```json
{
    "title": "GrabPERF: Think you have Packet Loss? This is what it looks like",
    "url": "https://performancezen.com/2005/10/06/grabperf-think-you-have-packet-loss-this-is-what-it-looks-like/",
    "datePublished": "2005-10-06",
    "dateModified": "2005-10-06",
    "language": "en-US",
    "description": "So, I mentioned earlier that I have packet loss on the uplink from my Web server where GrabPERF and this blog are hosted. How do I know it's packet loss…",
    "author": "spierzchala",
    "publisher": "Performance Zen"
}
```

# GrabPERF: Think you have Packet Loss? This is what it looks like

So, I mentioned earlier that I have packet loss on the uplink from my Web server where [GrabPERF](http://www.grabperf.org/) and this blog are hosted. How do I know it's packet loss and not some other issue?
[http://www.newestindustry.org/media/newest_industry_packet-loss-oct062005.png](http://www.newestindustry.org/media/newest_industry_packet-loss-oct062005.png)
**CLICK THE IMAGE**
Notice the banding of measurements around 3 and 9 seconds? These values are the set TCP re-transmission timeouts for new connections for almost every operating system. When you see this pattern, check your packet loss stats from your routers/switches/network equipment.
Now...I wonder what [my connectivity provider](http://www.comcast.com/) has mucked up?