Saturated Network?

Discussion created by audacity on Sep 21, 2013
Latest reply on Oct 15, 2013 by [shaw]heather

Quick Summary: I believe the Shaw network is completely saturated in my area in the evenings.  I'm posting here because I think I can articulate the problem (and the evidence I have) better on a forum than talking to someone on the phone.  All the tests run here are over wired gigabit Ethernet.  No wireless.


Lets start with a run. by Ookla - My Results


So, on a BB100 connection I'm seeing 4.79 megabit/s up (which is fine), and 8.45 megabit/s down (not fine).  I've run a number of test and this one is pretty typical.  I'm not cherry-picking the worst test that I ran during this time period, this is right around the average reading tonight when trying a number of different servers.


Since having some network quality issues with Shaw over a year ago, I've been running network monitoring software to help me diagnose the root cause of issues when they come up.


The first sensor I have is tracking the ping time between a device on my local LAN and Shaw's network gateway, which for me is  Every minute it sends 20 ICMP packets, and records the results.  The general expectation here would be that the ping times for the first network hop would be less than 10ms.  Perhaps 20ms at the most.  What am I seeing?  I'm getting the occasional ping back over 1000ms, and many pings over 100ms.  That's up to two orders of magnitude worse than what I should expect for my network gateway.  See attached file "Ping Gateway.png", note the counters between 8:55pm and 9:20pm.


The natural reaction may be to say "well, perhaps someone on your network was using a tonne of bandwidth, saturating your connection".  Yup, that could certainly be it.  Look at the attached file "Bandwidth Use.png", which charts the bandwidth used during the same time period.  You'll notice that yes, someone was watching a streaming video at the time when the network latency became intolerable (I was playing a online game at the time), but note that the amount of bandwidth used by the streaming video between 8:55pm and 9:20pm was using between 1 and 2 megabit/s.  That's almost nothing for a Internet connection that is supposed to be able to support 100 megabit/s.


I should note that most of the time this isn't a issue.  When it's not in the middle of the evening test bring back between 80mbps and 100mbps, and I can have a couple Netflix movies on the go and still get great ping times.  So that eliminates the problem being my router/switch, because it was a configuration issue or the router or modem needing a reboot, it wouldn't magically get better in the middle of the night.


Now, one might say "well, you're just making a mountain out of a single network event".  Well, that's the problem - this isn't just a one time thing.  I've been having this issue every evening for a long time now.  See the chart "Ping Gateway (last 30 days).png".  You'll see that I'm getting pings in the hundreds of milliseconds on a regular basis every night.  100ms might not seem like a long time, but that's actually pretty terrible when it's normally ~8ms, and that's the lowest ping I would ever get on the internet since all the packets sent/received would go through that gateway.


I fancy myself a bit of a expert when it comes to IP networking.  I'll put my expert hat on for a second and say that you normally should only get a significant increase in latency when your network is saturated.  Now, my problem is that if I'm getting the symptoms of a saturated network when I'm using less than 2mbps of bandwidth we have a big problem.  Or at least I have a big problem if I want to be able to play online games in the evening.  It's difficult to win games when your ping sucks.  Having the low numbers during the problem times is additional evidence that Shaw's network is saturated.