Wenn das Kabelmodem für Telefonie und Internet genutzt wird, ist ziemlich sicher neben der schlechten Telefonie-Sprachqualität auch die Internetverbindung massiv gestört.
Die Qualität der Telefonie-Verbindung kann mit einer IPerf-Messung über die Internetverbindung sehr gut geschätzt werden:
IPerf-Download
30 Sekunden langes Telefongespräch simulieren:
\=> Wichtig: IPerf-Messungen dürfen nicht über WLAN durchgeführt werden!
Abgehende Sprache (Mund)
iperf3 -u -t 30 -O 2 -c debit.k-net.fr -b 64k -l 160
Ankommende Sprache (Ohr)
iperf3 -u -R -t 30 -O 2 -c debit.k-net.fr -b 64k -l 160
Als Faustregel für gute VoIP-Sprachqualität gilt:
< 1 % Paketverluste (Lost Datagrams)
< 30 Millisekunden Jitter
< 150 Millisekunden Einweglaufzeit von Mund zu Ohr
Hinweis: Sprachtelefonie bei UPC Cablecom ist VoIP (SIP/RTP) mit dem Audiocodec G.711 (64 kbit/s, 20 ms Audiosample).
Die Einweglaufzeit kann nicht mit IPerf gemessen werden. Ping misst die Laufzeit für beide Wege (hin und zurück = 2x Einweglaufzeit).
Beispiel Abgehende Sprache (Mund):
# iperf3 -u -t 30 -O 2 -c debit.k-net.fr -b 64k -l 160
Connecting to host debit.k-net.fr, port 5201
[ 4] local 192.168.3.40 port 34393 connected to 178.250.209.22 port 5201
[ ID] Interval Transfer Bandwidth Total Datagrams
[ 4] 0.00-1.00 sec 7.19 KBytes 58.9 Kbits/sec 46 (omitted)
[ 4] 1.00-2.00 sec 7.81 KBytes 64.0 Kbits/sec 50 (omitted)
[ 4] 0.00-1.00 sec 7.19 KBytes 58.9 Kbits/sec 46
[ 4] 1.00-2.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 2.00-3.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 3.00-4.00 sec 7.97 KBytes 65.3 Kbits/sec 51
[ 4] 4.00-5.00 sec 7.66 KBytes 62.7 Kbits/sec 49
[ 4] 5.00-6.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 6.00-7.00 sec 7.97 KBytes 65.3 Kbits/sec 51
[ 4] 7.00-8.00 sec 7.66 KBytes 62.7 Kbits/sec 49
[ 4] 8.00-9.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 9.00-10.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 10.00-11.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 11.00-12.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 12.00-13.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 13.00-14.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 14.00-15.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 15.00-16.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 16.00-17.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 17.00-18.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 18.00-19.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 19.00-20.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 20.00-21.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 21.00-22.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 22.00-23.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 23.00-24.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 24.00-25.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 25.00-26.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 26.00-27.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ 4] 27.00-28.00 sec 7.97 KBytes 65.3 Kbits/sec 51
[ 4] 28.00-29.00 sec 7.66 KBytes 62.7 Kbits/sec 49
[ 4] 29.00-30.00 sec 7.81 KBytes 64.0 Kbits/sec 50
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 4] 0.00-30.00 sec 234 KBytes 63.8 Kbits/sec 1.418 ms 1/1496 (0.067%)
[ 4] Sent 1496 datagrams
iperf Done.
Beispiel Ankommende Sprache (Ohr):
# iperf3 -u -R -t 30 -O 2 -c debit.k-net.fr -b 64k -l 160
Connecting to host debit.k-net.fr, port 5201
Reverse mode, remote host debit.k-net.fr is sending
[ 4] local 192.168.3.40 port 53708 connected to 178.250.209.22 port 5201
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 4] 0.00-1.00 sec 7.97 KBytes 65.3 Kbits/sec 650.837 ms 0/51 (0%) (omitted)
[ 4] 1.00-2.00 sec 7.19 KBytes 58.9 Kbits/sec 34.076 ms 0/46 (0%) (omitted)
[ 4] 0.00-1.00 sec 7.66 KBytes 62.7 Kbits/sec 0.747 ms 0/49 (0%)
[ 4] 1.00-2.00 sec 7.81 KBytes 64.0 Kbits/sec 0.470 ms 0/50 (0%)
[ 4] 2.00-3.00 sec 7.97 KBytes 65.3 Kbits/sec 0.506 ms 0/51 (0%)
[ 4] 3.00-4.00 sec 7.81 KBytes 64.0 Kbits/sec 0.239 ms 0/50 (0%)
[ 4] 4.00-5.00 sec 7.81 KBytes 64.0 Kbits/sec 0.412 ms 0/50 (0%)
[ 4] 5.00-6.00 sec 7.81 KBytes 64.0 Kbits/sec 0.523 ms 0/50 (0%)
[ 4] 6.00-7.00 sec 7.81 KBytes 64.0 Kbits/sec 0.279 ms 0/50 (0%)
[ 4] 7.00-8.00 sec 7.81 KBytes 64.0 Kbits/sec 0.529 ms 0/50 (0%)
[ 4] 8.00-9.00 sec 7.81 KBytes 64.0 Kbits/sec 0.347 ms 0/50 (0%)
[ 4] 9.00-10.00 sec 7.03 KBytes 57.6 Kbits/sec 0.218 ms 5/50 (10%)
[ 4] 10.00-11.00 sec 7.81 KBytes 64.0 Kbits/sec 0.472 ms 0/50 (0%)
[ 4] 11.00-12.00 sec 7.81 KBytes 64.0 Kbits/sec 0.621 ms 0/50 (0%)
[ 4] 12.00-13.00 sec 7.81 KBytes 64.0 Kbits/sec 0.693 ms 0/50 (0%)
[ 4] 13.00-14.00 sec 7.81 KBytes 64.0 Kbits/sec 0.232 ms 0/50 (0%)
[ 4] 14.00-15.00 sec 7.81 KBytes 64.0 Kbits/sec 0.455 ms 0/50 (0%)
[ 4] 15.00-16.00 sec 7.81 KBytes 64.0 Kbits/sec 0.394 ms 0/50 (0%)
[ 4] 16.00-17.00 sec 7.81 KBytes 64.0 Kbits/sec 0.430 ms 0/50 (0%)
[ 4] 17.00-18.00 sec 7.81 KBytes 64.0 Kbits/sec 0.603 ms 0/50 (0%)
[ 4] 18.00-19.00 sec 7.66 KBytes 62.7 Kbits/sec 0.449 ms 0/49 (0%)
[ 4] 19.00-20.00 sec 7.97 KBytes 65.3 Kbits/sec 0.446 ms 0/51 (0%)
[ 4] 20.00-21.00 sec 7.81 KBytes 64.0 Kbits/sec 0.133 ms 0/50 (0%)
[ 4] 21.00-22.00 sec 7.81 KBytes 64.0 Kbits/sec 0.140 ms 0/50 (0%)
[ 4] 22.00-23.00 sec 7.81 KBytes 64.0 Kbits/sec 0.503 ms 0/50 (0%)
[ 4] 23.00-24.00 sec 7.81 KBytes 64.0 Kbits/sec 0.218 ms 0/50 (0%)
[ 4] 24.00-25.00 sec 7.81 KBytes 64.0 Kbits/sec 0.575 ms 0/50 (0%)
[ 4] 25.00-26.00 sec 7.81 KBytes 64.0 Kbits/sec 0.638 ms 0/50 (0%)
[ 4] 26.00-27.00 sec 7.81 KBytes 64.0 Kbits/sec 0.636 ms 0/50 (0%)
[ 4] 27.00-28.00 sec 7.50 KBytes 61.4 Kbits/sec 0.698 ms 0/48 (0%)
[ 4] 28.00-29.00 sec 7.81 KBytes 64.0 Kbits/sec 0.581 ms 2/52 (3.8%)
[ 4] 29.00-30.00 sec 7.66 KBytes 62.7 Kbits/sec 0.481 ms 1/50 (2%)
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 4] 0.00-30.00 sec 235 KBytes 64.0 Kbits/sec 0.481 ms 8/1500 (0.53%)
[ 4] Sent 1500 datagrams
iperf Done.