Forestprep, SIP domain used for default routing? RRS feed

  • Question

  • Hi,


    I stumbled over a question at a customer which I couldn´t answer.


    They have a Forest Root and a Child domain. OCS will be installed in the child.


    Which domain should we put in the field "SIP domain used for default routing"? We choosed the AD Child domain name now, because the servers and the users will be there, but I´m not definitely sure if this is right.


    The SIP domain for the user addresses is also different from the AD domain names.


    Can anybody help with this question?




    Friday, June 15, 2007 7:23 PM


  • Correct - it's called split brain DNS, and is a very common configuration.
    Tuesday, June 19, 2007 7:37 PM

All replies

  • The SIP domain you specify there should be the same as the SIP address you want.  So if the AD domain is ad.company.local and you want the SIP addresses to be user@company.com, the SIP domain should be company.com.
    Friday, June 15, 2007 9:04 PM
  • Hi Mike,


    thanks for your reply. But there is one other thing: We don´t have internal DNS for company.com, so if I choose company.com as the SIP domain it won´t be possible to do automatic logon for the clients. To make it work, I have to create a DNS zone for company.com in my internal DNS servers, put the DNS SRV record there and link it to my servers in the global.company.local domain.


    Am I right here?




    Tuesday, June 19, 2007 10:19 AM
  • Correct - it's called split brain DNS, and is a very common configuration.
    Tuesday, June 19, 2007 7:37 PM
  • Hey Mike,


    I am through to the "Configure Pool" step in the wizard (doing a consolidated enterprise topology) and had a feeling I misconfigured earlier when I went through and re-read the setup document.


    During the Prep Forest step I selected company.org as the SIP domain as it appeared in a drop-down list and I didn't believe at the time that it was a field I could type freely in. In reality all users have email addresses ending with company.com, even though they exist in an AD domain namespace of company.org.


    Can I fix this by using the OCS admin tool and modifying the global properties for "Forest - company.org" on the General tab to add the company.com SIP domain and make it the default routing domain? Or should I go back to the Prep forest step and redo from there? If I do go back, do I need to uninstall anything?


    You advice is appreciated.




    Morris Newman

    Wednesday, June 20, 2007 12:40 AM
  • Yes, you can change this on the forest properties by simply adding company.org to the list.  Just make sure your certificates are company.org if you're using TLS.
    Thursday, June 21, 2007 3:03 PM
  • Hi Mike,

    I also have the same question as Chris regarding the 'SIP domain used for default routing' and I am not sure I understand the reasoning behind your answer. . If the environment uses only one SIP domain for its users, I can sort of understand your answer. However, what if the environment uses three sip domains for users (us.domain.com, eu.domain.com and ap.domain.com) and the internal domains for AD/DNS are domain.org for root and us.domain.org, ap.domain.org etc... Then what should we select?? Do we just pick one of the three user sip domains as the ‘sip domain used for default routing’? which one? Why?

    I've been looking for information on this for a while, but can find/get a clear answer.

    Thanks very much,


    Thursday, October 8, 2009 8:09 PM
  • The default domain for SIP routing is used to append @<domain name> to SIP To/From fields that don't have a full SIP address by default (such as a phone number).  It's all behind the scenes stuff and as a result it doesn't generally matter which domain you select.
    Mike Stacy | Evangelyze Communications | http://www.evangelyze.net/cs/blogs/mike
    Thursday, October 8, 2009 9:06 PM