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Changing SIP address of OCS Enabled Users – What is the impact?

Posted by Milind Naphade on 13/04/2011

I was talking to one of my very good friends yesterday. He was asked to test the impact of changing SIP of the OCS enabled user accounts.

Honestly, its really tricky to answer a question when someone asks you about the predicted impact of changing SIP addresses. I was able to find something related to this here

The article linked above though said that Curtis (the blog author) did not test it change of SIP address in Group Chat.


I thought I could check some possibilities in my lab. The results from my lab are something like this.

  • Internal users to your SIP pool or for that matter entire organization will not be affected due to change in their SIP address.
  • The only adverse effect of changing SIP address is the dependant applications in the organization. If you have any application that uses the SIP address for sending IMs to the recipients then these applications would fail. I have a SCOM server in my environment which had a IM channel configured. The SCOM stopped sending emails after I changed SIP address of the user account which was a recipient for SCOM alerts on IM.
  • If you are federated with other organizations and you are also added as a contact in contact list of federated users then your presence to your contacts will not work.
  • Group chat will have no negative effects of changing the SIP address. (I didn’t observe any).
  • Outlook integration of MOC breaks if the SIP address is different than the primary SMTP address of the user mailbox on Exchange server.

As mentioned in the linked blog as well, OCS would generate a UID for each enabled user and it will be stored in the configuration database. Communicator uses this UID for conversation with other OCS enabled users. This is the key point here which keeps the functionality working even after there is a change in SIP addresses.

I would appreciate your comments on this post as there may be several things that I was not able to test.

One Response to “Changing SIP address of OCS Enabled Users – What is the impact?”

  1. Mihir said

    Hi Miling, we have exchange on premises, 2008 on premises and we are having error with go daddy ssl certificate for exchange. We do have local ca, how can we use the same to get certificate for Exchnage 2010.
    Also when we deleted the existing godaddy expired certificate all secure sites started to show the red flag in our internal network.

    I appreciate your insights. presently New Godaddy certificates are not authorized by windows.



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