Latency spikes every 5 minutes on my wireless network

When I first created pingcatcher and began monitoring my own network I noticed a strange phenomenon. Every 5 minutes, almost to the second, my latency would spike.

Notice how these latency spikes were to my wireless router so it immediately removed my ISP from the equation. Something was happening on my wirless network and I suspected my wireless router or some other device interferring with the signal on a 5 minute schedule. My first thought was to remove the wireless network from the equation. I plugged in an Ethernet cable and saw the latency spikes disappear.

Very nice! It’s unlikely to be the router. There’s something very strange happening on my wireless network.

The next troubleshooting step I took was to connect to my phone’s hotspot. Let’s see if I’m able to reproduce the issue on a separate wireless network and remove my router from the equation completely. Here’s what latency looked like on my hotspot. Same 5m spikes in latency.

At this point I thought it must be my apartment. There’s something interfering with my wireless signal. I decided to go into my local Starbucks and run the same test. Here’s what my latency looked like at Starbucks:

Holy cow. It was happening at Starbucks as well. Since it’s an entirely different network and location - there’s only one possible explanation: there’s something on my machine causing these spikes.

Out of curiousity, I decided to look at Mac OS logs for hints. Perhaps on the 5m mark, I’d see something interesting.

Mac Os logging is quite verbose, here’s what it looks like when you first start it up.

And here’s what I saw in Mac OS logger just as another latency spike occurred.

~$ traceroute 8.8.8.8 2>&1 | head -2 | tail -1
 1  router (192.168.3.1)  1.793 ms  1.707 ms  3.030 ms

Unbelievable. Mac OS Location Services is disconnecting me from my WiFi network to look for near-by wireless networks. It’s doing this every 5 minutes. What in the world? What exactly were Apple engineers thinking? That no-one would notice? This was a pretty horrifying discovery. What else is my machine doing on (and off) the network that I’m not aware of.

Here’s how you can disable Location Services on Mac OS.

After disabling Location Services, here’s what happened to my network latency:

No more latency spikes. Completely insane. If this helped you, Sign Up below for a free account. We’ll let you know when we publish new useful tidbits on network performance!