OCS2K7 - File Transfer Issue External-Internal/Internal-External RRS feed

  • Question

  • Hi everybody,


    we experienced problems with File Transfer on peer2peer communication between 2 communicators 2007 clients.

    File transfer has been enabled. No File Transfer filter.

    Everything works fine in internal mode (internal-internal)

    Everything works fine in external mode (external-external)

    But it does't work in external-internal or internal-external mode.

    Of course we have opened Enterprise and workstation Firewall ports 6891-6901 TCP.



    Network trace shows that there is problem with the IP @ of the external client (the internal client tries to send the file to private IP @ of the external client) (external client is behind an XDSL Box)


    No problem during A/V , presence or IM ....

    Wednesday, October 17, 2007 7:43 AM

All replies


    I have the same problem.


    When I trace request in ISA Server, I discover that my computer send a request to a private IP to an external client, when I receive a file.


    Any idea ?

    Tuesday, December 18, 2007 4:29 PM
  • Any new findings on this issue???
    Monday, June 23, 2008 2:32 PM
  • There is no solution for this problem

    As it is peer to peer it does not work well with NAT


    Monday, June 23, 2008 10:19 PM
  • Deli is correct.  It is a peer to peer connection.  It would take one heck of a proxy to figure it out. 


    Office Communicator



    Port ranged used by Office Communicator for file transfer.


    It may be possible if you are using a NAT pool and have these ports open.  It would probably require some kind of fixup of the ports as well.  If you are in a PAT pool, there is now way.


    Tuesday, June 24, 2008 3:49 AM
  • IPv6 will solve this problem in the future Smile

    Tuesday, June 24, 2008 9:18 AM