Date: Fri, 17 Feb 2006 09:59:47 -0800 From: Sam Leffler <sam@errno.com> To: =?ISO-8859-1?Q?Sten_Daniel_S=F8rsdal?= <lists@wm-access.no> Cc: freebsd-net@freebsd.org Subject: Re: ATH max packet size? Message-ID: <43F60F13.6000805@errno.com> In-Reply-To: <43F599BF.7080004@wm-access.no> References: <43F599BF.7080004@wm-access.no>
next in thread | previous in thread | raw e-mail | index | archive | help
Sten Daniel Sørsdal wrote: > I am still waiting for my PCI -> MiniPCI bridge for my CM9 card so i am > unable to test this, and even though i read the source i am still > unsure, so i was hoping a kind generous soul would answer my question; > > What is the max packet size (mtu) available using the ath driver? > > The reason i ask is, i want to setup a tunnel between two units and > optimally not have to deal with any fragmentation issues. > From net80211/ieee80211.h: /* * Maximum acceptable MTU is: * IEEE80211_MAX_LEN - WEP overhead - CRC - * QoS overhead - RSN/WPA overhead * Min is arbitrarily chosen > IEEE80211_MIN_LEN. The default * mtu is Ethernet-compatible; it's set by ether_ifattach. */ #define IEEE80211_MTU_MAX 2290 #define IEEE80211_MTU_MIN 32 ath can actually handle very large packets (64K I believe) but the current driver won't chain rx descriptors together so it's limited to an mbuf cluster (2K). Sam
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?43F60F13.6000805>