[LibreQoS] [Starlink] [Rpm] [EXTERNAL] Re: Researchers Seeking Probe Volunteers in USA

[rjmcmahon]

> 	[SM] not really, given enough capacity, typical streaming protocols
> will actually not hit the ceiling, at least the one's I look at every
> now and then tend to stay well below actual capacity of the link.
> 
I think DASH type protocol will hit link peaks. An example with iperf 
2's burst option a controlled WiFi test rig, server side first.


[root at ctrl1fc35 ~]# iperf -s -i 1 -e --histograms
------------------------------------------------------------
Server listening on TCP port 5001 with pid 23764
Read buffer size:  128 KByte (Dist bin width=16.0 KByte)
Enabled receive histograms bin-width=0.100 ms, bins=10000 (clients 
should use --trip-times)
TCP window size:  128 KByte (default)
------------------------------------------------------------
[  1] local 192.168.1.15%enp2s0 port 5001 connected with 192.168.1.234 
port 34894 (burst-period=1.00s) (trip-times) (sock=4) (peer 2.1.9-rc2) 
(icwnd/mss/irtt=14/1448/5170) on 2023-03-13 11:37:24.500 (PDT)
[ ID] Burst (start-end)  Transfer     Bandwidth       XferTime  (DC%)    
  Reads=Dist          NetPwr
[  1] 0.00-0.13 sec  10.0 MBytes   633 Mbits/sec  132.541 ms (13%)    
209=29:31:31:88:11:2:1:16  597
[  1] 1.00-1.11 sec  10.0 MBytes   755 Mbits/sec  111.109 ms (11%)    
205=34:30:22:83:11:2:6:17  849
[  1] 2.00-2.12 sec  10.0 MBytes   716 Mbits/sec  117.196 ms (12%)    
208=33:39:20:81:13:1:5:16  763
[  1] 3.00-3.11 sec  10.0 MBytes   745 Mbits/sec  112.564 ms (11%)    
203=27:36:30:76:6:3:6:19  828
[  1] 4.00-4.11 sec  10.0 MBytes   787 Mbits/sec  106.621 ms (11%)    
193=29:26:19:80:10:4:6:19  922
[  1] 5.00-5.11 sec  10.0 MBytes   769 Mbits/sec  109.148 ms (11%)    
208=36:25:32:86:6:1:5:17  880
[  1] 6.00-6.11 sec  10.0 MBytes   760 Mbits/sec  110.403 ms (11%)    
206=42:30:22:73:8:3:5:23  860
[  1] 7.00-7.11 sec  10.0 MBytes   775 Mbits/sec  108.261 ms (11%)    
171=20:21:21:58:12:1:11:27  895
[  1] 8.00-8.11 sec  10.0 MBytes   746 Mbits/sec  112.405 ms (11%)    
203=36:31:28:70:9:3:2:24  830
[  1] 9.00-9.11 sec  10.0 MBytes   748 Mbits/sec  112.133 ms (11%)    
228=41:56:27:73:7:2:3:19  834
[  1] 0.00-10.00 sec   100 MBytes  83.9 Mbits/sec  
113.238/106.621/132.541/7.367 ms  2034=327:325:252:768:93:22:50:197
[  1] 0.00-10.00 sec F8(f)-PDF: 
bin(w=100us):cnt(10)=1067:1,1083:1,1092:1,1105:1,1112:1,1122:1,1125:1,1126:1,1172:1,1326:1 
(5.00/95.00/99.7%=1067/1326/1326,Outliers=0,obl/obu=0/0) (132.541 
ms/1678732644.500333)


[root at fedora ~]# iperf -c 192.168.1.15 -i 1 -t 10 --burst-size 10M 
--burst-period 1 --trip-times
------------------------------------------------------------
Client connecting to 192.168.1.15, TCP port 5001 with pid 132332 (1 
flows)
Write buffer size: 131072 Byte
Bursting: 10.0 MByte every 1.00 second(s)
TOS set to 0x0 (Nagle on)
TCP window size: 16.0 KByte (default)
Event based writes (pending queue watermark at 16384 bytes)
------------------------------------------------------------
[  1] local 192.168.1.234%eth1 port 34894 connected with 192.168.1.15 
port 5001 (prefetch=16384) (trip-times) (sock=3) 
(icwnd/mss/irtt=14/1448/5489) (ct=5.58 ms) on 2023-03-13 11:37:24.494 
(PDT)
[ ID] Interval        Transfer    Bandwidth       Write/Err  Rtry     
Cwnd/RTT(var)        NetPwr
[  1] 0.00-1.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5517K/18027(1151) us  582
[  1] 1.00-2.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5584K/13003(2383) us  806
[  1] 2.00-3.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5613K/16462(962) us  637
[  1] 3.00-4.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5635K/19523(671) us  537
[  1] 4.00-5.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5594K/10013(1685) us  1047
[  1] 5.00-6.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5479K/14008(654) us  749
[  1] 6.00-7.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5613K/17752(283) us  591
[  1] 7.00-8.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5599K/17743(436) us  591
[  1] 8.00-9.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
5577K/11214(2538) us  935
[  1] 9.00-10.00 sec  10.0 MBytes  83.9 Mbits/sec  80/0         0     
4178K/7251(993) us  1446
[  1] 0.00-10.01 sec   100 MBytes  83.8 Mbits/sec  800/0         0     
4178K/7725(1694) us  1356
[root at fedora ~]#

Note: Client side output is being updated to support outputs based upon 
the bursts. This allows one to see that a DASH type protocol can drive 
the bw bottleneck queue.

Bob