ECS跟RDS网络传输耗时问题

看到一个关于RDS帖子的疑问，特意ping了下我的RDS，结果如下：

[root@AY130718104911577411Z logs]# ping istk*****.mysql.rds.aliyuncs.com
PING insentek.mysql.rds.aliyuncs.com (115.29.64.57) 56(84) bytes of data.
64 bytes from 115.29.64.57: icmp_seq=1 ttl=61 time=0.309 ms
64 bytes from 115.29.64.57: icmp_seq=2 ttl=61 time=139 ms
64 bytes from 115.29.64.57: icmp_seq=3 ttl=61 time=0.244 ms
64 bytes from 115.29.64.57: icmp_seq=4 ttl=61 time=0.279 ms
64 bytes from 115.29.64.57: icmp_seq=5 ttl=61 time=3.46 ms
64 bytes from 115.29.64.57: icmp_seq=6 ttl=61 time=0.260 ms
64 bytes from 115.29.64.57: icmp_seq=7 ttl=61 time=0.259 ms
64 bytes from 115.29.64.57: icmp_seq=8 ttl=61 time=0.346 ms
64 bytes from 115.29.64.57: icmp_seq=9 ttl=61 time=35.2 ms
64 bytes from 115.29.64.57: icmp_seq=10 ttl=61 time=0.250 ms
64 bytes from 115.29.64.57: icmp_seq=11 ttl=61 time=0.237 ms
64 bytes from 115.29.64.57: icmp_seq=12 ttl=61 time=334 ms
64 bytes from 115.29.64.57: icmp_seq=13 ttl=61 time=33.8 ms
64 bytes from 115.29.64.57: icmp_seq=14 ttl=61 time=0.401 ms
64 bytes from 115.29.64.57: icmp_seq=15 ttl=61 time=0.288 ms
64 bytes from 115.29.64.57: icmp_seq=16 ttl=61 time=19.0 ms
64 bytes from 115.29.64.57: icmp_seq=17 ttl=61 time=0.260 ms
64 bytes from 115.29.64.57: icmp_seq=18 ttl=61 time=0.239 ms
64 bytes from 115.29.64.57: icmp_seq=19 ttl=61 time=37.3 ms
64 bytes from 115.29.64.57: icmp_seq=20 ttl=61 time=0.212 ms
64 bytes from 115.29.64.57: icmp_seq=21 ttl=61 time=0.327 ms
64 bytes from 115.29.64.57: icmp_seq=22 ttl=61 time=0.273 ms
64 bytes from 115.29.64.57: icmp_seq=23 ttl=61 time=0.295 ms
64 bytes from 115.29.64.57: icmp_seq=24 ttl=61 time=0.290 ms
64 bytes from 115.29.64.57: icmp_seq=25 ttl=61 time=262 ms
64 bytes from 115.29.64.57: icmp_seq=26 ttl=61 time=11.1 ms
64 bytes from 115.29.64.57: icmp_seq=27 ttl=61 time=0.259 ms
64 bytes from 115.29.64.57: icmp_seq=28 ttl=61 time=0.254 ms
64 bytes from 115.29.64.57: icmp_seq=29 ttl=61 time=36.7 ms
64 bytes from 115.29.64.57: icmp_seq=30 ttl=61 time=0.256 ms
64 bytes from 115.29.64.57: icmp_seq=31 ttl=61 time=0.305 ms
64 bytes from 115.29.64.57: icmp_seq=32 ttl=61 time=0.277 ms
64 bytes from 115.29.64.57: icmp_seq=33 ttl=61 time=0.340 ms
64 bytes from 115.29.64.57: icmp_seq=34 ttl=61 time=0.255 ms
64 bytes from 115.29.64.57: icmp_seq=35 ttl=61 time=284 ms
64 bytes from 115.29.64.57: icmp_seq=36 ttl=61 time=32.9 ms




求回复，到底怎么回事，会有这么大的波动？？？？