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Remote Exchange 2007 CAS Server? RRS feed

  • Question

  • Hello

    We are running Exchange 2007 SP3 with 4 x CCR Clusters in our London Office.

    We have both Outlook 2003 and Outlook 2007 clients in all global offices so still use Public Folders and Web based Free Busy\Availability Service.

    We are about to make some infrastructure changes to one of our Overseas offices, replacing their current Exchagne Implementation.

    I have one quick question, in the remote office in question, the user's mailboxes (100+) will be hoested in London and accessed via Cached Mode.

    Is it possible or worthwhile for us to Install a Remote CAS Server to speed up the Availability\Autodiscover performance?

    Also, does anyone have any articles to show where\how this was done?

    Thanks in advance.

     

     

    Thursday, November 24, 2011 1:36 PM

Answers

  • Hi,

    No - that is not worthwhile.

    Autodiscover is just a small XML file sent to the client and the availability service would sent the request to the CAS server in the MB site anyway

    Leif

    • Proposed as answer by Xiu Zhang Tuesday, November 29, 2011 3:55 AM
    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:12 AM
    Thursday, November 24, 2011 2:11 PM
  • Not for autodiscover, but for availabilty it might be worth having a PF database there, if WAN is a concern and you would prefer to have Free/Busy at the remote office should the WAN be down.
    Sukh
    • Proposed as answer by Xiu Zhang Tuesday, November 29, 2011 3:55 AM
    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:12 AM
    Thursday, November 24, 2011 10:31 PM
  • Hi,

    We recommend to implememt at least one CAS server in each AD site.

    For your question, please consider the following,that is exactly the same as Sukh828 said: 

    If the target mailbox is in another AD site:

    a. Then the CAS server will make an HTTPS connection to the target CAS server.

    b. The target CAS server will obtain the F/B information by communicating over MAPI to the mailbox server and then send it back to the source CAS server.

    • Proposed as answer by Xiu Zhang Tuesday, November 29, 2011 3:55 AM
    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:13 AM
    Tuesday, November 29, 2011 3:55 AM
  • Xiu

    We do have Outlook 2003 clients at the moment, but all users will be moving to Outlook 2007\10.

    The users mailboxes will be hoested in the Primary Site (London), but we want to install a CAS Server in their local Site to speed up Calendar lookups.

    No Other Exchange Server Roles will be installed in the local site.

    In this Whitepaper on Technet, it states

    "In environments where Outlook 2007 is deployed in remote sites that do not have Exchange 2007 Mailbox and Client Access servers, you can use site affinity to configure the SCP objects for Outlook 2007 clients to use SCP objects that are physically closer. For more information, see How to Configure the Autodiscover Service to Use Site Affinity later in this white paper."

    http://technet.microsoft.com/en-us/library/bb332063%28EXCHG.80%29.aspx#ConfiguringADSiteAffinityHowTo

    Will this solution work?



    Yes, if you do not have Mailbox and CAS server installed in the same site as the user. You can specify the CAS that the client can connect.Thus client user can connect to the specified CAS directly.

    But please note, the request handled by the specified CAS also will be proxy to the CAS which is in the same site as the user mailbox in.

    Xiu

     

     

     


    Xiu Zhang

    TechNet Community Support

    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:13 AM
    Friday, December 2, 2011 2:37 AM

All replies

  • Hi,

    No - that is not worthwhile.

    Autodiscover is just a small XML file sent to the client and the availability service would sent the request to the CAS server in the MB site anyway

    Leif

    • Proposed as answer by Xiu Zhang Tuesday, November 29, 2011 3:55 AM
    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:12 AM
    Thursday, November 24, 2011 2:11 PM
  • Not for autodiscover, but for availabilty it might be worth having a PF database there, if WAN is a concern and you would prefer to have Free/Busy at the remote office should the WAN be down.
    Sukh
    • Proposed as answer by Xiu Zhang Tuesday, November 29, 2011 3:55 AM
    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:12 AM
    Thursday, November 24, 2011 10:31 PM
  • Hi,

    We recommend to implememt at least one CAS server in each AD site.

    For your question, please consider the following,that is exactly the same as Sukh828 said: 

    If the target mailbox is in another AD site:

    a. Then the CAS server will make an HTTPS connection to the target CAS server.

    b. The target CAS server will obtain the F/B information by communicating over MAPI to the mailbox server and then send it back to the source CAS server.

    • Proposed as answer by Xiu Zhang Tuesday, November 29, 2011 3:55 AM
    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:13 AM
    Tuesday, November 29, 2011 3:55 AM
  • Thanks Xiu Zhang.

    Yes, we thought that the remote CAS Server would act as a local replica for Free\Busy, which would speed up Outlook Calendar sharing.

    As we are running Exchange 2007 and Outlook 2007\10 then would we not need the "availability service - web-based replica" rather than a PF Database as you said?

    How would this work?  Would we need specify a CAS Server for the user accounts of the users in the remote office?

    Thanks

     

    Tuesday, November 29, 2011 12:07 PM
  • Hi,

    Please verify if you have outlook 2003 in the envrionment.

    If yes, the we do not need to retrive free/busy information from public folder. If not, free/busy information will be published in local public folders.

    When outlook user access mailbox, it will first try to query AD to obtain the mailbox server information. If it is not the same site as the user, then CAS server will proxy the request to the target CAS server(CAS in the same site as Mailbox server).Outlook 2007 uses the Autodiscover service to obtain the URL of the Availability service.

    So your question, we need to ensure we have at least one CAS server in each site. It will try to find the CAS server in the remote site automatically.

    What does Exchange 2007 Availability Service do?

    http://blogs.technet.com/b/exchange/archive/2006/10/23/3395177.aspx

    Configure Exchange Services for the Autodiscover Service

    http://technet.microsoft.com/en-us/library/bb201695.aspx

    Xiu

     

    Wednesday, November 30, 2011 3:03 AM
  • Xiu

    We do have Outlook 2003 clients at the moment, but all users will be moving to Outlook 2007\10.

    The users mailboxes will be hoested in the Primary Site (London), but we want to install a CAS Server in their local Site to speed up Calendar lookups.

    No Other Exchange Server Roles will be installed in the local site.

    In this Whitepaper on Technet, it states

    "In environments where Outlook 2007 is deployed in remote sites that do not have Exchange 2007 Mailbox and Client Access servers, you can use site affinity to configure the SCP objects for Outlook 2007 clients to use SCP objects that are physically closer. For more information, see How to Configure the Autodiscover Service to Use Site Affinity later in this white paper."

    http://technet.microsoft.com/en-us/library/bb332063%28EXCHG.80%29.aspx#ConfiguringADSiteAffinityHowTo

    Will this solution work?


    Thursday, December 1, 2011 10:48 AM
  • Hi,

    Not sure why you think that this will speed up calendar lookups??

    If you have a local CAS server users will connect to this CAS server for availability data - as this local server have no local mailboxes it will send the request to the remote CAS server which will collect the required data and send it back to the local server which in turn will return it to the users.

    With no local CAS server the same operations will be performed but with no CAS server in the middle to slow things down.

    Leif

    Thursday, December 1, 2011 1:56 PM
  • Hello leif

    Would the CAS Server in the remote site not Cache the Calendar info.

    Thanks for your comments and assistance.

    Can you confirm that what I am proposing is possible?

     


    Thursday, December 1, 2011 2:50 PM
  • no, the f/b is retrived from the mailboxes directly by CAS.
    Sukh
    Thursday, December 1, 2011 2:57 PM
  • Hi,

    I guess that it is possible to add a CAS server in the remote site but I am almost sure that you don't gain anything by doing so (only one more server to manage).

    And as Sukh says, availability data is retreived directly from the mailboxes by the CAS server in the same site as the mailbox server when the data is requested.

    Leif

    Thursday, December 1, 2011 3:43 PM
  • Xiu

    We do have Outlook 2003 clients at the moment, but all users will be moving to Outlook 2007\10.

    The users mailboxes will be hoested in the Primary Site (London), but we want to install a CAS Server in their local Site to speed up Calendar lookups.

    No Other Exchange Server Roles will be installed in the local site.

    In this Whitepaper on Technet, it states

    "In environments where Outlook 2007 is deployed in remote sites that do not have Exchange 2007 Mailbox and Client Access servers, you can use site affinity to configure the SCP objects for Outlook 2007 clients to use SCP objects that are physically closer. For more information, see How to Configure the Autodiscover Service to Use Site Affinity later in this white paper."

    http://technet.microsoft.com/en-us/library/bb332063%28EXCHG.80%29.aspx#ConfiguringADSiteAffinityHowTo

    Will this solution work?



    Yes, if you do not have Mailbox and CAS server installed in the same site as the user. You can specify the CAS that the client can connect.Thus client user can connect to the specified CAS directly.

    But please note, the request handled by the specified CAS also will be proxy to the CAS which is in the same site as the user mailbox in.

    Xiu

     

     

     


    Xiu Zhang

    TechNet Community Support

    • Marked as answer by Xiu Zhang Friday, December 2, 2011 9:13 AM
    Friday, December 2, 2011 2:37 AM