High ping latency with iOS devices (iPad / iPhone)ping
ing my iPad / iPhone shows an unreasonable high latency even if there’s no load on WiFi:
123456 # ping 1.1.1.2PING 1.1.1.2 (1.1.1.2) 56(84) bytes of data.64 bytes from 1.1.1.2: icmp_seq=1 ttl=64 time=15.7 ms64 bytes from 1.1.1.2: icmp_seq=2 ttl=64 time=42.0 ms64 bytes from 1.1.1.2: icmp_seq=3 ttl=64 time=65.2 ms64 bytes from 1.1.1.2: icmp_seq=4 ttl=64 time=89.4 ms
… while ping
ing my other devices from the iPad does show a lower latency (less than 10ms).
But then I discovered that the latency drops when I run speedtest on the iPad:
123456 # ping 1.1.1.2PING 1.1.1.2 (1.1.1.2) 56(84) bytes of data.64 bytes from 1.1.1.2: icmp_seq=48 ttl=64 time=3.44 ms64 bytes from 1.1.1.2: icmp_seq=49 ttl=64 time=2.48 ms64 bytes from 1.1.1.2: icmp_seq=50 ttl=64 time=2.08 ms64 bytes from 1.1.1.2: icmp_seq=51 ttl=64 time=3.20 ms
So I assume it’s related to some energy saving policies. Perhaps by scanning for (/receiving) signals less frequently the device could save the battery’s life. But once there’s some work to do, the device automatically disables the energy saving policy and runs on full speed.
ping
ing my iPad / iPhone shows an unreasonable high latency even if there’s no load on WiFi:
1 2 3 4 5 6 | # ping 1.1.1.2 PING 1.1.1.2 (1.1.1.2) 56(84) bytes of data. 64 bytes from 1.1.1.2: icmp_seq=1 ttl=64 time=15.7 ms 64 bytes from 1.1.1.2: icmp_seq=2 ttl=64 time=42.0 ms 64 bytes from 1.1.1.2: icmp_seq=3 ttl=64 time=65.2 ms 64 bytes from 1.1.1.2: icmp_seq=4 ttl=64 time=89.4 ms |
… while ping
ing my other devices from the iPad does show a lower latency (less than 10ms).
But then I discovered that the latency drops when I run speedtest on the iPad:
1 2 3 4 5 6 | # ping 1.1.1.2 PING 1.1.1.2 (1.1.1.2) 56(84) bytes of data. 64 bytes from 1.1.1.2: icmp_seq=48 ttl=64 time=3.44 ms 64 bytes from 1.1.1.2: icmp_seq=49 ttl=64 time=2.48 ms 64 bytes from 1.1.1.2: icmp_seq=50 ttl=64 time=2.08 ms 64 bytes from 1.1.1.2: icmp_seq=51 ttl=64 time=3.20 ms |
So I assume it’s related to some energy saving policies. Perhaps by scanning for (/receiving) signals less frequently the device could save the battery’s life. But once there’s some work to do, the device automatically disables the energy saving policy and runs on full speed.