Slow download speed from Denmark and Singapore

We are experiencing very slow and unstable downloads from our main offices in Denmark and Singapore.

Denmark’s has a 900M symmetrical line at the largest ISP TDC and when copying over our VPN or outside FTP to our Denver office where the line is 125/25 we experience slow and erratic speed where copying often goes down to zero or 355Kb/s. The highest speed obtained is 13 M in peaks.
Copying data from US to Denmark however is very high and stable and we can obtain up to 17M in upload!

Also traceroute indicates 11 hops to Denmark but 15 hops back!

Copy files to Singapore is also slow, however stable but never higher than 6.9M. Uploading files to Singapore goes very fast and almost 17M is possible and very stable. Trace routes seems okay..

In both external locations we are testing between powerful win2012R2 server, getting optimal results from the TCP Protocol if possible..

We know the issues with limitations in the TCP protocol, but if lines are stable and without packet loss the protocol can adjust and carry much higher data rates..

Does Comcast have limitations in speed download from other countries?

Route from US to DK:

C:\Users\mom>tracert ap.dk.dhigroup.com

Tracing route to ap.dk.dhigroup.com [193.3.62.135]
over a maximum of 30 hops:

  1     6 ms     5 ms     3 ms  96-81-50-38-static.hfc.comcastbusiness.net [96.81.50.38]
  2    18 ms    16 ms    12 ms  96.120.13.21
  3    55 ms    48 ms    39 ms  xe-9-1-1-sur03.wheatridge.co.denver.comcast.net [162.151.38.1]
  4    14 ms    16 ms    15 ms  ae-30-ar01.denver.co.denver.comcast.net [162.151.51.9]
  5     *        *        *     Request timed out.
  6   139 ms   136 ms   148 ms  ae-229-3605.edge5.paris1.level3.net [4.69.159.50]
  7   143 ms   149 ms   140 ms  colt-teleco.edge5.paris1.level3.net [212.73.200.90]
  8   158 ms   156 ms   159 ms  84.16.161.73
  9   158 ms   169 ms   164 ms  84.16.161.74
 10   166 ms   162 ms   158 ms  dkcph1-fw-remotevpn-outside.dhi.dk [193.3.62.135]

Trace complete.

Route from DK to US - Pls. note the may hops inside Comcast network:

tracert ap.us.dhigroup.com

Tracing route to ap.us.dhigroup.com [96.81.50.33]

over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms  dkcph1-sw200.dhi.dk [10.1.1.1]

  2    <1 ms    <1 ms    <1 ms  dkcph1-colt-pri-int-lan.dhi.dk [193.3.62.129]

  3     5 ms     5 ms     4 ms  fa0-1-ar1.LIS.router.colt.net [212.74.69.209]

  4     9 ms     8 ms     8 ms  te0-2-1-0-pr1.ham.router.colt.net [212.74.81.230]

  5    13 ms    12 ms    12 ms  194.25.209.65

  6   102 ms   101 ms   101 ms  217.239.40.94

  7    98 ms    97 ms    99 ms  80.150.169.198

  8   101 ms   101 ms   100 ms  hu-1-4-0-0-cr02.ashburn.va.ibone.comcast.net [68.86.83.1]

  9   114 ms   116 ms   115 ms  be-10114-cr02.56marietta.ga.ibone.comcast.net [68.86.85.10]

10   132 ms   133 ms   134 ms  be-11424-cr02.dallas.tx.ibone.comcast.net [68.86.85.22]

11   172 ms   174 ms   173 ms  be-11724-cr02.denver.co.ibone.comcast.net [68.86.84.229]

12   143 ms   143 ms   143 ms  ae-79-ar01.aurora.co.denver.comcast.net [68.86.92.130]

13   144 ms   144 ms   144 ms  ae-0-sur02.wheatridge.co.denver.comcast.net [162.151.51.18]

14   144 ms   144 ms   144 ms  te-7-0-acr03.wheatridge.co.denver.comcast.net [162.151.38.6]

15     *        *        *     Request timed out.

16   157 ms   159 ms   156 ms  96-81-50-33-static.hfc.comcastbusiness.net [96.81.50.33]

Trace complete.

Br.

Morten