Outlook Web Access times out and asks for authentication again

[outonalimb]

We have a head office site where we host our Exchange 2003 server. This server also runs IIS which we use for giving our employees OWA.

We also have 10 branch offices on different subnets that are linked to head office via a MPLS network. When employees from branch offices connect to OWA to check their e-mail, OWA times out after 20 seconds and asks them to reauthenticate. This continually happens and is annoying users. This has happened ever since we installed Exchange 2003 2 years ago and also on Exchange 5.5 prior to that.

Employees who check their e-mail via OWA at head office (on the same subnet as the Exchange server) have no problems at all. Also, people coming in over the internet from home for example also have no problems. We forward port 80 to the server through our firewall to allow external access.

The question is does anyone know or have an inkling to why our branch office users are having this OWA timeout problem?

Our head office subnet is: 192.168.1.x
Our branch office subnets are: 192.168.2.x, 192.168.3.x and so on...

 

[PU36]

By default, when OWA has forms-based authentication enabled, sessions have a 15-minute inactivity timeout for public or shared computers and 24 hours for a private computer. If you're using a public computer to compose a long email message that takes more than 15 minutes to write, the session will time out and you won't be able to send the message. You can change this timeout value (which is the cookie lifetime) by using this procedure:

1. Log on to the Exchange server as an Administrator.

2. Start the registry editor (regedit.exe).

3. Navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA subkey.

4. From the Edit menu, select New - DWORD value.

5. Enter a name of PublicClientTimeout and press Enter.

6. Double-click the new value and set it to the desired number of minutes before a timeout (1 to 4320), set the type to decimal, and click OK.

7. To set the timeout period for a private client, repeat the process of creating a DWORD value, but this time enter a name of TrustedClientTimeout and again set the value to the number of minutes before a timeout (The value for private computers should be significantly higher than for public computers.)

8. Stop and restart the World Wide Web (WWW) Publishing service by using these commands at the command line.

net stop w3svc net start w3svc


(referenced from

http://www.windowsitpro.com/article...fy-the-exchange-server-2003-owa-timeout.html)

 

[outonalimb]

Hi, thanks for your response.

However, I have seen this solution before but it doesn't work in my scenario. We have forms based authentication but it times out after 20 - 30 seconds at the most. From a public IP (i.e. me at home checking e-mail at home) the problem doesn't occur - it times out after 15 minutes like it should.

The problem only occurs over our private WAN. People at our branch office checking e-mail via OWA get time outs after the mentioned 20 seconds.

We don't have any proxy settings turned on in IE, etc. I really am at a loss.

Can anyone else shed a light on this?

 

[hanoirocks]

Are your branch offices connected via VPN?
Is the timeout still the same if they check the "Private computer" option?

 

[llevon]

The OWA is it direct to the front-end server or published through ISA?

There are timeouts in ISA when publishig OWA.

Steve