Moving from On-Premises to Skype for Business Online

This is a gotcha which took me two days to figure out. I was moving a customer from a broken Skype for Business on-premises to O365 Skype for Business Online.

Why go through the pain of hybrid, if the users never used the system in the first place. What I found is there is a lack of documentation on what are the steps to move in a big-bang scenario. So here goes....

1. Remove all users from your on-prem deployment
2. Make sure the users are not licensed for Skype for Business Online yet (if they are, remove it)
3. Make sure that "ALL" msRTCSIP-* attributes are null, and have propagated to all your DCs
4. Do another directory sync to O365 using your AADConnect server
5. Assign License on O365
6. Test User Connectivity

What got me here was step "3" .. All attributes were Null except for msRTCSIP-DeploymentLocator which was set to "SRV:" ... in a normal deployment this would be good because it means automatically detect the server. In O365 world, this means the user is On-Prem and don't enable them for Skype for Busienss.

Powershell Command to remove it..

 
Get-ADUser -SearchBase "OU=Users,DC=contoso,DC=local" -Filter * |Set-ADUser -Clear "msRTCSIP-DeploymentLocator"
 

Changing the primary SIP domain

Recently I came across a situation where it was necessary to change the primary SIP domain for a Lync 2013 customer (although this will work for any Lync or Skype for Business deployment). This is not a very difficult process but there are a few gotchas which I would like to share...

1. Make sure that you change the SIP address for all your users after making the change to the new SIP domain
2. Make sure you run the bootstrap after you have made the change on all servers
3. Make sure you modify all your RGS workflows to use the new SIP domain
4. Finally, and the hardest one (because its not documented anywhere); you will need to manually edit the application contacts using ADSIEdit.exe to use the new SIP domain

 Changing the Application Contacts

First open ADSIEdit and go to the configuration node, and navigate to the Application Contacts folder:

 Once there, open each entry and modify the msRTCSIP-PrimaryUserAddress and Proxy address to use the new SIP domain:

 

Don't forget to restart the services that you have changed !!