none
Very slow access to mapped local client drives (with RD Gateway) RRS feed

  • Question

  • Hi,

    for our published applications it is necessary to save files to the mapped/redirected local client drives (Session Collection -> Client Settings -> Enable redirection for the following: Drives).

    This is working, but very, very slow (i.e. for a small file < 1Mb it needs minutes!)

    I have setup an RDS environment as follows:

    • One 2012R2 Server (VM) for:
      * RD Connection Broker, Session Host, Gateway, Licensing, Web Access;
      * also RD Session Host for testing;
      * the server is within DMZ,      but has access to the corporate network (not Internet)
    • Several 2012R2 Servers (VMs):
      * RD Session Hosts
      * within DMZ
    • Several 2008R2 Servers (VMs):
      *
      RD Session Hosts (found a description to publish also 2008R2 App on the 2012R2 RD Web Access Portal)
      * within DMZ

    We thought about SSL, that this could be the reason or the certificate (but this looks good) or the AntiVirus software.

    I read different articles about the Bypass RD Gateway server for local addresses.

    When I check the Bypass RD Gateway server for local addresses box I can save files on the normal way (fast). But then I have only this (normal) fast access within the DMZ. Outside the DMZ the access is still very slow. (Also in this case the normal users have no access, only the administrators. I still don’t know why. But this will be the next step.)

    Then we thought that the way through two servers (RD Session Host and RD Gateway) could be the reason. However the file transfer of the published application from the RD Gateway Server is so slow, too.

    I've run out of ideas.

    So my question is:

    Why is the file download so extremely slow, when the RD Gateway is involved and only the file transfer to the local client drives. The normal file transfer to the local server drives is fast. Also the rest of the application is fast. When I use the normal Remote Desktop Session (mstsc.exe) everything is also fine.

     

    Thank you in advance for any help and hints you can give.

     Thomas

    Thursday, July 30, 2015 7:28 PM

All replies

  • Hi Thomas,

    When I check the Bypass RD Gateway server for local addresses box I can save files on the normal way (fast).

    Seems like a behavior by design to me, because when RD Gateway is used, network traffic is actually going through Internet.

    Here is a related thread below with detailed explanation for you:

    Remote App - saving files locally are extremely slow

    https://social.technet.microsoft.com/Forums/windowsserver/en-US/0a93c2e5-ff59-49e3-9211-06c0a50dd832/remote-app-saving-files-locally-are-extremely-slow?forum=winserverTS

    Best Regards,

    Amy


    Please remember to mark the replies as answers if they help and un-mark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Friday, July 31, 2015 1:42 PM
    Moderator
  • Amy,

    thanks for your answer.

    In our environment the DMZ/IDMZ is an internal network (VLAN) within our corporate network. The nonDMZ/nonIDMZ is our corporate network. We use the RD Web App/RD Gateway not through the internet. So everything is in the fast local network only separated with firewalls.

    I don't understand, why it needs so long to save a file to a redirected drive (if the Gateway is not bypassed).
    Again, when I do the same with bypass the RD Gateway - to save a file to another server (which is also within our IDMZ)- it is fast.

    Why is it so extrem slow? I can't believe that the RD Gateway slows down the whole save prozess so much.

    Why should the possibility be implemented to save file to redirected drive if it is not really usable, that you have to use VPN+TCP!?

    Thank you again for any help and hints you can give.

     Thomas

    Friday, July 31, 2015 8:19 PM
  • Hi Thomas,

    In our environment the DMZ/IDMZ is an internal network (VLAN) within our corporate network. The nonDMZ/nonIDMZ is our corporate network. We use the RD Web App/RD Gateway not through the internet. So everything is in the fast local network only separated with firewalls.

    In that case, then I would suspect that slowness is caused by redirection process.

    You may use Network Monitor to capture network traffic on clients and terminal servers to find out which stage is consuming most of the time.

    Network Monitor 3 Usage Videos

    http://blogs.technet.com/b/netmon/p/usagevideos.aspx

    Network Monitor 3.4 Downloads

    http://blogs.technet.com/b/netmon/p/downloads.aspx

    Best Regards,                   

    Amy


    Please remember to mark the replies as answers if they help and un-mark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, August 3, 2015 2:36 AM
    Moderator
  • Amy,

    we are still looking for the reason.
    I'm not yet so familiar with MS Network Monitor or wireshark, but I/we think that there is a difference in the packages inside and outside the internal DMZ.
    The packages inside were a little bit bigger and the distance/space between the packages were shorter.(Again, there is no Internet connection.) We are wondering which ports RD Web Access really needs. The only port which is open is the 443 (SSL) port. Is it possible that the RD Gateway uses more open ports for the internal data transfer!? (The bypass is still not activated.)

    Question:
    * Is the open port 443 for a fast connection/data transfer enough!?
    * Do we need UDP? (However I couldn't see a difference when I unchecked the UDP checkbox within the RD Gateway Manager.


    ___Thomas___

    Wednesday, August 5, 2015 2:02 PM
  • Hi Thomas,

    Here is an article below which enumerates ports required by RDS for you:

    Which ports are used by a RDS 2012 deployment

    http://social.technet.microsoft.com/wiki/contents/articles/16164.which-ports-are-used-by-a-rds-2012-deployment.aspx

    In addition, if workload on the RD Gateway is heavy, or computer resources are not sufficient, file transfer speed could also be impacted.

    You may use Performance Monitor to check performance for the RD Gateway server:

    Overview of Windows Performance Monitor

    https://technet.microsoft.com/en-us/library/cc749154.aspx

    Best Regards,

    Amy


    Please remember to mark the replies as answers if they help and un-mark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, August 10, 2015 9:32 AM
    Moderator
  • Hi Amy,

    thanks again for you help. I/we haven't found the right reason yet. Our connection is still bad.

    The current status:

    • The RD Gateway has less traffic, the result is the same in the night.
      What should I see in the Performance Monitor?
      TCP Connections:
      Image: System; local Address: IP Address of RD Gateway; Local Port: 443;
      Remote Address: Client PC;
      Latency: 180-240

     

    • RDP 8.0 WITH UDP activated is much faster than RDP 7.0 but only for these files which are small enough to save, for bigger files the connection stops.
    • RDP 8.0 without UDP is as slow as RDP7.0
    • Open a application with RD Web Access and (try to) save a file.
      Times for file transfer:
    • RDP 7.0 (2008R2): >50min!!!
    • RDP 8.0, no UDP 3391 (2012R2): stops after 30s (you have to restart the application to be able to save a file)!!!
    • RDP 7.0 + normal file transfer over TCP/IP (direct mapped drive, not redirected within RD): about 16 sec  :-)
    • RDP 8.0, no UDP 3391; Win7: very slow about 1-10kB/sec and stops after about 10 min (you have to      restart the application to be able to save a file)!!!
    • RDP 8.0 + UDP 3391; Win7:  stops after 30s (you have to restart the application to be able to save a file)!!!
    • RDP, no UDP 3391; Win7: save a word file 18MB 72 sec, load >15min.

    My questions:

    • Is it normal that the time to save a file with RDP 7.0 or RDP 8.0 without UDP takes so much, much longer within RD Web Access than the normal file transfer over TCP/IP?
      Is for this documentation available, that this is better understandable? The reason for why this is so slow? Is this the RD Gateway which slows down the transfer?
    • Why stops the file transfer after a certain time?
    • All our clients have RDP 7.0, so we are looking for a fast solution for RDP 7.0.
      Is this possible?
      We also don't want to open the UDP port if we had to use RDP 8.0, but want to have a normal transfer speed.
      Is this possible?
    • Why is the connection with UDP so much faster!? The TCP and UDP protocols are not so different that this huge speed difference is explainable. For small files it is about 10 times and more faster (for bigger files would be the same, but it stops).
    • There is always on only one (of both) UDP connections traffic, on the second one are only a few kB (~10) also when the other connections has more than 50,000kB. And it is always the some connection for save and load. For what is the second one? To save the word file (~18MB) was much faster than the load, more than 15 times. Why?

     

    Maybe someone had the same or similar  issues, I would be more than happy to finish this issue.

    Thank you in advance,

     Thomas


    ___Thomas___

    Wednesday, August 12, 2015 4:01 AM
  • Hi Thomas,

    Due to the complexity of the issue, I would suggest you contact Microsoft Customer Support and Services where more in-depth investigation can be done so that you would get a more satisfying explanation and solution to this issue.

    You may find phone number for your region accordingly from the link below:

    Global Customer Service phone numbers

    https://support.microsoft.com/en-us/gp/customer-service-phone-numbers/en-au?wa=wsignin1.0

    Best Regards,

    Amy


    Please remember to mark the replies as answers if they help and un-mark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Wednesday, August 19, 2015 6:54 AM
    Moderator
  • Hi _Thomas_,

    We also need to improve the performance of the redirected drives. How did you resolve this issue?

    Best Regards,

    Manisha

    Tuesday, November 10, 2015 4:51 PM
  • Manisha,

    I haven't found the answer I was/am looking for yet.

    What we did as a temporary solution is, we mapped a directory with normal file share/map folder on the session server. So we use a different file server which has access to the DMZ and outside. To save a file within our application to the mapped directory is as fast as a normal file transfer. (The next step is then to copy this file from the also mapped file directory on your Client to your local Client drive folder, also fast, because it is a normal file transfer.) 

    I still can not believe that the way with the redirected drives within RDS so slow is.

    However we also realized that we get better speed when we use also a 2012 R2 server as Session Host, currently we have a 2008 R2 (because for us this would be the better solution).

    => we will go back to the redirected drives with RDS (without an additional file server) but with a 2012 R2 Session Host.  But my recommendation is, try a 2012 R2 Session Host with a 2012 R2 Gateway. I say with a wordpad the opposite result. I have still no explanation for this.

    For better speed with 2012 R2 you also have to use UDP!
    For this you have to open port 3389 UDP (default). AND use the recent RD Client version RDP 8.0/8.1. You can see this in your RD Gateway Manager. If you get three connections (2xUDP, 1xTCP) you have a faster RDP connection with the recent version.

    Good luck and best regards,
     Thomas


    ___Thomas___

    Wednesday, November 11, 2015 4:04 AM