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ptseng's profile

New Member


2 Messages

Tue, Feb 25, 2014 10:00 AM

VPN speed issues



I am a Comcast Business user with a 50/10 connection in Charlottesville, Virginia.


My needs are simple - I work in a local university hospital, and sometimes need to connect from home overnight or on weekends for urgent patient cases.  So when I'm not using the connection as a home internet connection, I primarily connect to a VPN with a Citrix server, which hosts some proprietary software that displays certain patient data and relevant video.  Video is vital to what I do, so I require reasonable speed.


At certain times of the day I've managed to get 15mbit/s down, and video runs at a decent speed.  At peak times, however, I rarely see speeds upward of 700kbit/s down from the VPN, and the video is so slow as to be unusable, I might as well hop in my car and drive to work.


I don't know that I'm checking the appropriate servers, but I ran a tracert to from my work computer.  I see 9 hops within the intranet, and 6 hops through different Cogent servers, then finally multiple Comcast servers across the country.  Granted, I'm aware that (1) my work computer is not the Citrix server, and (2) probably isn't the correct server to be pinging.  Nevertheless, I think my questions are as follows:


  1. How can I fix this?
  2. How can I fix this?
  3. How can I fix this?

Just kidding...


  1. How can I locate the bottleneck? If I run speedtests on my comcast connection when the VPN connection is crazy slow, I'm still getting 50/10 down/up. The rest of the Internet seems to be working just fine, as well.
  2. Supposing I can locate the bottleneck and it's distant from my Comcast connection, what are my options to fix the problem?  What if it's at the university site?  What if it's somewhere in between?

Any suggestions or information would be greatly appreciated.  I have tried our local IT contacts, but they have been of limited assistance (of the "unplug and reboot your computer" variety).





Accepted Solution

Problem solver


305 Messages

8 y ago

The first thing you'll want to test is if the VPN is the cause of your slow connection. It's very common for speeds to dimish during peak times, but VPN's also aren't really meant for speed.


So try this. Next time you started seeing slow speeds disconnect from the VPN and test your comcast connection. Ping a few sites, run some speed test and average the results. 


Now hop on the VPN and do the same thing. If you notice the VPN is causing the slow-down it is likely Comcast isn't directly responsible. 


Another thing to note is, where is this Citrix server? While your work may be close, this server could be across the country, and on a VPN that's horrible. 


It's also very possible that Citrix is the root cause of the slow down.

Accepted Solution



1.4K Messages

8 y ago

Hello ptseng,


I believe kraze user hit most of the nails on the head wrt to his post. I have very , very large inter-location network experience and can provide the following inputs for you to consider:

1. It sound to me that your Centrix server needs some much higher speed for inter-location access. I am referring to the Comcast Metro ENET ( Check this out ) " Comcast Business Ethernet Network Services can seamlessly network you with 10Mbps, 100Mbps, 1Gbps or 10Gbps Ethernet User-to-Network Interfaces (UNI) that are Certified MEF Compliant. - See more at: ."


So, it woould look something like this :

Something Like This.....


There are many Comcast Enterprise Customers who use this to ensure their communication facilities and the

Density of their Data Transport Requirements (DDTR) are met. You mentiioned in your post that your DDTR have video file format to deal with and this is one of the highest density file formats there is.


Even though you are using 50 Mbps down / 10 Mbps up, this is only actually  6.25 MegaBytesPerSecond down and 1.25 MegBytesPerSecond up, which considering your DDTR is not much. So, if you use a 10Gbps ENET connection this is really a 1.25 GigaBytesPerSecond data speed increase, which is a bunch. Lastly, there are very highly specialized Enet routers used for this type of Metro Internet access, too, that use very specialized and very fast ciruit packet switching protocol over Enet.


Hope this helps you and your IT folks out.  





New Member


2 Messages

8 y ago

I appreciate the suggestions! It didn't occur to me to try running speedtests while the VPN was connected. Lo and behold, the connection drops from 50/10 to at best 5.5/8, and I tried polling a few different servers.  5.5 mbit/s during peak times on the VPN seems to correspond pretty well to the 700kbyte/sec I was seeing...


I am at a fairly large university, so I'd imagine the Citrix server is located locally, but I don't know how the IT infrastructure is laid out here, so perhaps I shouldn't make those assumptions.


We're working a little closer with the IT department now, so hopefully we'll get some answers.


Thanks again!



1.5K Messages

8 y ago

Hello psteng,


Welcome to the forum.

We agreed with our community members' posts as well to resolve this VPN speed issue.

If you have any other question or can help another member, please post!




Thank you for that troubleshooting post!




Thank you for sharing that m.enet link and suggest for ptseng!