BUG CSCue31224 [ CUC 9.x and Exchange 2010 SIB UM doesn’t work for large mailboxes ]

Symptom:

Customer has certain users that you can’t get SIB UM to work yet many others on the same Exchange 2010 and mailstore works fine. They see this for the users affected in the SIB traces…
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11:28:14.184 |16230,outlook.office365.com,{98c6481a-fa6e-483f-815e-fa6a9a81b250},CsEws,14,1:0) Header:
11:28:14.184 |16230,outlook.office365.com,{98c6481a-fa6e-483f-815e-fa6a9a81b250},CsEws,14,2:0) FindItemResponseMessage_ResponseClass: Error
11:28:14.184 |16230,outlook.office365.com,{98c6481a-fa6e-483f-815e-fa6a9a81b250},CsEws,14,2:1) MessageText: The server cannot service this request right now. Try again later.
11:28:14.184 |16230,outlook.office365.com,{98c6481a-fa6e-483f-815e-fa6a9a81b250},CsEws,14,3:0) ResponseCode: ErrorServerBusy
.
.
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11:28:16.257 |16230,outlook.office365.com,{98c6481a-fa6e-483f-815e-fa6a9a81b250},CsMbxSync,23, m_spExchMailStoreProvider->GetMessages() FAILED – hr = 0x80046F04: E_MC_COULD_NOT_CONNECT on line 87 of file CCsMsExchMbx.cpp
11:28:16.257 |16230,outlook.office365.com,{98c6481a-fa6e-483f-815e-fa6a9a81b250},CsMbxSync,23,m_spForMbx->GetMessagesFromStore() FAILED: E_MC_COULD_NOT_CONNECT on line 104 of file CCsMsMbxLink.cpp
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Conditions:So far we are seeing these cases on CUC 9.x and Exchange 2010 back end.

Workaround:So far a work around seems to be to adjust the Exchange 2010 throttling policy like this…

Set-ThrottlingPolicy -identity “UNServicesPolicy” -EWSFindCountLimit 25000

For all effected users, we need to apply Throttling policy per mailbox if the 2010 Exchange Server version is Exchange 2010 Service Pack 2 (SP2) Update Rollup 4 (RU4) or above. For earlier 2010 Exchange Server versions throttling policy correction needs to be applied per service account which is impersonating effected users.

More Info:

Please refer below link for detailed information on changing throttling values:

http://preview.cisco.com/en/US/docs/voice_ip_comm/connection/9x/unified_messaging/guide/9xcucumg020.html#wp1343905

As code fix, through following defect Paging functionality has been implemented to resolve this issue: CSCtz20281 (Add paging support to FindItem requests)

The only fix right now is to create a throttling policy with unlimited EWS connections and then add the affected users to that policy within exchange.  Other than that, there have been no new updates.  Thanks

http://www.cisco.com/c/en/us/support/docs/unified-communications/unity-connection/116488-trouble-ews-00.html