This article describes new features introduced in Microsoft Lync Server 2013 Preview, Persistent Chat Server. It also compares some of these features with the earlier features in Microsoft Lync Server 2010, Group Chat.

Microsoft Lync Server 2013 Preview, Persistent Chat Server features provide the following:

  • An administrative experience in Lync Server Control Panel and elimination of the Group Chat Admin Tool.
  • Integration of configuration settings for Persistent Chat Server into Topology Builder by eliminating the Group Chat Configuration tool.
  • Easy migration and upgrade from previous versions of Persistent Chat Server.
  • High availability and disaster recovery solutions.

For in-depth about Persistent Chat Server see Planning for Persistent Chat Server in the Lync Server 2013, Technical Library. 

Author: Jack Wight, Senior Technical Writer

Publication date: August 28, 2012

Product version: Lync Server 2013 Preview

New Persistent Chat Server Features

Lync Server 2013 Preview, Persistent Chat Server enables you to participate in multiparty, topic-based conversations that persist over time. Lync Server 2013 Preview, Persistent Chat Server can help your organization do the following:

  • Improve communication between geographically dispersed and cross-functional teams.
  • Broaden information awareness and participation.
  • Improve communication with your extended organization.
  • Reduce information overload.
  • Improve information awareness.
  • Increase dispersion of important knowledge and information.

Key Topology Changes for Persistent Chat Server

 Lync Server 2013 Preview, Persistent Chat Server includes the following high-level changes:

  • Persistent Chat Server is now a server role. In Lync Server 2010, Group Chat Server was a third-party trusted application for Lync Server 2010. In Lync Server 2013 Preview, Persistent Chat Server functionality is implemented using three new server roles:
  • PersistentChatService: Main Persistent Chat Server services implemented as a Front End Server role.
  • PersistentChatStore: Back End Server role.
  • PersistentChatComplianceStore: Back End Server role for persistent chat Compliance.

These Persistent Chat Server roles are optional, and installed only by customers who want comprehensive Persistent Chat Server functionality.

  • The Persistent Chat Server Front End Server role runs on a computer not collocated on the Lync Server Front End Server, and runs two services:
  • Persistent Chat service
  • Compliance service

In Lync Server 2013 Preview, Persistent Chat Server, the File Upload/Download web service is now collocated with the Lync Server 2013 Preview, Front End Server. As a side effect, Internet Information Services (IIS) is no longer a prerequisite for Persistent Chat Server.

Running these services on each Persistent Chat Server Front End Server provides high availability for these services in a multi-server Persistent Chat Server pool.

  • In Persistent Chat Server, Lookup service has been eliminated. In Lync Server 2010, Group Chat, the Lookup service ran on every Group Chat Server, Front End Server, and performed routing to one of the Channel Servers. The Lookup service simulated an imaginary user with multiple points of presence. The endpoint that accepted the invitation then provided load balancing to the right Channel Server based on the load across the Channel Servers. Lync Server 2013 Preview relies on routing using contact objects, wherein each Persistent Chat Server pool is represented by a contact object that is used by the Lync Server 2013 Preview, Front End Servers to identify and route to a Persistent Chat Server pool, and one of the computers running Persistent Chat Server in the pool.
  • In Lync Server 2013 Preview, there are Compliance service modifications. In Lync Server 2010, the Compliance service ran standalone (non-collocated), on a single server. The Compliance service now runs on all the Persistent Chat Server, Front End Servers, alongside the Persistent Chat service, and thereby provides high availability in a multi-server Persistent Chat Server pool.

The Message Queuing (also known as MSMQ) queue, shared by the Compliance service and the Persistent Chat service on each Persistent Chat Server, Front End Server, is now a private queue shared only by the two services. All compliance services write to the same Compliance Back End database. All compliance services also read from that database for the purposes of sending the data to their instance of the adapter. The Compliance Back End Server is represented as a new Back End Server role.

Important. As in previous versions, all compliance data is processed only once. In Lync Server 2013 Preview, Persistent Chat Server, any one of the adapter instances could process the data.

Persistent Chat Server high availability improvements. SQL Server mirroring is used to provide high availability for the Persistent Chat Server content database and persistent chat compliance database within a datacenter (in-site).

Persistent Chat Server disaster recovery improvements. Persistent Chat Server supports a stretched pool architecture that enables a single Persistent Chat Server pool to be stretched across two sites. SQL Server Log Shipping is used for cross-site disaster recovery.

User Roles in Persistent Chat Server

Persistent Chat Server provides for the concept of Allowed/Denied members. They apply to persistent chat categories, and control what roles can be used in a particular category and its nested chat rooms.

Important. An Allowed/Denied member is not the same as Member role.

The concept of an Allowed/Denied member list is not visible within Persistent Chat Server, with one exception. (See following Important note.) It simply defines a set of users from which you can choose assigned roles. For example, if a list contains Contoso domain, you can be given a role of manager to a chat room under that category or the chat room itself. If that same list contains just Contoso developers, you cannot generate a role in that category or its nested chat rooms.

Important. Searches display all open, closed, and secret chat rooms for which the user performing the search is an Allowed/Denied member. Accordingly, search results remove visibility to all chat rooms for which the user performing the search is not in the Allowed/Denied member list of the parent category.

The primary factor for this concept is ethical walls. For example, an administrator can create chat rooms in a category for traders only, whereas chat rooms in another category can be used by analysts only. After the categories and allowed members are set up, further administrative actions cannot break that rule, unless that rule is changed.

The following four user roles exist in Persistent Chat Server:

Creator: Users who have permissions to create chat rooms. These users are in the Creators list of certain categories for chat rooms, meaning they can create chat rooms of that category, and can further assign membership according to the category, and assign managers to manage the chat room. A Creator is always added as a manager to the chat room it creates by the server.

Note. A Creator simply provides rights for creating chat rooms. It is the automatic promotion to Manager that enables the Creator to further refine memberships, managers, and so on, on the created chat services.

This role exists because you might want to centrally manage creating chat rooms to enforce policies/conventions, and subsequently delegate the chat room management to other users in the organization.

Manager: Users who manage properties of a chat room. Chat room managers can modify the member list (add and remove members), modify the chat room managers list (add and remove managers), and participate with members and presenters if added to those roles. Chat room managers can disable chat rooms and can change all properties of the chat room, except change the category of the chat room. Only the Persistent Chat administrator can change this after the chat room has been created.

Member: Users who are members of a chat room. These users can see the chat rooms in the directory (even if the chat room is secret), as well as subscribe to the chat room (metadata such as unread messages, ego filters, and keyword filters) and participate in the chat room (post, get content, and search). Users who aren’t members of the chat room, can search for the chat room, but need to request access to join these chat rooms to access content. (There is no request access or approvals built into the system; these are done externally by email, phone, or other contact.)

Presenter: Users who can post to an auditorium room.

The following roles are global Lync role-based access control (RBAC) roles:

Persistent chat administrator (CsPersistentChatAdministrator): User designated as CsPersistentChatAdministrator to administer persistent chat using Windows PowerShell command-line interface cmdlets remotely. Persistent chat checks that the persistent chat administrator is member of RTC Local administrator local group on the server running persistent chat.

The CsPersistentChatAdministrator role can manage chat rooms (modify all properties including membership, managers, categories), as well as create and manage chat room categories that define who can create what kind of chat rooms in Persistent Chat Server. Administrators can also mark chat rooms as disabled and clean up chat rooms that are no longer active. Administrators are not subject to the Creators or Allowed Members restrictions. Administrators can create any kind of chat room and add themselves as a member to any chat room.

Lync Administrator: Overall enterprise administrator for Lync Server 2013 Preview responsible for deployment.

Operations Manager: User responsible for managing day-to-day operations.

Third-party developers and partners: Third-party developers extend the system, in particular providing an ethical wall solution for group conversations, compliance support and tools, web/mobile clients, and a framework for BOT development.

What’s different about user roles from previous Group Chat Server versions?

Lync Server 2010, Group Chat had a user administrator, a chat room administrator role and a Lync Server administrator role that could manage add-ins. Persistent Chat Server is simply providing a persistent chat administrator role who can manage chat rooms, add-ins, and categories (and therefore, user access for those categories). Now the persistent chat administrators are role-based access control (RBAC) roles, matching the other types of Lync administrators.

What’s different about chat room categories from previous Group Chat Server versions?

The chat room category now has a constrained hierarchy in Lync Server 2013 Preview, Persistent Chat Server, (for example, no more nesting, and so forth). The Allowed Members property comes closest to the concept of a scope.

A persistent chat administrator in Lync Server 2013 Preview has the ability to create and manage chat room categories. As part of creating and managing chat room categories, the persistent chat administrator can configure principals (Active Directory groups/containers/users) that have access to be members/creators of chat rooms of a particular category. A persistent chat administrator can also add DeniedMembers to a category and these become explicit exclusions to the allowed list. DeniedMembers override what’s in AllowedMembers.

What’s different about chat room properties from previous Group Chat Server versions?

Lync Server 2013 Preview, Persistent Chat Server introduces open chat rooms. All allowed members can join the chat room without exclusive membership.

The following chat room properties, which were in previous versions of Persistent Chat Server, have been eliminated:

  • Topic
  • Create New Member list: In Persistent Chat Server, all chat rooms start with empty membership (and can maximize to a membership equaling the Allowed Members).
  • File Upload: Used to be for a chat room, but is now only associated with a category.
  • Chat History: Used to be for chat room, but is now only associated with a category.
  • Invites: A room setting can no longer override the parent category.

What’s different about policies from previous Group Chat Server versions?

Persistent Chat Server has a new persistent chat Enabled Lync policy, per user/pool/site/global settings.

Previous versions of Group Chat Server did not have any policies integrated into Lync Server policies. On a per user and per category/room basis using the Can Upload Files per user feature, you could make the user a User administrator, a chat room administrator, or configure the user’s ability to upload files. The Persistent Chat Server File Upload feature is just per category.

Logging

Logging for Persistent Chat Server and Microsoft System Center Operations Manager are integrated into the Lync Server 2013 Preview trace logging.

Additional Resources

Lync Server 2013 Preview Articles

Lync Server Resources

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Keywords: Persistent Chat Server, Group Chat Server, Topology Builder, server roles, compliance, File Upload/Download web service, HADR, user roles, logging