[GTALUG] OpenWrt vs TP-Link Archer C7 v2

[Lennart Sorensen]

On Fri, Feb 19, 2016 at 11:53:56AM -0500, D. Hugh Redelmeier wrote:
> For a while it has looked as if the C7 v2 was a very good choice if
> one wanted to run open firmware.  In particular, it uses an Atheros
> radio that has open drivers.
> 
> Based on my criteria, OpenWrt is the firmware to run (or something based 
> on it).  DD-WRT and others have problems that make them not open by my 
> standards.
> 
> I haven't actually run OpenWrt on a C7.  But I learned a few things last 
> night that dismayed me.  You can find these in "Note:" entries on the
> wiki page but they don't stick out.
> <https://wiki.openwrt.org/toh/tp-link/archer-c5-c7-wdr7500>
> 
> 0) It is "OpenWrt", not "OpenWRT".
> 
> 1) Recent stock firmware from TP-Link locks out flashing third-party 
> firmware.
> <http://ml.ninux.org/pipermail/battlemesh/2016-February/004379.html>
> If you have a C7 with older stock firmware, don't upgrade it to the
> current stock firmware if you ever hope to use OpenWrt.  There are
> apparently work-arounds but they seem a bit intricate.

It appears to be "Don't upgrade to the current US firmware, use the
worldwide one instead".

> 2) The C7 (and a number of other routers) have a hardware fast-path to do 
> NAT.  This hardware is undocumented and hacky so OpenWrt will never use 
> it.  Without using it it is impossible to get gigabit wire-speed NATting.  
> But the stock firmware does use it.
> <https://dev.openwrt.org/ticket/11779>
> 
> 3) For mysterious reasons OpenWrt is significantly less efficient handling 
> 5GHz 802.11ac.  You won't notice this unless you are using a 3-antenna 
> client (or, I speculate, multiple 2-antenna clients)
> <https://forum.openwrt.org/viewtopic.php?id=53703>
> This thread is pretty frustrating because the first message very
> carefully posts observations and yet most of the following 168 messages
> ask questions already answered or veer off-topic.  There appears to be
> no resolution.
> 
> All this reinforces my decision to build gateways out of small
> PCs rather than consumer routers.  I do use an off-the-shelf wireless
> router as an access point.

Yeah the FCC's "That's not what we meant with our directive" is appearing
to turn into exactly what people thought it would given I don't think
the manufacturers see any other obvious way to obey the directive.

-- 
Len Sorensen