I find it curious that packet aggregation is done in 802.11n standards, but that the packets are limited to 1540. I bet that limit may not be there in all Atheros NICs, and maybe not in this one. Will investigate now that I'm curious.
-----Original Message----- From: "Robert Bradley" <[email protected]> Sent: Friday, June 22, 2012 4:41pm To: [email protected] Subject: Re: [Cerowrt-devel] Fwd: [PATCH] ag71xx: Added support for baby-jumbo packets. On 22/06/12 21:11, [email protected] wrote: > Good step. Why not allow 9K byte jumbos when one's packets traverse a path > that is internal to the local area, and all the 1 GigE links support 9K? > All the posts I could see claim that the System-on-Chip NIC (Atheros AR7161) cannot handle packets greater than 1540 octets, so routing 9k packets from wired->wireless or wired->WAN would not be an option. If I understood Dave's previous post correctly, though, the built-in switch allows jumbo packets, so wired->wired internal traffic should work fine with 9K packets already. The only issue with that setup is that with mismatched MTUs, it might be impossible to communicate with the router and the 9k-friendly nodes at the same time. Thankfully, on Linux at least, you can set per-route MTUs (http://lartc.org/howto/lartc.cookbook.mtu-discovery.html), so it might be possible to exploit that to do what you want. Maybe something like this would work? ip route add default via 172.30.42.1 mtu 1500 ip route add 172.30.42.1/32 dev eth0 mtu 1500 ip route add 172.30.42.1/27 dev eth0 mtu 9000 -- Robert Bradley _______________________________________________ Cerowrt-devel mailing list [email protected] https://lists.bufferbloat.net/listinfo/cerowrt-devel _______________________________________________ Cerowrt-devel mailing list [email protected] https://lists.bufferbloat.net/listinfo/cerowrt-devel
