Game latency increases during day, not shown in ping command

Question

Command-line ping command shows 81ms to eu.newerth.com server 24/7. However for the last few days my in-game ping is 135 during the day, and 95 during the night (correlates with times of low server activity.)

It's normal to have about 15ms extra ingame (as I do at night), but the jump during the day is puzzling because it doesn't translate in the icmp ping measure.

The game itself uses UDP, although I think the game measures ping with TCP.

I'm in USA on a very fast university ISP and the server is in London, the problem seems to be affecting other american clients but I'm not sure. It is not affecting players from Europe.

My in-game latency to other servers in the same game, for example one in Germany, do not experience the same night/day cycle and are staying stable.

What could be the cause of the in-game increase without corresponding icmp increase?

Answer 1

Diagnosis:

First do a Tracert to eu.newerth.com.

Traceroute is a computer network tool used to determine the route taken by packets across an IP network.

Here is the output from my computer (first few hops removed):

Tracing route to eu.newerth.com [87.117.228.107]
over a maximum of 30 hops:

[snip]

  4    46 ms    70 ms    21 ms  asd-tr0610-cr101-ae6-0.core.as9143.net [213.51.158.82]
  5    88 ms    78 ms    83 ms  ae5-125.ams29.ip4.gtt.net [77.67.64.65]
  6    28 ms    36 ms    37 ms  xe-7-2-1.lon25.ip4.gtt.net [141.136.107.38]
  7   139 ms   125 ms    58 ms  iomart-gw.ip4.gtt.net [46.33.94.2]
  8    73 ms    87 ms    75 ms  610.net2.north.dc5.as20860.net [62.233.127.182]
  9    67 ms    71 ms    28 ms  87.117.212.42
 10    48 ms    27 ms    21 ms  eu.newerth.com [87.117.228.107]

We can see from this that there is an issue with hop 7 as two of the 3 round trip times are higher than expected compared to the hops either side. This can indicate network congestion or an overloaded router:

  7   139 ms   125 ms    58 ms  iomart-gw.ip4.gtt.net [46.33.94.2]

Now try a PathPing to eu.newerth.com.

Pathping is a TCP/IP based utility (command-line tool) that provides useful information about network Latency and Packet Loss at intermediate hops between a source address and a destination address.

It does this by sending "echo request" packets via ICMP and analyzing the results.

Here is the output from my computer (first few hops removed):

Tracing route to eu.newerth.com [87.117.228.107]
over a maximum of 30 hops:

[snip]

  3  hlo-lc0001-cr102-ae10-218.core.as9143.net [213.51.166.82]
  4  asd-tr0610-cr101-ae6-0.core.as9143.net [213.51.158.82]
  5  ae5-125.ams29.ip4.gtt.net [77.67.64.65]
  6  xe-7-2-1.lon25.ip4.gtt.net [141.136.107.38]
  7  iomart-gw.ip4.gtt.net [46.33.94.2]
  8  610.net2.north.dc5.as20860.net [62.233.127.182]
  9  87.117.212.42
 10  eu.newerth.com [87.117.228.107]

Computing statistics for 250 seconds...
            Source to Here   This Node/Link
Hop  RTT    Lost/Sent = Pct  Lost/Sent = Pct  Address

[snip]

                                0/ 100 =  0%   |
  3   46ms     0/ 100 =  0%     0/ 100 =  0%  hlo-lc0001-cr102-ae10-218.core.as9143.net [213.51.166.82]
                                0/ 100 =  0%   |
  4   53ms     0/ 100 =  0%     0/ 100 =  0%  asd-tr0610-cr101-ae6-0.core.as9143.net [213.51.158.82]
                                0/ 100 =  0%   |
  5   39ms     0/ 100 =  0%     0/ 100 =  0%  ae5-125.ams29.ip4.gtt.net [77.67.64.65]
                                0/ 100 =  0%   |
  6   60ms     0/ 100 =  0%     0/ 100 =  0%  xe-7-2-1.lon25.ip4.gtt.net [141.136.107.38]
                                0/ 100 =  0%   |
  7   73ms     0/ 100 =  0%     0/ 100 =  0%  iomart-gw.ip4.gtt.net [46.33.94.2]
                                0/ 100 =  0%   |
  8   56ms     1/ 100 =  1%     1/ 100 =  1%  610.net2.north.dc5.as20860.net [62.233.127.182]
                                0/ 100 =  0%   |
  9   56ms     1/ 100 =  1%     1/ 100 =  1%  87.117.212.42
                                0/ 100 =  0%   |
 10   50ms     0/ 100 =  0%     0/ 100 =  0%  eu.newerth.com [87.117.228.107]

Trace complete.

We can see from this that there is an issue with hops 8 and 9 as there are 1% packet loss on these hops, but no loss of forwarded packets. This means that the routers at hop8 and 9 are probably a little overloaded:

  8   56ms     1/ 100 =  1%     1/ 100 =  1%  610.net2.north.dc5.as20860.net [62.233.127.182]
                                0/ 100 =  0%   |
  9   56ms     1/ 100 =  1%     1/ 100 =  1%  87.117.212.42

You say "It is not affecting players from Europe". I am in Europe (NL). Judging from the above analysis I would expect to see the same issue as you if I played this game as would other European users using the London server.

The last three hops all belong to iomart.com (a cloud hosting company) so any issue would seem to be inside their infrastructure.

Conclusion:

The routers at 62.233.127.182 and 87.117.212.42 are probably a little overloaded (insufficient capacity for the actual traffic).

Caveat:

This is a snapshot analysis. It also does not take into account the Reverse Route:

Any connection over the Internet actually depends on two routes: the route from the source to the target, and the route from the target back to the source.

• These routes may be (and often are) completely different ("Asymmetric").
• If they differ, a problem in the connection could be a problem with either the route to the target, or with the route back from the target.
• A problem reflected in the Pathping output may actually not lie with the obvious system in the trace; it may rather be with some other system on the reverse route back from the system that looks, from the trace, to be the cause of the problem.
• The reverse path itself is completely invisible in the normal Pathping output!.

A Loose Source Route can be used to see the reverse route. Unfortunately, source routing has a great potential for abuse, and therefore most network administrators block all source-routed packets at their border Routers. So, in practice, loose source routes aren't going to work.

So in order to troubleshoot the reverse route a pathping would have to be done from the game server back to your public IP address.