Unable to send a file between internal network and exernal network using Communicator RRS feed

  • Question


    Hi All,

       I have set up OCS standard server and edge server.

       IM, A/V works fine. but file transfer only works in internal network.

       when send a file frm internal network communicator to external network communicator, it fais, the error message appeard in communicator says:


    This may be due to firewall restrictions or network problems. Please try again. If you need further assistance, contact your system administrator.



    I can not figure out what's the reason caused to unable to do file transfer


    Any advice or suggestion will be appreciated.




    Thursday, September 20, 2007 10:15 PM

All replies

  • Hi Bo,

    In the following post you can find an answer on your question:



    Friday, September 21, 2007 4:43 AM


       I am still not able to do file transfer beweent internal user and external user.


      I capture the packet data in external user side when sending file from internal to external.


      I find the the internal local ip address (  appears in the external side which means

      OCS doesn't do network address translation when do file transfer.


    The follwoing highlight text is the data packet I capture in external

      16 9.032170 TCP 4354 > 6891 [SYN] Seq=0 Len=0 MSS=1460

  is the local ip address of external comuter. is the local ip address of internal computer.


    maybe my bad configuration of OCS caused the problem. but A/V works fine.





    Thursday, September 27, 2007 9:56 PM
  • Man i am having the same problem, u find de awser for this problem ?


    Friday, December 28, 2007 5:58 PM
  • In this case,


    OCS Act as a P2P connection.


    Ignore your OCS Server... you need to open traffic from LAN to Internet (Or Internet to LAN) to send/receive files with OCS, as Windows Messenger, AOL.....


    Follow the link that can be helpfull,






    Wednesday, January 2, 2008 12:53 PM