Topic Last Modified: 2010-07-15
The Client Version Check application provides you with a way to define a set of rules that specify the version of clients that are supported in your Microsoft Communications Server 2010 environment. When two clients of differing versions interact, the features that are available to either client can be limited by the capabilities of the other released client. To make the greatest use of features included in Communications Server 2010 and to improve the overall user experience, you can use the Client Version Check to restrict the client versions that are used in your Communications Server environment.
Client Version Check
When a supported client logs on or is invited to a session, Client Version Check checks the SIP User Agent header to determine the client version. Depending on the version of the client, and the rules that you have configured, the Client Version Check application does one of the following:
- Allows the client to log on to the pool (Allow).
- Allows the client to log on and receive updates from Windows
Server Update Service or Microsoft Update (Allow and
Upgrade). This action is available only when the Office
Communicator (OC) application is selected.
- Allows the client to log on and presents the user with a
message that indicates the user is can upgrade their client. The
message comes with the URL that you specify, and the user can click
on that URL to go to the page represented (Allow with URL)
and upgrade their client.
- Prevents the client from logging on to the pool
- Prevents the client from logging on and allows the client to
receive updates from Windows Server Update Service or Microsoft
Update (Block and Upgrade). This action is available only
when the Office Communicator (OC) application is selected.
- Prevents the client from logging on and presents the user with
a message that indicates the user is using a client that is not
supported. The message comes with the URL that you specify, and the
user can click on that URL to go to the page represented (Block
Each pool maintains a client version control list that you configure. This list contains rules that specify the client versions you want to filter and the appropriate action for each client version. The Client Version Check can act according to a specific client version number. It can also act according to a client version that is less than or equal to or greater than or equal to the version number that you specify. The Client Version Check also includes a configuration option that specifies the default action for clients that are not included in the client version control list.
When you configure the Client Version Check, you specify the way in which clients are handled during logon. The Client Version Check provides options for configuring the following:
- The User Agent header. This is the name of the agent for the
- The identity. This is the scope that the rule should be applied
to. If multiple rules with different levels of scope are triggered,
the scope with the lowest level of granularity is applied. For
example, if a service level rules states that the client should be
blocked, but a user level rule also states that the client should
be allowed, the client will be allowed as a user level rule is the
- The client version number. This includes the major version
number, the minor version number, the build number, and the QFE
number. The number is presented in the following format:
- The matching rules. These specify the comparison operations to
perform to identify the specific version or range of versions of
the client to which the filtering action is to apply.
- The action to take based on client version. Available values
are Allow, Block, Allow with URL, Block
with URL, Allow and Upgrade, and Block and
- The client download URL. This is used only for the Block
with URL and Allow with URL options.
A default list of rules is installed when you install Communications Server 2010. To customize the set up rules for your deployment, you can edit an existing rule, or you can create a new rule. If you do not want to block earlier version of the client, you will need to modify this list.
|The default list of rules automatically blocks earlier versions of Microsoft Communicator and Microsoft Communicator Phone Edition that try to connect to Communications Server 2010. If you would like to change this behavior, you can create a new rule to allow earlier clients to connect to the Communications Server 2010 server and then add this to the top of the list. Although you can also edit the default the default rules to allow earlier clients to connect, we do not recommend this approach.|
|The rules are listed in their order of precedence. For example, if you have a rule that allows Communicator clients with a version 1.5 or later to connect, followed by a rule blocking clients earlier than version 2.0, the first rule will match and thus takes precedence; Communicator 1.5 clients can connect|
Client version checks in the version control list act on specific criteria. However, you also need to configure a default rule to apply to clients that do not match any other client version rule, specifying one of the following: Allow, Block, or Block with URL.