Friday, December 9, 2016

Skype for Business Online SIP URI Define or Change for Office 365 Online User

How is the SIP URI defined in Skype for Business Online?

Can the SIP URI be changed? - Yes!

I ran into an issue today, where we have registered an additional DNS Domain with the customer Office 365 tenant.
Problem was, the UPN and EMAIL address was still

It was necessary changing the SIP address to the new domain.

the User had:

but we need to change actually only the SIP address to

the command
Set-CsUser -identity user -SipAddress
is not working!

ERROR: Unable to set “SipAddress”. This parameter is restricted within Remote Tenant PowerShell.

see support statement:


What is important in Office 365 AZURE AD?

First activation of the tenant defines the default domain as where the UPN of user will be automatically :

Once you add the original domain into the tenant and make it the default domain the user UPN (only those with will be automatically changed too the new default domain with an automated Office 365 internal batch run.

If you define multiple DNS domains, you only one default domain. This default domain is automatically suggested once you create an Office 365 user account.
If you like creating a new user with different UPN/ default domain, change it during the creation task at the top of the create new user wizard (or if via PowerShell, define the DNSdomain there)

Therefore remember the following:

  • UPN (User principal name/ login name) = SIP URI
  • SMTP address can be set different from UPN to any registered DNS tenant domain.

Best Practice is UPN should be equal with the SIP URI and EMAIL address for best user experience)
If a users SIP address should be changed, you MUST change the users UPN.
to the domain/ username you want.

do this graphically within the tenant admin center (users)

B) Use the PowerShell

The user doesn't need to be disabled from any Office 365 service, rather changing the UPN will change the SIP address.
If you need to change the EMAIL/ SMTP address you can use the Admin Center or change it via PowerShell.

This article doesn't fully apply if you af DisSync/ AZURE AD Sync in place.
But the principles still apply in the same way.


Friday, December 2, 2016

Supporting Busy on Busy with Skype for Business

This should be just used as basic approach on how you can support busy on busy.

First you can check if the new APPLICATION was installed correctly:

The newly created appliance will be loaded during the Frontend server startup procedure and you will be able seeing a not in Event 30253, indicating the application was included in the loading process.

Next important, not to say most important tool ist LOGGING TOOL:
Here you will find a pre-defined set towards busy on busy.

Generally busy on busy messages look like this example below:

Content-Length: 0
Via: SIP/2.0/TLS;received=;ms-received-port=41538;ms-received-cid=9F6B100
From: "User1"<>;tag=8ea09bf2e6;epid=2983f4c267
To: <>;tag=C643D58961F545B
Call-ID: 734ea4e359617902c2098433b
Server: BusyOptions/
   1034;reason="Previous hop federated peer did not report diagnostic information";

Other Stack Traces and more you could search for are:

  • OnSipAudioInvite
  • GetIsTeamCall
  • GetIsRgsCall
  • GetIsDelegateCall
  • ShouldPrioritizeCall

Good luck troubleshooting....


Enabling Busy on Busy within Control Panel

The configuration advice and technical description can be found here:

Navigate to the Voice Policy in the Voice Routing Section
Here you can enable Busy on Busy on a GLOBAL Policy or based on USER/ SITE policies.