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Over the next few weeks I will be blogging about some of the cool new features in Branch Repeater 5.5.
First up -- Exchange (MAPI) acceleration.
Everyone knows that Microsoft Exchange is the dominant enterprise email server commanding over 65% of the market. Most end users connect to their company's Exchange Server using a version of Microsoft Outlook installed on their desktop. MAPI (or Messaging Application Programming Interface) is the application layer protocol that Outlook email clients use to communicate with an Exchange Server.
As businesses have centralized their Exchange Servers in the datacenter, MAPI has become a top protocol operating over the WAN. By its nature MAPI is a "chatty" protocol which means it performs poorly in WAN environments. Branch Repeater 5.5 now automatically detects MAPI connections and responds by pipelining multiple MAPI messages together for transport across the WAN. By eliminating protocol chattiness, Branch Repeater makes Outlook/Exchange significantly faster over high latency connections.
Large email attachments are another cause of poor email performance. Branch Repeater addresses this issue by automatically compressing and de-duplicating email attachments.
The results are nothing short of stunning. In many cases you will see performance improvements of 10, 20 or even 50x.
Beyond accelerating the end-user experience, this feature also has a dramatic impact on reducing network bandwidth consumption. Imagine a user in a branch office emailing a 10MB attachment to ten other people in that office. Without Branch Repeater, the entire 10MB file must be transmitted to the Exchange Server and then transmitted back to the branch office ten times - once for each recipient. With Branch Repeater, the attachment is only transmitted across the WAN once.
Branch Repeater's Exchange (MAPI) acceleration is not just for branch offices. The Repeater Plug-in for Citrix Receiver brings this functionality to individual remote users working from home or on the road. Now you don't have to wait forever to download that large attachment while working in your hotel room.
Earlier I said that most users connect to their company's Exchange server using a locally installed version of Outlook. That makes sense since many users need offline access to their email. But wait a minute... XenApp also provides offline access to applications with application streaming. And guess what? A streamed version of Outlook talks MAPI too. So whether you have locally installed Outlook clients or are streaming Outlook with XenApp -- you need to try out Branch Repeater 5.5 in your network.
Comments (3)
Jul 23
Niels Hanssen says:
Sure, a lot of company's are still using MAPI, but with the "newer" versions of ...Sure, a lot of company's are still using MAPI, but with the "newer" versions of exchange you can run rpc over https.
Is this is also a scenario in which you would recommend to use the branch repeater, or would you suggest to use the netscaler if you are using rpc over https?
I can't wait for the next part of this article!
I am wondering if it's already possible to scale bandwidth based on ICA virtual channels, using the repeater..
Jul 24
Timothy Bardzil says:
In Exchange 2007 the default communication mode is still native MAPI. RPC over H...In Exchange 2007 the default communication mode is still native MAPI. RPC over HTTPS (now called Outlook Anywhere) has some nice benefits but requires quite a bit of additional configuration on the Exchange Server.
http://technet.microsoft.com/en-us/library/bb123889.aspx
For RPC over HTTPS you still get the benefits of Branch Repeater's TCP flow control to mitigate TCP performance penalties due to latency and packet loss. Depending on your link conditions you could see a 2-3x performance boost.
I would not expect to see any additional benefits using a NetScaler. Even if you can terminate the HTTPS session, by default all Exchange email attachments are pre-compressed. To do any more advanced compression (like the byte-level caching we do with Branch Repeater) you have to be able to negotiate with the Exchange Server to disable the deafult compression of email attachments.
Stay tuned for my next blog where I will be discussing the new Branch Repeater appliance that is built on Windows Server 2008.
Aug 03
Anonymous says:
Surely all good networks would have Branch Repeater AND NetScaler in them?Surely all good networks would have Branch Repeater AND NetScaler in them?
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