[This is pre-release documentation and subject to change in future releases. This topic's current status is: Milestone-Ready]

Topic Last Modified: 2010-07-18

This topic discusses the ability of Microsoft Communications Server 2010 clients to coexist and interact with clients from earlier versions of Communications Server.

There are two types of client compatibility, as follows:

Multiple points of presence (MPOP): the ability of a single user to sign in to a server with multiple clients and multiple client versions
Interoperability: the ability to interact with another user who is signed in using a different client type, or an earlier version of the same client

Planning for Compatibility

Important:
In order to fully test the new Communications Server 2010 features during migration, you must ensure that previous client versions have the most recent updates, or hotfixes, installed. See Planning for Client Migration for details.

Communications Server 2010 fully supports interoperability among Communications Server 2010 clients.

Most IM, presence, and existing voice features are also supported when interacting with Microsoft Office Communications Server 2007 R2 and Microsoft Office Communications Server 2007 clients. See "Communications Server “14” Interoperability with Previous Client Versions" later in this topic for details.

For best results with online meetings, see Migration Considerations for Online Meetings.

Compatibility among Communications Server 2010 Clients

All Communications Server 2010 clients can interoperate with other Communications Server 2010 clients.

Most Communications Server 2010 clients also support the multiple points of presence scenario—that is, a single user can be signed in at multiple locations—with the following exception:

Microsoft Communications Server 2010 Attendant users can only be signed in simultaneously with phones running Microsoft Communicator “14” Phone Edition. Simultaneous sign-in with other Communications Server 2010 clients is not supported.

Multiple Points of Presence (MPOP) with Previous Client Versions

The following table describes the client versions that are supported when a single user is signed in to Communications Server 2010 at multiple locations.

Note:
Communications Server 2010 clients cannot sign in to previous server versions.

Current Client Version	Planned Client Version MPOP Support (with required updates)
Communicator "14" Communicator “14” Attendee	Microsoft Office Communicator 2007 R2 Microsoft Office Communicator 2007 2007 release of Microsoft Office Communicator Web Access 2007 R2 release of Microsoft Office Communicator Web Access Phones running Microsoft Office Communicator 2007 R2 Phone Edition Phones running Microsoft Office Communicator 2007 Phone Edition Microsoft Messenger for Mac 7
Communications Server 2010 Attendant	Phones running Microsoft Communicator “14” Phone Edition
Phones running Communicator “14” Phone Edition	Office Communicator 2007 R2 Office Communicator 2007 Messenger for Mac 7
2007 R2 release of Microsoft Office Communicator Mobile	Office Communicator 2007 R2 Office Communicator 2007 Office Communicator 2007 R2 Phone Edition Office Communicator 2007 Phone Edition Messenger for Mac 7

Note:
Messenger for Mac 7 supported features are described in the Microsoft Messenger for Mac 7 Deployment Guide: http://go.microsoft.com/fwlink/?LinkId=177909

Communications Server 2010 Interoperability with Previous Client Versions

This section discusses Communications Server 2010 interoperability support for clients shipped with the last two Communications Server versions-Office Communications Server 2007 R2 and Office Communications Server 2007.

Note:
Communicator Web Access and Microsoft Office Live Meeting 2007 cannot be used to join new online meetings scheduled on Communications Server 2010. Communicator "14", Microsoft Communicator “14” Attendee, and Communicator Web App are the recommended alternatives. See Migration Considerations for Online Meetings for details.

IM, Presence, Voice, and Video Interoperability

The following table describes the availability of these features during migration.

Table: IM, Presence, and Voice Interoperability with Previous Client Versions

	Office Communications Server 2007 Clients	Office Communications Server 2007 R2 Clients	Communications Server 2010 Clients
Communications Server 2010 Clients	IM, presence, and video supported; some voice feature limitations (see below)	IM, presence, voice, and video supported	IM, presence, voice, and video supported

Interaction with Microsoft Office Communicator 2005 clients (basic presence and IM) is supported only if the Office Communicator 2005 user is on a federated network.

Note:
Call Park Service and Response Group Service require that you deploy Communications Server 2010 Edge Server and Director roles.

Voice Interoperability Considerations During Beta

Voice interoperability issues to be aware of during beta are as follows:

Communicator 2007 does not support voice features added in Communicator 2007 R2 and Communicator "14", such as call park, team call, and response group service.
Call park issues you should be aware of during migration are as follows:
- A call parked by a Communicator "14" user cannot be unparked by clients or devices signed in to an earlier version of Communications Server.
- You cannot park a call to a Communications Server 2007 client or device.

Conferencing Interoperability Considerations During Beta

When a user account is moved from Communications Server 2007 R2 to a Communications Server 2010 server, the following information moves along with the user account:

Meetings already scheduled by the user.
The user’s PIN (there is no need for new PIN assignment).

The following information does not move to the new server:

Meeting content. You should advise meeting organizers to reload content into their scheduled meetings after migration.

The following tables describe two conferencing interoperability scenarios:

Previous client version interoperability with Communications Server 2010 online meetings
Communicator "14" interoperability with meetings hosted or scheduled on previous server versions

Table: Previous Client Versions and Communications Server 2010 Online Meetings

Communicator 2007 and Communicator 2007 R2 Interoperability	Schedule Communications Server 2010 Online Meetings	Join Communications Server 2010 Online Meetings	Behavior in Communications Server 2010 Online Meetings
Before user is moved to Communications Server 2010	Not supported.	Supported if enabled. See Migration Considerations for Online Meetings for details.	No access to new collaboration features unless meeting is escalated to use Communicator Web App. No access to new lobby management features.
After user is moved to Communications Server 2010, but before new clients are installed	Continue using the Conferencing Add-in for Microsoft Office Outlook to schedule conference calls and Live Meeting web conferences.	Supported if enabled. See Migration Considerations for Online Meetings for details.	No access to new collaboration features unless meeting is escalated to use Communications Server 2010. No access to new lobby management features.

Communicator 2007 and Communicator 2007 R2 Interoperability

Schedule Communications Server 2010 Online Meetings

Join Communications Server 2010 Online Meetings

Behavior in Communications Server 2010 Online Meetings

Before user is moved to Communications Server 2010

Not supported.

Supported if enabled. See Migration Considerations for Online Meetings for details.

No access to new collaboration features unless meeting is escalated to use Communicator Web App.

No access to new lobby management features.

After user is moved to Communications Server 2010, but before new clients are installed

Continue using the Conferencing Add-in for Microsoft Office Outlook to schedule conference calls and Live Meeting web conferences.

Supported if enabled. See Migration Considerations for Online Meetings for details.

No access to new collaboration features unless meeting is escalated to use Communications Server 2010.

No access to new lobby management features.

See Migration Considerations for Online Meetings for details.

Table: Communicator “14” Interoperability With Meetings Hosted or Scheduled on Previous Server Versions

Communicator “14” Interoperability With Meetings on Previous Server Versions	Communicator “14” User Experience
Scheduling	Communicator "14" users cannot schedule meetings on earlier server versions. When modifying the end date, subject, or attendee list of meetings migrated from previous server versions to Communications Server 2010, users are prompted to convert the meeting to Communications Server 2010.
Joining	No issues.
In meeting	New Communicator "14" features are unavailable.

Communicator “14” Interoperability With Meetings on Previous Server Versions

Communicator “14” User Experience

Scheduling

Communicator "14" users cannot schedule meetings on earlier server versions.

When modifying the end date, subject, or attendee list of meetings migrated from previous server versions to Communications Server 2010, users are prompted to convert the meeting to Communications Server 2010.

Joining

No issues.

In meeting

New Communicator "14" features are unavailable.

Manager/Delegate Interoperability

For the manager/delegate scenario, both manager and delegate must be using Communicator "14".

Interoperability with Existing Custom Applications

For the purposes of this discussion an existing custom application is defined as follows:

The application uses the Microsoft Office Communicator Automation API or the Microsoft Unified Communications Client API.
The application runs in a migration environment, on a machine where either Communicator 2007 R2 or Communicator 2007 is connected to a Communications Server 2010 server.

Existing custom applications can sign in to a Communications Server 2010 server and interact with Communications Server 2010 clients. However, the following limitations apply:

Existing custom applications do not have access to Communicator "14" features.
Running a Unified Communications Client API custom application on the same machine as Communicator "14" is not recommended.
If your organization plans to enable enhanced presence privacy mode (see Communicator 2010 New Features), Unified Communications Client API custom applications may need to be rewritten. See Client Planning Overview and the Microsoft Communicator "14" SDK for more information.