Hi everyone. I'm a long time lurker and Tomato user, but first time poster. So I would like to thank everyone who has worked on Tomato and TomatoUSB — my friends & I really appreciate your work.
Now then, I've spent almost all weekend attempting to configure a network setup in my new apartment to allow me to connect one of the bedrooms to the main router (in the living room) so that I can connect multiple wired-only devices (my desktop PC, a network printer, and an Xbox 360) to the main subnet of my network. Thus far, my attempts have been failures because when I ping from a client connected to the secondary router to the main router's local address I'll get lots of 1-2 ms responses, followed by a seemingly random 3000+ ms response or a complete timeout of the ping request, which occurs during 5-10% of the pings).
The only setup that works is using wireless client mode instead and placing WRT on a different subnet, which I discuss more below. First here's my setup and a summary of what I've tried:
Environment & Equipment: Large basement apartment in 3-story house built in 1915 (thin walls all around)
Cable Modem < — > (wired to) RT-N16 < — > (wirelessly connected to) WRT160v3
Currently both routers are running v1.24.7482 MIPSR2-Toastman-RT (mini version for WRT, NVRAM60K-VPN-NOCAT for RT-N16)
Things I've tried that haven't worked:
1) Changing channels: I've determined that channel 1 has by far the least interference here. The intermittent high latency problem occurs much more often when I set the channel to 6 or 11.
2) Adjusting transmit power: I've tested the RT-N16 from 12 mW to 60 mW (and numerous values in between) and the WRT from 2 mW to 42 mW, and various combinations of each, with no meaningful effect. Generally, I've found that raising transmit power on both routers increases average ping, but doesn't seem to affect the frequency of the spikes.
3) Adjusting various other advanced routing settings: Notably I tried enabling/disabling WLAN interference mitigation settings, as well as WMM, but I couldn't find a combination to alleviate the issue (although there are many combos I haven't tried because of the sheer number of possibilities).
4) Changing router firmware: I've tried both routers with multiple versions of Tomato and DD-WRT (including the well reputed Brainslayer 14929 build). Perhaps one mistake in my methodology is that I usually made sure that both routers were running the same firmware version because I thought that would minimize potential variables to troubleshoot. I meticulously did a 30/30/30 before & after each firmware change.
5) Changing each of the routers one at a time with a Netgear WNDR3300 running DD-WRT 15962: The intermittent latency spike occurred when the Netgear router was taking the role of each router.
6) Trying modes other than wireless ethernet bridge: I tried WDS (in both Tomato & DD-WRT) & Repeater Bridge (in DD-WRT) with no change in spike occurrence.
7) Switching the WRT from Gateway to Router mode: under wireless ethernet bridge mode, I would assume that Router mode is the correct mode to be in, but switching between the two seems to have no effect on this problem.
8) Changing the RT-N16 from Auto wireless mode to N-Only or G-Only: I seem to get the lowest pings and most stable LAN throughput with G-Only on the RT-N16 and the WRT set to Auto (oddly, it gets worse pings when it is set to G-Only, no matter which wireless mode is selected). However, no setting is able to eliminate bridging latency spikes. Additionally, I use the 20 Mhz band in all modes as it seems to be the most stable.
The one thing that DOES work: Using wireless client mode (works in both Tomato & DD-WRT). Average ping to main router is usually 1-2 ms with a max value of roughly 15ms (taken from 600 ping tests).
If I can't find a better solution I'll have to settle for using this mode and keeping the bedroom on a separate subnet. I've encountered problems with port forwarding/NAT translation that are limiting the functionality of some PC apps, as well as strange behavior in some games on Xbox Live (unless I place the Xbox 360 in the DMZ of BOTH the RT-N16 & WRT), so this solution would force me to try to find a way to deal with those problems. Also, my network printer would then only be accessible to my desktop PC, but I would like it to work for wireless clients of the main (RT-N16) subnet as well.
So my questions are: Is there a reason why wireless client mode works so much better than the single subnet solutions? Is it simply a matter of single subnet modes becoming crippled by interference while client mode is relatively immune, or have I missed a crucial setting that would stabilize ethernet bridge mode?
And, if using wireless client is my only viable solution, is it possible to change settings or write a script in Tomato that would either disable the 2nd firewall from the WRT router or otherwise allow me to fix the port forwarding/NAT issues clients behind the WRT subnet are having?
Thanks in advance.