Tweaking OCS for PIC with Windows Live/MSN Messenger

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Summary:

 

Windows Live/MSN Messenger defines both Minimum and Maximum values for Presence subscriptions. If the SUBSCRIBE method uses a value out of this range, it may result in a SIP failure. The minimum value is 3600 seconds and the MAX value is 13000 seconds.

 

 

More Information:

MinPresenceSubscriptionExpiry

 

· Stored in the Active Directory as "msRTCSIP-MinPresenceSubscriptionTimeout"

· The default value is 1200 seconds (20 minutes)

· The minimum value for this property is 300 and the maximum value is 86340

MaxPresenceSubscriptionExpiry

 

· Stored in the Active Directory as "msRTCSIP-MaxPresenceSubscriptionTimeout"

· The default value is 43200 seconds (12 hours)

· The minimum value for this property is 300 and the maximum value is 86340

 

 

Workaround:

 

If you are encountering SIP interoperability failures via PIC against Windows Live/MSN Messenger, please modify your msRTCSIP-MaxPresenceSubscriptionTimeout and msRTCSIP-MinPresenceSubscriptionTimeout values (either via ADSIEDIT or LDP) in accordance with their guidance (min: 3600, max: 13000)

 

 

If you have installed OCS into the System container in the Active Directory, these attributes will be stored at the following location:

 

CN=Global Settings,CN=RTC Service,CN=Microsoft,CN=System,DC=yourdomain,DC=com

 

 

If OCS is installed in the Configuration container, you can locate these values in the Active Directory here:

 

CN=Global Settings,CN=RTC Service,CN=Services,CN=Configuration,DC=yourdomain,DC=com

 

Update:

 

If for any reason the above-mentioned values get reset, they will then fall outside of the default values. Consequently, you'll need to modify the msRTCSIP-DefPresenceSubscriptionTimeout value, as without correcting this to be within range, the OCS Front-End service will not start. Additionally, you will find the following error in the Office Communications Server Event Log:

 

Log Name: Office Communications Server
Source: OCS User Services
Date: 8/20/2009 6:30:31 AM
Event ID: 30929
Task Category: (1006)
Level: Error
Keywords: Classic
User: N/A
Computer: ocs.contoso.com
Description:
Failed to process WMI event to update the User Services Global Settings because the value of Attribute1 cannot be greater than the value of Attribute2.

Attribute1: DefPresenceSubscriptionExpiry Attribute2: MaxPresenceSubscriptionExpiry
Cause: This could happen during upgrades, or in topologies with mixed 1.0 and 2.0 servers or if the Active Directory is modified directly.
Resolution:
Use MMC (or WMI) to update all the values that are out of bounds. The changes will take place without restarting the server.
Event Xml:
<Event xmlns="https://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="OCS User Services" />
<EventID Qualifiers="50158">30929</EventID>
<Level>2</Level>
<Task>1006</Task>
<Keywords>0x80000000000000</Keywords>
<TimeCreated SystemTime="2009-08-20T13:30:31.000Z" />
<EventRecordID>26728</EventRecordID>
<Channel>Office Communications Server</Channel>
<Computer>ocs.contoso.com</Computer>
<Security />
</System>
<EventData>
<Data>DefPresenceSubscriptionExpiry</Data>
<Data>MaxPresenceSubscriptionExpiry</Data>
</EventData>
</Event>

 

 

Credit to Jason Groves & Greg Anthony for the msRTCSIP-DefPresenceSubscriptionTimeout piece