One of the things I am testing is the new (so far pretty wonderful) minstrel-blues patches for linux which couples rate control with reducing power where it can, and adds a per station rc_stats_csv file that can be easily parsed by external utilities. This gives you a snapshot of the actual rate to the station being achieved, what the fallback rates are, and the probability of success.
Example stats: http://snapon.lab.bufferbloat.net/~d/minstrel-ht-stats.xls minstrel-blues info: http://www.linuxplumbersconf.org/2014/ocw/sessions/2439 Minstrel itself is the base wifi rate estimator for, I don't know, at least 1/4 billion wifi enabled devices. IMHO, most others are worse. A sad thing is that the (GREAT) paper on how minstrel actually works has never managed to get publication (it circulates as samizdat), and I really do wish more people grokked wifi rate control problems and realized that the wifi rate is never a constant, and only rarely even close to the rated specification of the device, and multicast and management frames are treated very differently from unicast. And very differently compared to the old shared pre-switched models of ethernet. Another useful set of statistics (only if you have an ath9k chip) are summaries of basic errors and aggregation stats, for each built in 802.11e compliant queue. root@minstrel-ht:/sys/kernel/debug/ieee80211/phy1/ath9k# cat xmit BE BK VI VO MPDUs Queued: 0 0 0 182 MPDUs Completed: 50453 0 0 193 MPDUs XRetried: 0 0 0 0 Aggregates: 0 0 0 0 AMPDUs Queued HW: 0 0 0 0 AMPDUs Queued SW: 50462 0 0 11 AMPDUs Completed: 9 0 0 0 AMPDUs Retried: 0 0 0 0 AMPDUs XRetried: 0 0 0 0 TXERR Filtered: 0 0 0 0 FIFO Underrun: 0 0 0 0 TXOP Exceeded: 0 0 0 0 TXTIMER Expiry: 0 0 0 0 DESC CFG Error: 0 0 0 0 DATA Underrun: 0 0 0 0 DELIM Underrun: 0 0 0 0 TX-Pkts-All: 50462 0 0 193 TX-Bytes-All: 8539213 0 0 21175 HW-put-tx-buf: 1 0 0 1 HW-tx-start: 50462 0 0 193 HW-tx-proc-desc: 50462 0 0 193 TX-Failed: 0 0 0 0 _______________________________________________ homenet mailing list homenet@ietf.org https://www.ietf.org/mailman/listinfo/homenet
