Hacker News Reader

Comment by nominated1 | Hacker News Reader

The MediaTek MT7621 SoC has support for hardware NAT in OpenWrt. The driver is being developed by Felix Fietkau of ath9k fame who has stated that it’s the most open (blob free) 5Ghz chip on the market. I’ve been using an mt7621 device since before the Lede split and the progress has been amazing. If you’re reading this Felix, thank you!!

I haven’t been following the development branch but the current stable branch says “Experimental feature. Not fully compatible with QoS/SQM”. For this reason I haven’t enabled it.

EDIT: My decision to go with the mt7621 came from watching the rant by Felix on wireless drivers. https://youtu.be/hiUosbhR0Wo

View on HN

We once tried to develop a repeater at 7628, and it turned out to be a disaster. Mediatek's platform support just does not exist for anybody buying less than 1m chips.

Everybody else are footballed to regional partners who can't do a thing. Their official BSP is a fork of 2.4... No userspace tools can work with their drivers that essentially run their own IP and MAC stack. But even their own tools are not sufficient to config things, communications with them often went like "put byte A1 into secret register B and arm watchdog beforehand just in case it crashes."

Is this "hardware NAT" something that's closed in the hardware/firmware, or is it specialized hardware that is programmable with open source to implement NAT in some kind of accelerated way?

(I don't care as much as the FSF does, about where closed behavior is represented -- downloadable blob from host, on-device storage, or burnt into hardware. What's more important to me is getting more of the behavior represented in open source/hardware.)

(BTW, I love the Linux ath9k work. Besides various routers and PCIe WiFi cards, I have a stockpile of Corebooted ThinkPads in which I've replaced the mini-PCIe cards despite the original whitelisting.)

I’m not an expert but as I understand it, many chips have hardware offloading (what I referred to as Hardware NAT). However, it’s bundled into a closed blob. Meaning it may only work with the kernel it was developed against and that it can’t be modified.

However, the mt7621 has the smallest closed blob and exposes enough for open development of hardware offloading. It’s this same access that allowed for the great ath9k and is what is allowing for a great mt7621.

You're confusing the wireless interface with the Ethernet one. The Ethernet driver that implements hardware offloading uses no firmware.

The UniElec U7621-06 is interesting: https://openwrt.org/toh/unielec/u7621-06

I would be interested in a 5G "as open as possible" chip. I was considering the RTL-881x family before (https://github.com/nazar-pc/rtl8814AU and https://github.com/astsam/rtl8812au) but a standalone ath9k like the AIRETOS AEX-AR9590-NI could be even better.

Where did you buy your device? It's not on ebay or amazon.

Reply on news.ycombinator.com