Anything odd if Receive link speed half of Transmit link?

[hagbard]

Been trying to get this answered for ages. I bought a n66u router earlier in the month, and my wireless adapter(s) tell me the Receive Link Speed is about half that of the Transmit Link Speed (300/172mpbs at 40mhz or 144/76mbps at 20mhz). I've tried different wireless adapters with the same result. Tried stock firmware and most recent Merlin, same result.

Today is the last day I can return or swap it out so I need to find out if its a hardware issue. Thanks.

BTW, my WRT54g links at 54mbps consistently. My two previous Linksys "n" routers were also consistent but very short lived, hence my concern about routers.

 

[thiggins]

What app/utility are you using to see the different up/down link rates?

 

[hagbard]

What app/utility are you using to see the different up/down link rates?

Just one of those apps that you get when you're installing a wireless adapter. This one is an Edimax app. I've had a number of wireless adapters, they all seem to come with them. The thing tells you what channel your using, IP Address, other networks in the area, signal strength, link quality, and Transmit and Receive Link rates then throughput of each.

This is the sort of think I'm talking about:

http://oi47.tinypic.com/fkco6q.jpg

 

[thiggins]

I tend to not install those and rely on Windows' built in wireless utility. Since the Windows utility provides only one number, I can't say whether what you are seeing is normal or not.

Things were much simpler in 802.11g for link rates. They got more complicated with 802.11n and way more complicated with 802.11ac.

I don't pay much attention to link rate other than to confirm that it lines up with what is supposed to be supported for the combination of router and client I'm testing. I've documented those combinations here.

 

[hagbard]

I think the overall link rate that Windows reports is 300Mbps. So I should not worry about what the wireless utility says? If you say so, I won't. I'll read through the info you provided.

BTW, I've ordered the "matching" wireless adapter Asus has for that router so I'm hoping that will clear this up.

 

[thiggins]

If Windows is reporting a 300 Mbps link rate in 40 MHz bandwidth mode from a single-band AC300 or dual-band AC600 class adapter, I wouldn't worry. You should only be operating in 20 MHz bandwidth in 2.4 GHz, however. Otherwise you hog a lot of spectrum with little incremental throughput.

 

[hagbard]

At 20ghz, I only get 144/72Mbps. but looking at your article, it appears right. So, aren't I sacrificing a lot of speed there?

 

[thiggins]

At 20ghz, I only get 144/72Mbps. but looking at your article, it appears right. So, aren't I sacrificing a lot of speed there?

That is a correct link rate for 20 MHz mode.

Link rate is one thing, actual delivered throughput is another. Average throughput improvement using 40 MHz bandwidth vs. 20 MHz is 20 - 30% under best case conditions.

 

[sfx2000]

Should also point out - wide channels are usually more impacted by range.

Additional note - wide channels not only interfere with other users in adjacent channels, they also interfere with the wide channel - so like Tim mentions - stick with 20MHz channels in 2.4GHz.

 

[hagbard]

Read the article, was very informative, thanks. Greatly lessened my concerns.

 

[hagbard]

thiggins - would using a "n' router also cause more noise over a "g" router? When check the latency between my n66u and my computer, I get mostly 1ms but occasional pings over 1000. With my wrt54g, I get almost all 1ms with very occasional 40ms pings. Judging by your article, I'd guess this would also be normal?

 

[thiggins]

802.11n does not in itself cause more RF noise. If you use 40MHz bandwidth mode, it can eat up more spectrum, which can cause noise for other networks.

You see higher latency with N because it has more modulation schemes to choose from and the AP has to keep an eye out for other networks and slower "legacy" (B/G) clients.

 

[hagbard]

Okay, well maybe my wireless stuff isn't paying nice with each other. I've noticed this morning now that I put the WRT54g back on that web pages that take a long time to load in on my system (mls.ca) are now popping up instantly with the WRT54g. All the sites I'm going to are loading without losing images or having the load spinning circle running forever. I started questioning this router because things appeared to not be right and this kind of confirms that.

 

[L&LD]

You might want to check if the RT-N66U is set to Auto instead of 'N' or 'Legacy' only.

I found a huge difference with this setting thanks to sfx2000.

http://forums.smallnetbuilder.com/showpost.php?p=95851&postcount=12


Also, which firmware are you on? The latest -36Beta1 SDK5 version is the one that works best for me.

 

[hagbard]

Yep, I tried that. Didn't help. A lot of my issues appear to have cleared up this morning since switching to the WRT54g. I took the router back at noon intending to try another but they gave me a refund. I'm going to hold back on any more wireless 'n' routers for now, I just don't have any luck with them. Will likely go completely ethernet instead.