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Accessing Skype web services from Exchange RRS feed

  • Question

  • Hey all. I have my Skype for Business installation integrated with my Exchange environment for archiving and server side conversation history. In my Exchange server, I see the following error periodically:

    

    FYI webexternal.DOMAIN.com is the fqdn of my external Skype web services. Now I will say - I know EXACTLY what is causing this. Right now our firewall isn't really doing any kind of hairpinning and all of our Skype services except the actual internal pool fqdn are set in DNS (both private and public) to point all traffic to the public IP addresses of our edge servers/reverse proxy at our data center (I have everyone going external because we do not use any kind of MPLS, we use all IPSec VPN tunnels between about a dozen sites and pointing external cuts down on the video latency). So since Exchange is also in that same data center, when it queries DNS for the webexternal address and sees the public IP address of the same data center it lives on, it tries to connect to that public IP and fails because hairpinning is not happening.

    My question is, what exactly is Exchange trying to do here that it needs to connect to SKype web services? I can see why Skype connects to Exchange Web Services, but I'm not sure why Exchange would connect to Skype in this manner (over web services). I would be willing to at least consider either getting hairpinning from Exchange to that public IP set up or to create hosts file entries on my Exchange servers to point the external web services requests to the internal IP's of my FE servers, but before I even consider something like that I would like to know what the potential issues of ignoring these warnings may be. I haven't seen any issue arise from this yet and I don't want to fix something that isn't broke unless I have a good reason.

    Thanks!


    • Edited by Brolide Monday, August 29, 2016 1:55 PM More wording
    Monday, August 29, 2016 1:53 PM

Answers

  • Brolide,

    Event 5/6/7 indicates that a device/client is subscribing a server event, but the device/client doesn't respond when the server tries to notify, so the error events have been triggered.

    Check the EWS traces on the CAS server IIS log during that time to take a look further into what is going on.

    -Don

    Monday, August 29, 2016 6:54 PM
  • Hi Brolide,

    Agree with Don, please check the IIS log on Exchange CAS server, see where the requests came from, then check if that client experiences any problems about Outlook & SFB client. As it is just a warning, if no problem, it would be safe to ignore it.

    Best Regards,
    Jessie Yuan

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

    Tuesday, August 30, 2016 7:33 AM

All replies

  • Brolide,

    Event 5/6/7 indicates that a device/client is subscribing a server event, but the device/client doesn't respond when the server tries to notify, so the error events have been triggered.

    Check the EWS traces on the CAS server IIS log during that time to take a look further into what is going on.

    -Don

    Monday, August 29, 2016 6:54 PM
  • Hi Brolide,

    Agree with Don, please check the IIS log on Exchange CAS server, see where the requests came from, then check if that client experiences any problems about Outlook & SFB client. As it is just a warning, if no problem, it would be safe to ignore it.

    Best Regards,
    Jessie Yuan

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

    Tuesday, August 30, 2016 7:33 AM