I have normal ping times for about 5 seconds and then they spike to 100-300ms more than normal for about 5 seconds, and back and forth. Example:
64 bytes from 216.58.192.46: icmp_seq=844 ttl=58 time=5.694 ms
64 bytes from 216.58.192.46: icmp_seq=845 ttl=58 time=5.508 ms
64 bytes from 216.58.192.46: icmp_seq=846 ttl=58 time=6.203 ms
64 bytes from 216.58.192.46: icmp_seq=847 ttl=58 time=6.665 ms
64 bytes from 216.58.192.46: icmp_seq=848 ttl=58 time=6.074 ms
64 bytes from 216.58.192.46: icmp_seq=849 ttl=58 time=7.480 ms
64 bytes from 216.58.192.46: icmp_seq=850 ttl=58 time=54.219 ms
64 bytes from 216.58.192.46: icmp_seq=851 ttl=58 time=101.125 ms
64 bytes from 216.58.192.46: icmp_seq=852 ttl=58 time=144.924 ms
64 bytes from 216.58.192.46: icmp_seq=853 ttl=58 time=188.527 ms
64 bytes from 216.58.192.46: icmp_seq=854 ttl=58 time=5.604 ms
64 bytes from 216.58.192.46: icmp_seq=855 ttl=58 time=5.553 ms
64 bytes from 216.58.192.46: icmp_seq=856 ttl=58 time=9.515 ms
64 bytes from 216.58.192.46: icmp_seq=857 ttl=58 time=5.364 ms
64 bytes from 216.58.192.46: icmp_seq=858 ttl=58 time=16.086 ms
64 bytes from 216.58.192.46: icmp_seq=859 ttl=58 time=8.182 ms
64 bytes from 216.58.192.46: icmp_seq=860 ttl=58 time=28.378 ms
64 bytes from 216.58.192.46: icmp_seq=861 ttl=58 time=27.358 ms
64 bytes from 216.58.192.46: icmp_seq=862 ttl=58 time=73.504 ms
64 bytes from 216.58.192.46: icmp_seq=863 ttl=58 time=119.722 ms
64 bytes from 216.58.192.46: icmp_seq=864 ttl=58 time=174.853 ms
64 bytes from 216.58.192.46: icmp_seq=865 ttl=58 time=210.945 ms
And so on. It does this at home and at work, and plugging into ethernet via thunderbolt does not exhibit these behaviors.
After doing a binary search of killing apps, I have discovered that killing the Boom 2 app causes the spikes to go away, which is strange because I wouldn't figure that an audio enhancement app would have anything to do with the network. It's not sending or receiving bytes according to Activity Monitor, but merely *being active* somehow causes ping times to fluctuate in this manner **only on wifi**. Anybody have an inkling of why this might be the case?
Originally posted here:
https://apple.stackexchange.com/questions/192149/why-do-my-network-ping-times-keep-oscillating-on-wireless 
Comments
It has come to our notice that a few users have been experiencing issues with their Internet connectivity with the latest update of Boom 2. We released v1.2 with a new companion iOS app called ‘Boom 2 Remote’ that can wirelessly control Boom 2 via WiFi. After its release, certain users were facing problems with their Internet speed when using the remote to control Boom 2. Even those who weren’t using the remote but had the ‘Boom Remote’ option turned on under Boom 2’s Settings reported similar issues.
We’re writing to you to apologise for any inconvenience caused and that an update is on its way. We’ve worked directly with Apple and found that this was due to a limitation in the Multipeer framework used. This is the same framework used by ‘AirDrop’ on the Mac & iOS and similar random connectivity issues can be seen even when using AirDrop.
As a temporary fix, please turn OFF the ‘Boom Remote’ option under Boom 2’s settings when not in use. An update will be out soon that takes care of this. Also, you can look forward to new features coming to the Boom 2 Remote (Yes, we’re adding Spotify support too!)