From jnkernel 1.31, there will always be a statistics log file in joinnet folder for a meeting session.
The file name is in the format of
stat_log_xxxx_xx.txt
where xxxx is the year, and xx is the month

If JoinNet doesn't have access to write log file in joinnet folder, the statistics log file will be written to temp folder

The statistics log files that are of more than one year old will be deleted by JoinNet automatically.

Each line in the statistics log has the format of
Thu Dec 13 17:56:01 (0:02,135289) xxxxxx
where 0:02 is the hour:minute since the meeting start time
135289 is the millisecond since the meeting start time

A meeting session's statistics log always starts with a line of
==================== 1542038966 ====================
where 1542038966 is the anchor number, which can be used to find the corresponding joinnet session in the joinnet log file
in this example, the corresponding joinnet log file will contain a line
4968:2.750	 statistics log anchor 1542038966
This number can be used for easy cross reference between the joinnet log file and statistics log file

Other lines have the following meaning and format:
*** when joinnet is connected to a mcu
connected with mcu 67.19.188.75[67.19.188.75]:443

*** when joinnet uses TCP for media, and there is data sent out to mcu, there will sth. like
tcp_media_rate_control,worst_command = 1,targetrate = 54000,queue=0(0 + 0)
this shows how the rate control decide the sending target rate (every 2-5 seconds)
where worst_command could be 1(to increase target rate); 0(keep same); -1(to decrease target rate)
targetrate: the new sending target rate for video
queue=t(a+b): t is total queue size, a is storage buffer size, b is active sending buffer size

*** when joinnet uses UDP for media, and there is data sent out to mcu, the rate control is done by mcu, joinnet will show sth. like
rate_control,worst_command = 1,targetrate = 54000
where worst_command could be 1(to increase target rate); 0(keep same); -1(to decrease target rate)
targetrate: the new sending target rate for video

*** appdata recving,
appdata_recv_rate(channel 1),54000
this shows that appdata at channel 1 is recving at 54000bps

*** appdata sending
appdata channel 1, data rate 54000 -> 56000
this shows that appdata at channel 1's sending rate is changed from 54000bps to 56000bps

*** audio recving
audio_recv_rate(channel 1,ssrc 1) 54000

*** audio loss rate
audio_loss_rate(channel 1,ssrc 1),2345
user ssrc1 at channel 1 has audio loss rate of 23.45%

*** audio jitter
audio_jitter(channel 1,ssrc 1),13423(unit: 1/100ms)

*** total recv rate
total_raw_audio_recv_rate,54000
total_raw_video_recv_rate,54000

*** video recving
video_recv_rate(channel 1,ssrc 1),54000

*** video loss rate
video_loss_rate(channel 1,ssrc 1),2345
user ssrc1 at channel 1 has video loss rate of 23.45%

*** appdata recving
appdata_recv_rate2(channel 1),54000

*** audio sending rate (udp)
audio_send_rate,7543

*** video sending rate (udp)
video_send_rate,54000

*** audio sending rate (tcp)
audio_send_rate,7517,queue=141(0 + 141),avg=0
queue=t(a+b),avg=c: t is total queue size, a is storage buffer size, b is active sending buffer size, c is average queue size

*** video sending rate (tcp)
video_send_rate,54000,queue=0(0 + 0),avg=0
queue=t(a+b),avg=c: t is total queue size, a is storage buffer size, b is active sending buffer size, c is average queue size

*** appdata sending
appdata_send_rate,54000