Posted by: Anthony Drewery | March 20, 2006

Exchange 12 Topology

I’m still trying to get my head around Exchange 12 mail flow and message routing but I’m sure it’ll become clearer once we get the servers up in the other sites. I’m hampered a little by the fact that this beta doesn’t have a GUI for configuring the bridgehead servers so I can’t have a nose around the settings.

From my understanding so far Exchange 12 is an Active Directory site aware application so it is very important that your Subnets and IP Site Links are correctly defined in AD Sites and Services. After checking available hardware in the various regions I’ve settled on 4 AD sites in the sandpit environment. These are Crawley (UK), Tampa (US), Santos (Brazil) and Montreal (Canada). The sites will be fully meshed with IP Site Links. To begin with the links will have uniform costs but at a later stage I’ll be investigating whether adjusting the values has any impact on mail routing within our organisation.

AD Site Overview
For the Crawley site we’ll have 4 servers initially. There will be a domain controller containing the global catalog, a mailbox server, a server with the bridgehead and client access roles and a gateway server. According to the release notes the gateway server role hasn’t completed the security pass. Therefore we’ll keep it on the internal network and route email to/from it via a Mailsweeper server in our DMZ.

I’ve placed a diagram of the Crawley topology below. Click on it for a larger version.

Crawley Topology

I’ll provide more information once the other sites are running and we’ve had a chance to experiment with connectors and mail routing. There’s no point me regurgitating the help files at this stage when I don’t have a decent understanding.
[tags]Exchange 12[/tags]


  1. Interesting setup, please keep posting on your trials, my company has setup a smaller sandbox for us to do testing with vista/longhorn but they do not want to look at E12 yet ( i can’t understand why but they should be :)) anyway curious if you will be trying the EDGE service on the mail sweeper server as well or just using mail sweeper to handle Mail hygiene

  2. Why woudl you install an exchange mailbox server in each of your 4 geographical sites. With Excange 12 it should be possible to centralise all of this.

  3. With our live Exchange 2003 we do centralise in two main data centres (UK & USA) and two smaller sites (Australia & Brazil). These four routing groups support staff in offices all around the globe. We have a total of 198 nodes on our WAN which range from small 1 or 2 user offices connecting via a VPN to large service centres with several hundred employees. When centralising you need to condsider your WAN infrastructure, bandwidth and network latency. Even using Outlook 2003 in cached mode you need to take into account other factors like the downloading of the offline address book and the impact it could have, the type of email traffic and interconnected systems like Cisco Unity voicemail.

    Our Exchange 12 environment is a sandpit and as such we’re trying to make it as complex as possible initially. This will allow us to test all of the features and to investigate E12’s close relationship with the active directory topology.

  4. “Possible” doesn’t always mean “a good idea”.

  5. are you guys going to test the Unified messaging system as an alternative to the Cisco Unity system? or can the 2 be used in conjunction? i remeber during some e12 webcasts that using one or the other would be indeal

  6. I would like to be able to try the E12 Unified Messaging but unfortunately at this current stage of testing the beta we don’t have the budget or hardware. This will change though when the final version of E12 is released and we switch to a live pilot. We have Cisco Unity linked into our current Exchange 2003 system.

  7. Hi, just ran across this now in a search… if you still have questions, feel free to drop me a line at kclemson at microsoft dot com and I’ll help out with some e12 info. We also had a few public webcasts in the last few months that might help, links are on from a couple of months ago.

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