Troubleshoot connectivity issues Outlook Anywhere Exchange 2013

Hi there,

As part of our Exchange 2010 -> 2013 migration we've transitioned CAS to Exchange 2013 2 weeks ago. Some 50 mailboxes have been moved to exchange 2013. Moving mailboxes for everyone is scheduled the 2nd week of july . Because our current version of Outlook is 2007 (migration to 2013 is due thissummer) we've configured NTLM authentication for OA.

Exchange setup: 8 Multirole (CAS/MBX) virtual (VMware) Servers: each 4 cores, 24 Gb memory (reserved) : Windows 2012 SP1, Exchange 2013 SP1 (15.0.847.4030)

Right now we're facing client connectivity issue's: Outlook Anywhere clients are continiously losing connection with exchange, some people (outllook 2007/exc. 2007) report every minute or worse.... Moving the mailboxes of affected people results in less problems: Sometimes no disconnects for 10 to 30 minutes, then reconnects every minute for some time.

We've already set the timeout for the oa-pool in our network proxy (riverbed steelapp) to 20 minutes and the minimum keep alive on the 2013 servers to 120 seconds which improved Oultook 2013 clients; before I experienced reconnects every minute, after every 10 to 30 minutes (with periods of reconnects every minute)

testconnectivity.microsoft.com gives positive results (apart from a nspi warning about server side encryption)

testing with rpcping according to http://blogs.technet.com/b/exchange/archive/2008/06/20/3405633.aspx gives some interesting results:

I've tested all (8) CAS 2013 servers over ports 6001, 6002 and 6003; each 100 rpcpings with a for loop: every response was either about 500 ms or about 21 Seconds ?!?

How can we furher troubleshoot the reason of the long reply time. Eventlogs (and SCOM with exchange 2013 MP) show no relevant events or alerts.

Part of the output of a rpcping

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {59b56c7f-af5d-4836-b701-92070f674de6}
 Completed 1 calls in 452 ms
2 T/S or 452.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {1197cd5e-c79d-4659-b598-3134c335b103}
 Completed 1 calls in 468 ms
2 T/S or 468.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {0cbaef91-ec96-402e-aa00-4913e2be1c51}
 Completed 1 calls in 483 ms
2 T/S or 483.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {525717e5-441b-4a8e-8398-dc86d38852c7}
 Completed 1 calls in 21450 ms
0 T/S or 21450.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {408d806d-ed5a-4f96-8c3c-2446a1d48ad8}
 Completed 1 calls in 21497 ms
0 T/S or 21497.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {3b441a9f-7606-4106-850f-fccb7c0f1bb1}
 Completed 1 calls in 21497 ms
0 T/S or 21497.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {bf994811-8528-433f-b532-f29d347fce5b}
 Completed 1 calls in 21590 ms
0 T/S or 21590.000 ms/T

 RPCPing v6.0. Copyright (C) Microsoft Corporation, 2002-2006
 RPCPing set Activity ID:  {ddb5248b-82aa-4586-b2f7-9c04c9922034}
 Completed 1 calls in 577 ms
1 T/S or 577.000 ms/T

Summary of all servers (test this morning)

I've repeated above test this afternoon: All test resulted in about 40-60 (of 100) replies >20 seconds