Need expert networking help...this is a head scratcher for me.

YBS1

Golden Member
May 14, 2000
1,945
129
106
I'm out of ideas as to what could be causing this issue so I will try to explain it as exact as I can.
I recently purchased an Asus AC66U router. I'll go ahead and lay out the problem right here: I cannot get decent transfer speeds from my HP EX495 MediaSmart Windows Home Server to the two pc's that are connected via an AC bridge. All this testing was carried out using single large mkv/mp4 files. I am absolutely not in a crowded wireless area (especially on the 5GHz band as I can't even pickup another in the area even faintly). The AC bridge is only about 20 feet (same floor) from the AC66U router.

The WHS is obviously connected to the AC66U via wired connection to get that out of the way and has a 1gbps ethernet port.

To begin with I started off with the AC66U and a WD MyNet AC Bridge to which the two pc's are connected. I could send data to the WHS at a good ~20MBps, with a beautifully straight transfer line, I'll go ahead and state in all scenarios that follow the speed from the AC connected pc's to the WHS is the same ~20MBps with a nice flat transfer, no peaks, no valleys. Transfers from the WHS to the pc's however was all over the place, jumping up and down wildly anywhere from 42MBps down to 1MBps, usually averaging about 9MBps. Just horrible. Of course I tried different firmwares and settings on the AC66U, all with the same results.

I came to the conclusion the AC66U was defective on the 5GHz AC channel and ordered a replacement. Again, I got the same results as the original AC66U. So my attention turned to the WD MyNet AC Bridges (I should note I used them before I actually received my AC66U with my old Netgear WNDR3700 and they worked wonderfully. ~12MBps up/~20MBps down, awesome for an N300 router.), I assumed possibly something with the WD's and the Asus router just might not be getting along correctly so I decided to use the original AC66U in it's bridge mode. Again...same result, so it wasn't the WD's. I should add here that I installed an Intel 82574L pci-e gigabit nic in one of the pc's just to eliminate the possibility of one or both of the pc's onboard nic's not being up to snuff. Same thing. Also, have tried other network cables.

So now my attention turned to the HP WHS and it's onboard nic. So I decided to try taking the wireless out of the equation just to see if the HP was up to the job. Success! The WHS had no problem pushing data at ~77MBps to the wired pc, right about at the read limits of the 2TB green drives it uses. At this point I was starting to think wireless ac just isn't what it's cracked up to be, and the Asus router is at fault.

I decide to try just one more thing to see if it's just that wireless AC isn't capable of the kind of transfer speeds it should be. I decide to hard wire an Asus laptop to the router and test the transfer speeds from it to the pc's connected via AC bridge. Success again! 20MBps to the laptop from the AC bridge and a very healthy ~35-45MBps from the laptop to the AC connected pc's with no wild swinging up and down throughout the transfer.

So the question is.....Is there anything that sticks out in anyone's head as to what would cause the issue only with transfers from the WHS to the AC connected pc's?
 

Jamie0

Junior Member
Aug 24, 2013
1
0
0
Hi - I just registered to try and help with this... :p

Are you able to put one of the WD AC bridges on the server [as the sole wireless interface], and the router on one of the PCs [again, as the sole interface for wifi], to effectively reverse the traffic "direction" [of course all connections are two-directional, but I hope you understand what I'm asking].

The potential fly in the ointment would be if the router is dependent on the server (or vice versa) for DHCP utility... In which case you might have to set up an ad-hoc network with both devices as clients, which would be lots of faff. Hopefully though, you can just swap the router to one of your PCs, and put the WD AC bridge on the server.

Let me know what, if anything, changes in the functionality.

Reason: the first that springs to mind is some kind of strange eccentricity of Windows home server and/or any compression or traffic management settings from HP and/or how it is handling packets, such that the AC bridge is struggling to communicate with either the server [or the router/server together], through the existing connectivity. I wonder if the AC bridge may better be able to communicate when it's sat at the HP server end of the conversation.

Possible causes of the issue in my mind are: how the server is handling the packets, how the router is handling the packets, or how the bridge is handling the packets -- with a mindset of "something here is doing something to the data flow that is confusing the heck out of one of the other links in the chain; causing either (i) massive queueing (ii) lots of check/recheck/rerecheck (iii) dropped packets/problems with compression".

With 802.11ac being such a new technology, with a variety of chips, firmware etc, the potential for hiccups is about as high as it can be (for a set of technologies that in theory, should "just work").
 

YBS1

Golden Member
May 14, 2000
1,945
129
106
I never remembered to update this for the sake of anyone who might be having the same issue and stumbled upon the thread.

Apparently it's related to the original WHS. The issue disappeared completely after switching to WHS 2011. Sustained transfers to and from the WHS now are where they should be.