Introduction of New OAB Architecture in Exchange 2013 and Some General Troubleshooting methods

Question

Exchange 2013 is different from previous versions of Exchange server on architecture, some of the old features have been changed. In this FAQ, I will demonstrate the changes on OAB and list a common issue for your reference.
[Agenda]
1. Differences between Exchange 2007/2010 OAB and Exchange 2013 OAB
a. Generation
b. Distribution
c. Download
2. Common issue and troubleshooting
3. More information
[Difference between Exchange 2007/2010 and Exchange 2013 on OAB]
As we know, OAB in Exchange 2007/2010 has 3 points, OAB files generated from MBX server, distributed to CAS server and downloaded to Outlook client. However in Exchange 2013, these 3 points have a little different from previous servers. For example, the OAB
Distribution process doesn’t depend on Microsoft Exchange File Distribution service anymore. Now let me show you the changes of OAB in Exchange 2013.
[OAB Generation]
====================
Exchange 2007/2010:
1. OAB generation server is the specific MBX server which has –server property.
2. If MBX01 is down, OAB generation will be affected.
3. Previous Server using Microsoft Exchange System Attendant service for OAB generation.
4. OAB generation is a scheduled process. By default, OAB files generated at 5:00AM every day.
5. The OAB files which generated from MBX server are located in following path:
C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\OAB\GUID folder
Exchange 2013:
1. OAB generation server is the MBX server that hosts a special type of arbitration mailbox, called organization mailbox. Thus, the same OAB files could be generated from multiple
MBX servers.
2. If one of the MBX server down, other MBX server still have the ability to generate the specific OAB files.
3. Exchange 2013 server using OABGeneratorAssistant for OAB Generation.
4. OAB generation is a throttled process. It depend on the Server workload.
5. The OAB files which generated from MBX server are located in following path:
C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\OAB\GUID folder
[OAB Distribution]
====================
Exchange 2007/2010:
Previous Servers use Microsoft Exchange File Distribution service to distribute OAB files from MBX server to CAS server. The distributed oab files stored in CAS server.
Exchange 2013:
The OAB files doesn’t distributed to CAS server. The OAB files only stored in MBX server.
[OAB Download]
====================
Exchange 2007/2010:
If Autodiscover works fine, Outlook should use OAB URL to get the OAB files and download it.
If Autodiscvoer doesn’t work, authenticated users can also get the OAB from the CAS server local disk.
Exchange 2013:
Microsoft Exchange File Distribution service has been removed from Exchange 2013 and the OAB files stored in MBX server. CAS server will proxy all OAB download requests to the appropriate MBX server.
Outlook also use Autodiscover to get the OAB URL and download it.
[Common issue and Troubleshooting]
Issue: Outlook doesn’t download OAB files automatically. When I try to manually download OAB, get this error: Task xxx reported error (0x80190194): The operation failed.
Troubleshooting:
1. First, please run following command to check the information of OAB Generation Server.
Get-Mailbox -Arbitration | where {$_.PersistedCapabilities -like “*OAB*”} | ft Name, Servername, Database
Example result as below:
2. Please make sure the authentication settings and URLs are set properly.
3. Try to verify whether the OAB files generated from MBX server successfully. Path as below:
C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\OAB\GUID folder
4. If all of the settings above set correctly, please try to check Autodiscover. Run “Test E-mail Autoconfiguration” to check whether there is anything abnormal on OAB. If has, please search the error code on MS official documents.
5. If this issue is related to local cache, please try to delete the OAB caches from local PC and re-download OAB for testing. Path as below:
C:\Users\Administrator.CU1(different)\AppData\Local\Microsoft\Outlook\Offline Address Books
[More information]
http://blogs.technet.com/b/exchange/archive/2012/10/26/oab-in-exchange-server-2013.aspx
http://blogs.technet.com/b/exchange/archive/2013/01/14/managing-oab-in-exchange-server-2013.aspx
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Answer 1

Hi Techy,
According to your description, I am still not quite sure about your environment. Could you please provide more information about it, such as:
1. How many Exchange servers in your coexistence environment? One Exchange 2010 with all roles and one Exchange 2013 with all roles? Or several Exchange 2010 and multiple Exchange 2013?
2. Are there two sites in your environment? What’s the Exchange deployment in different sites?
3. Please confirm if both Exchange 2010 and Exchange 2013 are Internet-facing.
Additionally, if you are using different namespaces for different services for internal access and external accessing, we need to include all service namespaces in your certificate with IIS service. Personal suggestion, we can follow ED Crowley’s suggestion
to use split-brain DNS in your environment and only use the same namespace for Exchange service URLs.
The following article described the details about how to configure different namespace for Exchange services by using Load Balance in Exchange 2013:
http://www.msexchange.org/articles-tutorials/exchange-server-2013/high-availability-recovery/introducing-load-balancing-exchange-server-2013-part2.html
Regards,
Winnie Liang
TechNet Community Support