I installed 2010 into my 2007 environment this past Saturday. I have only moved over 1 "test" user to 2010. So far things appear to be working. The user can see calendar availability for the 2007 users and 2007 users can see its availability. Mail flow is fine. Public Folders are replicating. I am however seeing the event below logged on the 2010 servers referencing all of the 2007 servers several times a day. The 2007 servers are not recording any issues. I have 1 domain, 1 site, 2 subnets. The 2 subnets are seperated by a Cisco router with no access lists (wide open). I have looked through technet but all I am finding it references to cross-forest issues which is not my setup. Any help would be appreciated. Event Type: Error Event Source: MSExchange Availability Event Category: Services Event ID: 4002 Date: 6/6/2011 Time: 11:34:38 AM User: N/A Computer: Exchange2010ServerName.Domain.com Description: Process 1952: ProxyWebRequest CrossSite from S-1-1-0 to https://Exchange2007ServerName.Domain.com/EWS/Exchange.asmx failed. Caller SIDs: NetworkCredentials. The exception returned is Microsoft.Exchange.InfoWorker.Common.Availability.ProxyWebRequestProcessingException: System.Web.Services.Protocols.SoapException: Microsoft.Exchange.InfoWorker.Common.Availability.TimeIntervalTooBigException: The requested time duration specified for FreeBusyViewOptions.TimeWindow is too long. The allowed limit = 42 days; the actual limit = 61 days. ---> The requested time duration specified for FreeBusyViewOptions.TimeWindow is too long. The allowed limit = 42 days; the actual limit = 61 days. at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) at System.Web.Services.Protocols.SoapHttpClientProtocol.EndInvoke(IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.Proxy.Service.EndGetUserAvailability(IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.FreeBusyApplication.EndProxyWebRequest(ProxyWebRequest proxyWebRequest, QueryList queryList, Service service, IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.ProxyWebRequest.EndInvoke(IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.AsyncWebRequest.EndInvokeWithErrorHandling(). The request information is ProxyWebRequest type = CrossSite, url = https://Exchange2007ServerName.Domain.com/EWS/Exchange.asmx Mailbox list = <2007UserName>SMTP:2007UserName@domain.com, Parameters: windowStart = 6/1/2011 12:00:00 AM, windowEnd = 8/1/2011 12:00:00 AM, MergedFBInterval = 30, RequestedView = FreeBusy . ---> System.Web.Services.Protocols.SoapException: Microsoft.Exchange.InfoWorker.Common.Availability.TimeIntervalTooBigException: The requested time duration specified for FreeBusyViewOptions.TimeWindow is too long. The allowed limit = 42 days; the actual limit = 61 days. ---> The requested time duration specified for FreeBusyViewOptions.TimeWindow is too long. The allowed limit = 42 days; the actual limit = 61 days. at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) at System.Web.Services.Protocols.SoapHttpClientProtocol.EndInvoke(IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.Proxy.Service.EndGetUserAvailability(IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.FreeBusyApplication.EndProxyWebRequest(ProxyWebRequest proxyWebRequest, QueryList queryList, Service service, IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.ProxyWebRequest.EndInvoke(IAsyncResult asyncResult) at Microsoft.Exchange.InfoWorker.Common.Availability.AsyncWebRequest.EndInvokeWithErrorHandling() --- End of inner exception stack trace --- . Name of the server where exception originated: Exchange2010ServerName. Make sure that the Active Directory site/forest that contain the user's mailbox has at least one local Exchange 2010 server running the Availability service. Turn up logging for the Availability service and test basic network connectivity. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. Data:

I would first make sure that your Active Directory sites and subnets are properly configured and match what you expect in Exchange. Then I would follow the diagnostic steps in this article: http://technet.microsoft.com/en-us/library/bb218238(EXCHG.80).aspxEd Crowley MVP "There are seldom good technological solutions to behavioral problems."

The sites and subnets are correct in AD. That link is for issues with Exchange in a different site or forest, both of which are not the case here.

bump

Hi swinney, Did you follow below, and configured the legacy url properly: http://technet.microsoft.com/en-us/library/dd351133.aspx I have run into a issue like yours which caused by that. Could you please use the get-webservicesvirtualdirectory to retrieve some information, and post them here, we could do more research reagarding to your issue. Regards! GavinPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

get-webservicesvirtualdirectory shows my 2007 CAS servers pointing EWS to themselves while the 2010 CAS servers are pointing to the CAS Array name. The legacy url is used only if you expose Exchange to the internet for OWA, Outlook Anywhere and/or Active Sync right? If that is the case that has never been allowed here nor will it be in the future. If I am not correct please let me know.

Exchange 2010 CAS redirects to the legacy URL for mailboxes on back versions of Exchange regardless of whether you expose it to the Internet.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."