We were facing poor performance of Microsoft Exchange across WAN. It prompted us to deploy distributed exchange servers to support our local users. But it is expensive, difficult to manage, and puts our confidential data at risk.Is there any solution to this problem?

Are you using Outlook cached mode? Consider using OWA only for remote client access Deli

Actually, we opted for Outlook 2003's cache mode hoping that it might fix our WAN related issues. However, it has been able to remove only the latency issue and rest of the problems still remain unresolved.Any help will be greatly appreciated.

What are the rest of the problems you are facing? Deli

If you dont want a spread out Exchange organization, then there is not much option other than to get more bandwidth or devices that compress traffic going across WAN.

what version of exchange? If you are not in "native mode" you could be missing out on some bandwidth benefits. http://support.microsoft.com/kb/270143

Deli,The rest of the problems are related to the performance over the WAN."Cache Mode" attempts to hide performance issues over the WAN associated by preemptively downloading all new e-mails and their attachments from the Exchange server to a cache of storage on the local hard disk of the Outlook client workstation.Thanks.

I know that nortel has solutions for this: http://www.nortel.com/products/01/bcs/collateral/nn117160.pdf Deli

There are a couple of issues in running Exchange over a WAN connection - bandwidth and latency. You should configure the users to use Outlook in cached mode to reduce the bandwidth utilisation but this does not help with latency. If the Outlook users are connected to a mailbox with high latency to the Exchange server there will be a bad experience for the end users. You can reduce (or remove) this for the users by configuring the Outlook client in the locations that have high latencyto run in using RPC over HTTPS or Outlook Anywhere. This will not speed up the time to download the emails or look up calendars or the like, but it will reduce the apparent slowness of the client. Additional tasks would be to configure the Outlook clients to download headers before full items and also reduce the number of email items in the critical folders such as the inbox. This number should be under 1000 or 3000 depending on your performance requirements and what you read. Also keep in mind that in Exchange 2003 there is LOTS of traffic generated between the Exchange front end server and back end server so if these are in different locations, they will cause LOTS of traffic. Cheers, Rhys

The Outlook 2003 client does not display the new e-mail to the end-user until it has been completely downloaded, along with all its associated attachments. When the end-user finally sees the new e-mail and desires to open it, the data is fetched from the local hard drive cache of the Outlook client workstation. This gives just an illusion of fast performance.Is there any such technology that makes Microsoft Outlook/Exchange 2003 work with or without cache mode, and can display real performance results?

OK you can't expect Exchange/Outlook to solve you WAN connection speed problems Cached mode resolves the outlook hangs when a large message is openend Download Headers can increase the performance of new mail messages But you can't compare a highway with a dirt road and expect the same speed limits Deli

You can do some things like use a WAN acceleration product (Cisco WAAS does a very good job), other than that you need a bigger pipe if you want the messages to come down faster. Adding Exchange mailbox servers out at these sites doesnt solve the problem, it only hides it because the user doesnt get to see the mail at all until it's been transferred to their mailbox. It would also add a lot of complexity and costs to your deployment OWA would help to "hide" this somewhat in that they would see the message in their mailbox "immediately"; however they would experience slow speed as soon as they tried to download the attachment. I would focus on setting realistic user expectations, forcing everyone to use cached mode, using WAN acceleration, and where necessary getting a bigger pipe. There is no magic bullet. Erik