Sry, 903 MBit/sec Transfer Speed , not Gbit :-)
Am 19.02.2020 um 12:10 schrieb Stefan Rinass:
  Hi,
 i hope this is the right place regarding my question..
 I have problems with a Netjack connection between two Machines
 whenever, as it seems, a certain amount
 of channels are being added and i cannot figure out the cause.
 Machine 1 runs Ubuntu Eean and Ardour 5 on a I3-3210 with 4 GB RAM and
 a huge swap (just to avoid running out of memory)
 Machine 2 runs W7 on a i5-4570, 8GB of RAM with Jack Netdriver
 (1.9.11)  and a rather old Version of FL Studio, using Jack Netrouter
 as audio Device, unsing onboard Audio
 Jack Netdriver on the Windows side is so configured that it offers 2
 capture channels and 32 Playback channels in Async mode.
 Jack on the Server side (Ubuntu) runs in RT (also tried non-RT)
 2048/2, 44.1 KHz
 Link between both is 1 GBit/sec. Afaik bow cards are idenitified as
 RTL8169.
 First problem:
 - transferring more than two audio channels simultaneously usually
 leds into "stutter" on Ardour.
 Second Problem:
 -transferring Audio over more than 10 Channels kills JackD immediate
 on the server side. Log is on the end of this mail.
 Done an iperf(3) between both machines shows no sign of Packet loss 
 (TCP and UDP), Transfer speed is about 903 GBit/sec. Ping is between
 0.2 and 0.3 msec
 Tried with different MTU´s on both sides between 1500 and 9000, before
 i replaced my old Slave machine with the I3 it sometimes helped to
 switch between 1500-900-1500 while Playback of the Slave machine to
 get rid of the stutter.
 I also recompiled JackD on the master machine from 1.9.12 to 1.9.14
 with additional DBUS-support, but it doesn´t make any difference.
 Firewalls are off while testing. also killed Pulseaudio.
 Tried to turn off anything which has to do with Speedstepping, set
 with cpufreqd everything to "performance", no success at all. Even
 fillding around with sync, async, different Buffer sizes, periods-  no
 chance.
 Yes, according to the log i recognize the missing data packets, but
 have no clue what could be the cause - Jack itsef, the Jack Netdriver
 on the Windows side....
 Before Ardour connects to Jackd, i also get a lot of
 "ProcessGrapMasterASync"-Errors....and sometimes in between.
 Any help would be greatly appreciated, because i run out of ideas....
 Best regards
 Stef
 Logs:
 //
 ....<lots of missing Data packets>...
 Wed Feb 19 10:48:31 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:31 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 10:48:32.602 XRUN callback (16 übersprungen).
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:32 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 10:48:33.176 Schaubild der JACK-Verbindungen geändert.
 10:48:34.104 Schaubild der JACK-Verbindungen geändert.
 Wed Feb 19 10:48:33 2020: Disconnecting 'bla2-PC-01:from_slave_7' from
 'ardour:OBXDLR/audio_in 1'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:33 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:34 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:34 2020: Disconnecting 'bla2-PC-01:from_slave_8' from
 'ardour:OBXDLR/audio_in 2'
 10:48:34.615 XRUN callback (13 übersprungen).
 10:48:34.940 Schaubild der JACK-Verbindungen geändert.
 Wed Feb 19 10:48:34 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:34 2020: Connecting 'bla2-PC-01:from_slave_4' to
 'ardour:OBXDLR/audio_in 1'
 Wed Feb 19 10:48:35 2020: NetMaster : missing last data packet from
 'bla2-PC'
 10:48:35.660 Schaubild der JACK-Verbindungen geändert.
 10:48:35.789 Benachrichtigung zum Herunterfahren.
 10:48:35.808 Client deaktiviert.
 10:48:35.811 D-BUS: JACK-Server wurde angehalten
 (org.jackaudio.service aka jackdbus).
 Cannot read socket fd = 25 err = Erfolg
 CheckRes error
 JackSocketClientChannel read fail
 Server is not running
 Server is not running
 Wed Feb 19 10:48:35 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:35 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:35 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:35 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:35 2020: Connecting 'bla2-PC-01:from_slave_5' to
 'ardour:OBXDLR/audio_in 2'
 Wed Feb 19 10:48:35 2020: NetMaster : missing last data packet from
 'bla2-PC'
 Wed Feb 19 10:48:35 2020: ERROR: Segmentation Fault!
 Wed Feb 19 10:48:35 2020: ERROR: info.si_signo = 11
 Wed Feb 19 10:48:35 2020: ERROR: info.si_errno = 0
 Wed Feb 19 10:48:35 2020: ERROR: info.si_code  = 1 (SEGV_MAPERR)
 Wed Feb 19 10:48:35 2020: ERROR: info.si_addr  = 0x7f458dace558
 Wed Feb 19 10:48:35 2020: ERROR: reg[00]       = 0x0000000040800000
 Wed Feb 19 10:48:35 2020: ERROR: reg[01]       = 0x0000000000000000
 Wed Feb 19 10:48:35 2020: ERROR: reg[02]       = 0x0000000000000000
 Wed Feb 19 10:48:35 2020: ERROR: reg[03]       = 0x0000000000000246
 Wed Feb 19 10:48:35 2020: ERROR: reg[04]       = 0x00007f47eb77d704
 Wed Feb 19 10:48:35 2020: ERROR: reg[05]       = 0x00007f47eb03f66f
 Wed Feb 19 10:48:35 2020: ERROR: reg[06]       = 0x00007f47eb03f720
 Wed Feb 19 10:48:35 2020: ERROR: reg[07]       = 0x00007f47eaf3df40
 Wed Feb 19 10:48:35 2020: ERROR: reg[08]       = 0x00007f47d4010b10
 Wed Feb 19 10:48:35 2020: ERROR: reg[09]       = 0x00007f47d400d48c
 Wed Feb 19 10:48:35 2020: ERROR: reg[10]       = 0x00007f47eaf3dc60
 Wed Feb 19 10:48:35 2020: ERROR: reg[11]       = 0x00007f47d400c6c0
 Wed Feb 19 10:48:35 2020: ERROR: reg[12]       = 0xfffffffdb9abd9e8
 Wed Feb 19 10:48:35 2020: ERROR: reg[13]       = 0x00007f458dace558
 Wed Feb 19 10:48:35 2020: ERROR: reg[14]       = 0x0000000000000000
 Wed Feb 19 10:48:35 2020: ERROR: reg[15]       = 0x00007f47eaf3dc40
 Wed Feb 19 10:48:35 2020: ERROR: reg[16]       = 0x00007f47ec18ceab
 Wed Feb 19 10:48:35 2020: ERROR: reg[17]       = 0x0000000000010203
 Wed Feb 19 10:48:35 2020: ERROR: reg[18]       = 0x002b000000000033
 Wed Feb 19 10:48:35 2020: ERROR: reg[19]       = 0x0000000000000004
 Wed Feb 19 10:48:35 2020: ERROR: reg[20]       = 0x000000000000000e
 Wed Feb 19 10:48:35 2020: ERROR: reg[21]       = 0x0000000000005a07
 Wed Feb 19 10:48:35 2020: ERROR: reg[22]       = 0x00007f458dace558
 Wed Feb 19 10:48:35 2020: ERROR: Stack trace:
 Wed Feb 19 10:48:35 2020: ERROR:  1: 0x7f47ec18ceab
 <Jack::NetFloatAudioBuffer::RenderFromNetwork(char*, int, int)+47>
 (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  2: 0x7f47ec18cdad
 <Jack::NetFloatAudioBuffer::RenderFromNetwork(int, int, unsigned
 int)+153> (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  3: 0x7f47ec18fe3f
 <Jack::JackNetInterface::AudioRecv(Jack::_packet_header*,
 Jack::NetAudioBuffer*)+205> (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  4: 0x7f47ec190e37
 <Jack::JackNetMasterInterface::DataRecv()+275>
 (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  5: 0x7f47eb77dbd5
 <(null)+3950500821> (/usr/local/lib/jack/netmanager.so)
 Wed Feb 19 10:48:35 2020: ERROR:  6: 0x7f47eb77d724
 <(null)+3950499620> (/usr/local/lib/jack/netmanager.so)
 Wed Feb 19 10:48:35 2020: ERROR:  7: 0x7f47ec14778f
 <Jack::JackClient::CallProcessCallback()+85>
 (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  8: 0x7f47ec14768a
 <Jack::JackClient::ExecuteThread()+40> (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  9: 0x7f47ec144c87
 <Jack::JackClient::Execute()+85> (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR:  10: 0x7f47ec1670e8
 <Jack::JackPosixThread::ThreadHandler(void*)+252>
 (/usr/local/lib/libjackserver.so.0)
 Wed Feb 19 10:48:35 2020: ERROR: End of stack trace