在DOS命令狀態下輸入 ：
ping 202.105.135.211 -t (連續的對該IP地址執行Ping命令，直到被用戶以Ctrl+C中斷)
就會得到下面的結果：
Pinging 202.105.135.211 with 32 bytes of data:
Reply from 202.105.135.211: bytes=32 time=93ms TTL=42
Reply from 202.105.135.211: bytes=32 time=86ms TTL=42
Reply from 202.105.135.211: bytes=32 time=81ms TTL=42
Reply from 202.105.135.211: bytes=32 time=80ms TTL=42
Ping statistics for 202.105.135.211:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 80ms, Maximum = 93ms, Average = 85ms
這里面，丟包率0%,抖動是-5ms到+8ms，延時是 85ms（毫秒），測試另外兩個IP地址，可以看到：
Pinging 221.221.23.7 with 32 bytes of data:
Reply from 221.221.23.7: bytes=32 time=28ms TTL=48
Reply from 221.221.23.7: bytes=32 time=26ms TTL=48
Reply from 221.221.23.7: bytes=32 time=26ms TTL=48
Reply from 221.221.23.7: bytes=32 time=26ms TTL=48
Reply from 221.221.23.7: bytes=32 time=28ms TTL=48
Reply from 221.221.23.7: bytes=32 time=28ms TTL=48
Reply from 221.221.23.7: bytes=32 time=27ms TTL=48
Reply from 221.221.23.7: bytes=32 time=60ms TTL=48
Reply from 221.221.23.7: bytes=32 time=113ms TTL=48
Reply from 221.221.23.7: bytes=32 time=27ms TTL=48
Reply from 221.221.23.7: bytes=32 time=52ms TTL=48
Reply from 221.221.23.7: bytes=32 time=58ms TTL=48
Reply from 221.221.23.7: bytes=32 time=27ms TTL=48
Reply from 221.221.23.7: bytes=32 time=112ms TTL=48
Reply from 221.221.23.7: bytes=32 time=76ms TTL=48
Reply from 221.221.23.7: bytes=32 time=154ms TTL=48
Ping statistics for 221.221.23.7:
Packets: Sent = 16, Received = 16, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 26ms, Maximum = 154ms, Average = 54ms
丟包率0%,抖動是-28ms到+100ms，延時是 54ms（毫秒）Pinging 221.221.23.209 with 32 bytes of data:
Reply from 221.221.23.209: bytes=32 time=885ms TTL=48
Reply from 221.221.23.209: bytes=32 time=688ms TTL=48
Reply from 221.221.23.209: bytes=32 time=482ms TTL=48
Reply from 221.221.23.209: bytes=32 time=119ms TTL=48
Reply from 221.221.23.209: bytes=32 time=61ms TTL=48
Reply from 221.221.23.209: bytes=32 time=456ms TTL=48
Reply from 221.221.23.209: bytes=32 time=962ms TTL=48
Reply from 221.221.23.209: bytes=32 time=890ms TTL=48
Reply from 221.221.23.209: bytes=32 time=939ms TTL=48
Reply from 221.221.23.209: bytes=32 time=891ms TTL=48
Reply from 221.221.23.209: bytes=32 time=141ms TTL=48
Reply from 221.221.23.209: bytes=32 time=420ms TTL=48
Reply from 221.221.23.209: bytes=32 time=517ms TTL=48
Reply from 221.221.23.209: bytes=32 time=463ms TTL=48
Reply from 221.221.23.209: bytes=32 time=798ms TTL=48
Reply from 221.221.23.209: bytes=32 time=451ms TTL=48
Reply from 221.221.23.209: bytes=32 time=604ms TTL=48
Ping statistics for 221.221.23.209:
Packets: Sent = 17, Received = 17, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 61ms, Maximum = 962ms, Average = 574ms
丟包率0%,抖動是-511ms到+488ms，延時是 574ms（毫秒）
從上面3個結果看，第一組延時小，第三組延時大。丟包率為0％，只有第一組的網絡可以正常使用安裝網絡電話或視頻等保證通話質量，第二組抖動大不可用，第三組延時、抖動都大，也不可用。
根據經驗，這3個指標中，任何一個超標，都不可以安裝用戶端，否則通話質量就沒有保障：
丟包率：小於8％
延時：小於200ms
抖動：正負不大於40ms
安裝網絡電話時，嚴格把住這些基本指標。用戶網絡不能達到這些指標，安裝以后必然出現話音不好的問題。不達標的IP網絡，建議不要安裝，等用戶網絡達標以后再安裝，否則給用戶和代理商帶來許多麻煩。