where the port doesn't limit things, because it isn't going through the port. However, a TYPICAL use case will find the port being the limiting factor and that is annoying.

I don't know what full switch BOM costs are for a 5 port gigabit switch, or a 4+1 for a router, but I am pretty darned sure it is tiny. I know the cost for a gigabit Intel NIC for a motherboard is on the order of 90 cents and something like Realtek NIC are in the area of 30 cents or so. So I'd imagine the difference between a 10/100 5 port internal switch for a router over a gigabit Marvel, Broadcom, etc. 5 port internal switch has gotta be on the order of a dollar or two maybe. If that.

Now, maybe it is also a SOC issue, where the SOC needs to have a high enough speed interface for the radios and switching module to actually interlink at gigabit speeds, and that is an extra cost there too, but still bothers me.

It doesn't bother me when you are paying $20 for a router and it is only 10/100 ports. It does bother me when you are paying $60+ for a range extender with client mode and it is only 10/100 ports...or you are paying $80+ for an outdoor wireless bridge and it only has 10/100 ports.

 

[Razor512]

While there is a good chance that in the real world, you would never hit 100mbit/s if using these devices to create a wireless bridge at a distance where Ethernet is not a cost effective option.

I bet it would not even hit 50mbit/s real world throughput at any of the distances it was designed for. Other than that, they really should not be using 100mbit Ethernet.

 

[htismaqe]

I have an old Netgear WNHDE111 AP and people used to make a big deal about the fact that it only has 10/100 ethernet ports.

It's most common use was as an N150 client bridge, there's no way the ethernet ports were really that much of a bottleneck.

 

[azazel1024]

While there is a good chance that in the real world, you would never hit 100mbit/s if using these devices to create a wireless bridge at a distance where Ethernet is not a cost effective option.

I bet it would not even hit 50mbit/s real world throughput at any of the distances it was designed for. Other than that, they really should not be using 100mbit Ethernet.

Depends on what you mean on designed for distance.

That 841nd I was mentioning with the 10/100 ports saturates the ports in 40MHz mode at ~120ft when I connect my laptop to it (2:2). I run it in 20MHz, other than testing, but it is just a plain jane N300 router with 5dBi omnis. I'd imagine with 13dBi panel antennas on both ends and much more powerful radios you could easily get a "port limited" link at several hundred feet (if not more).

Granted, you probably won't get a port limited link at several thousand feet, but I'd consider a wireless bridge "in its element" at anything at 100ft or greater (and plenty of people use them for 20-40ft links because they just can't run a cable for whatever reason).

PS Please note, my 841nd N300 router is port limited in 20MHz mode when connecting my laptop at close to medium distances. I mean, hell, my indoor AP/routers in 20MHz mode would be port limited to. My WDR3600 (if I set it in 20MHz mode) can hit 108Mbps and my Archer C8 can hit 116Mbps in 20MHz mode. With overhead, a 100Mbps port is really only capable of around 88-92Mbps...so...yeah, even in 20MHz mode with another N300 client, a 100Mbps is often limiting, even if it isn't exactly strangling the connection.

Other than "cheaping out" I think the ONLY time a 10/100 port is resonable is either 11g or older gear, or an N150 router/AP. Anything faster and odds are good that the port is going to be the limiting factor in some/many cases and considering the likely tiny cost differential, that doesn't seem resonable to me to market an N300+ product with only 10/100 ports, even if it means driving the price on that $20 router to $23 or something to do it.