On the SQM part for high bandwidth connection:
But once you get above couple hundred mbps internet speed, bufferbloat doesn't seem to be an issue at least for today. I suppose once 4k streaming becomes mainstream there will be need for sqm on > ~300mbps service.
ipq8065 in wireless client mode with nat and firewalls disabled has a ~30% SIRQ doing 140mbps transfer. A low end chip with 4x4 ac radio may not be able to handle the throughput.
Clearly you don't do much VOIP 
I need more education on this - I shape in the uplink direction at ~11mbps but left downlink alone. Games like CSGO is working good - how is VOIP requirement different from that of say a real time online game (which incidentally also has in game voice chat that I don't seem to have a problem with)?
Perhaps you have a DOCSIS 3.1 connection with built in bufferbloat management?
In my experience, either games or VOIP both have pretty strong real-time latency requirements. Packets shouldn't be delayed more than say 5ms under load.
On my gigabit fiber connection, un-managed, the bufferbloat easily results in 750ms delays during speed tests. So, yes I need some kind of queue management. Now, I understand some of the more modern cable connections already have some kind of bufferbloat management either in the modem or the head-end and so you may not experience those kinds of delays. Or, you may not actually be using your connection anywhere near its peak capacity, so buffering doesn't occur and you haven't noticed the issue.
I guess it depends heavily in the typical usage in a home. In speedtest yes you can actually saturate a 300 mbps connection downstream rather easily, but for me specifically I use one dedicated wireless AP for myself for gaming, and have another wireless AP for everyone else.
When the total wireless throughput without traffic shaping is below ~300mbps, I guess it's technically not possible to get bufferbloat in the gateway router without some other ethernet wired device hogging the link.. In this case though I also do ~100mbps shaping for the wireless AP to avoid bufferbloat from wifi link congestion.
Remember that TCP is a two-way communication. The more you load your upstream, the later the ACKs are, until that becomes the limiting factor. I have, on several occasions, unwittingly maxed-out a 30 Mbps upstream link, which brings everything to a halt.
Yep, but for example if you tell windows to download a windows update, or you try to update a Debian/ubuntu machine or you try to grab a large file off Google Drive or whatever, and the device is wired so WiFi isn't a bottleneck, then you WILL max out the downlink, and get bufferbloat unless it's taken care of in your modem or head-end or via some ISP queue management solution somewhere.
EDIT: and as jeff said, also you can max out uplink and then delays in ACK will stall TCP connections. Though if you're doing uplink management correctly then this won't happen.
Yeah thats right. Thats why:
Haha thats right. It's just that for my place every client goes through some wireless link(s) in daily use. The only wired devices are AP, switches and routers.
I'm not sure if you're blessed or cursed, I have several wireless links that support more than the 400 Mbps that my Archer C7's CPU can manage.
I'm not sure how this discussion managed to get derailed and evolve around "bufferbloat" and other issues.
Going back to the original post, my research so far shows that Realtek and Lantiq chipsets are the cheapest in the market but there are issues around OpenWRT/LEDE compatibility and even if there are FLOSS drivers, the functionality of the embedded WiFi chipsets is not as good as QCA. Have you guys had any experiences?
I also checked the Alibaba routers, most of them are really poorly designed, they don't have dual-band antennas, they look horrible. Seems to me not a professional job.
You ask about ideal spec for low cost router. The fact is today many people have sufficiently fast connections that there is nothing that works well other than maybe an ARM based system or an x86 particularly when you need queue management, which IMHO is always. That's how.
It's no good getting something that doesn't meet the real requirements even if it's cheap.
I would want a way to unbrick it if flashed wrong like the Linksys wrt1900ac, etc. Ideally a way to boot off a second ROM and Flash either for the common case and TTL cable support for big problems. If users can screw it up, we will.
Most of all I would want open support so we can run the latest drivers instead of binary blobs. I want the new airtime fairness scheduler work! This means either mt76 or ath10k. Signs point to the mt76 being the more open, so pick that.
Beyond that it is just a matter of cost. As long as it is inline with similar spec routers loaded with closed firmware I'll gladly pay a small premium for this. Especially if a portion of the proceeds directly go to supporting the project.
I respectfully disagree, I think there are very capable low cost ($30 to $80) routers that can handle the 100Mbps (and more, maybe up to 300Mbps) that even the most advanced users would need today. Going up to $200+ for x86 routers is for hobbyists playing with faster connections and misses the forest.
Thank you, great answer!
Here is a thought, instead of Flash soldered on to the board why not removable storage? If anything goes wrong just plug it into your PC and re-Flash.
Boot off usb would also be another potentially useful feature so one can unbrick the router easily.
I prefer it if my router storage didn't have legs and that no one could just install a new image by popping in a usb as they walked by.
Not to mention speed
why is your router physically accessible to random people walking by who might pop in a new flash? Oh yes, probably because it also acts as a wifi access point and so its location needs to be favorable for RF... which brings up a good point.
Routers should be separate from access points.
So, assuming we're trying to route and shape less than say 50 Mbps so that we don't have to have an argument about cpu power, I still think it makes good sense to have an all-wired router, something with a WAN port and 4-6 LAN ports, and YES a removable micro-sd storage. Something that uses not very much power, and can be locked in a cabinet.
Let WiFi come from access points placed at favorable locations.