Network performance degradations on Access points

[NetMan32]

I'm managing a small network composed as described in picture.

The point is about a performance degradation when any device connects to routers (acting as Access points). The loss of download speed is about the 10/15% (it happens always, with only one device connected to AP too). If I connect the device directly to the switch this kind of loss doesn't occur.

On one AP router I've mantained stock firmware, on the other one I've installed open-wrt firmware but with same results, so it shouldn't be a firmware problem.

Both AP routers have DHCP server disabled and static Ip configured on.

Is this a normal behaviour?

 

[ColinTaylor]

What is the make and model number of the AP's?

Does the speed degradation happen with both wired and wireless clients connected to the AP?

What is the absolute change in speed (in Mbps)?

 

[NetMan32]

The APs are:

1)Lynksys wrt32x
2)Fritzbox 4020

Here I'm talking about the speed on wired clients. For wireless client the situation is much worse.
Tests are done with only one client wired to AP.

The speed on main router (and directly from switch) is about 100/110 Mbps. Speed from APs is about 90/85 Mbps.

NOTE:Just to make you understand, on wifi connections (being very close to the AP) the speed is around 50 Mbps on Lynksys and 20/30Mbps on Fritzbox.

 

[ColinTaylor]

From what I can see on the internet the Fritzbox only has 10/100 Mb Ethernet so 90 Mbps of actual throughput once you have accounted for overheads would sound about right. It is also a 802.11n device so I would expect to see WiFi throughput of about 70 to 90 Mbps depending on the client and whether there any other nearby AP's causing interference.

There appears to be two versions of the Lynksys wrt32x "gaming router", one of which has "Killer networking". In my experience anything that uses Killer networking is a massive red flag as it invariably ends up causing network problems. I looked at the user manual for each of them and it's next to useless. Does your Linksys have a dedicated "access point" mode or are you still running it in router mode (but using the LAN port)?

 

[NetMan32]

My Linksys has killer network and hasn't an access point ethernet dedicated. Btw, It doesn't have the possibility to disable DHCP server out of the box. For this reason I flashed OpenWRT firmware on it.
On both APs I used one of the 4 ethernet ports to connect AP to router (via switch).
So basically degradation experienced isn't normal, isn't it ?

 

[ColinTaylor]

No that doesn't sound normal, apart from the Fritzbox's wired speed which probably is.

Examine the Ethernet indicator LED for the switch port the Linksys is plugged into. Make sure it is negotiating at 1000 and not 100.