Extending Persistent Chat on Mobile Devices

Currently Skype for business persistent Chat is not supported on mobile devices by default. Only the Lync and Skype for Business  desktop client supports Persistent Chat.

To extend this feature on mobile devices we need to bring an additional component software from MindLink. Mind Link Software is a Microsoft Gold Partner who is offering support for Persistent Group Chat on mobile devices (iOS, Android and BlackBerry). Mind-link are the only developer available at the moment who would be able to fill the gap and extending this functionality to the mobile devices.

In this article we will have a look at configuring MindLink software for Persistent chat feature on mobile

You can download the evaluation version from the below Link


Basically  they have 3 servers in their architecture which are having different roles if we consider as a whole package.

1) Mind Link Anywhere server – Can be used for Having corporate Persistent chat feature on the Web(like Whats-app web) and integrating SharePoint sites with the chat services.

E.g. below for Mind Link Anywhere :

Having persistent chat on the web



Having this chat feature enabled on the SharePoint sites


2) MindLink Integration server – Used for integrating social  News Feed and  social twitter feed.

3) MindLink Mobile Server – Used for integrating with our persistent chat pool.

So we require only one server at this point to extend persistent chat functionality to the mobile devices.So now lets look into the steps to extend the persistent chat functionality alone  on the mobile devices since we are focusing only on them in this blog.

Hardware Requirements:

Each host machine should meet the following minimum requirements:

  • Dual or Quad core, 64-bit CPU (Minimum 2.4GHz)
  • 4GB RAM
  • Gigabit Ethernet connection
  • 1Gb disk space (80Mb for installation of binaries and up to 1Gb for Preferences to support over 1000 users)
  • Additional Disk Space may be required for storing log files, minimum of 100MB
  • Windows Server 2008 R2, 2012, or 2012 R2

Readiness for the persistent chat integration:

  • A trusted application pool needs to be created between your Lync/SFB server and the MindLink server FQDN or pool FQDN if its multiple servers based on the environment.
  • An URL must be decided for the MindLink server to publish them externally so that users can access them from mobile devices for persistent chat.
  • An SSL certificate must be purchased for the external URL for secure communication.
  • An internal certificate from Trusted CA must be placed in the MindLink server to trust this application pool.
  • Apple device APN’s certificate must be placed on the MindLink server for Apple devices push notifications and revocation check.

Ports and protocol requirements :

  • Port 7072 for socket server needs to be opened
  • Port 7074 for web service needs to be opened
  • Port 7073 for file service needs to be opened
  • APN port 2195 for gateway.push.apple.com needs to be opened


Overall the Architecture of the MindLink provision should look like below



Installation :

The installation of the software is very simple. All you need to do is download and install the Mindlink mobile on the new server . MindLink uses REST API. It integrates data from existing Lync servers and persistent chat groups through the trusted application pool.
This allows users to access and discuss information within the right context.
MindLink API provides a straight forward web services layer that simplifies the publishing and dependency on .net platform.

Make sure that you have the local trusted CA, Public SSL for the url published and the apple device APN’s placed on that server in the local computer account.

After this is done we just need to enter the url in the location , import the license file from Mind Link support and start the Mind Link service.

After this what happens is that when a user logs in from the mobile client it reaches the MindLink server. It identifies a trusted application created between the MLM and Lync. Post verification of the user account it provides successful authentication.

You might face some challenges in these customized non standard ports on the firewall to the internet and to the server apart from that rest all would be smooth.

An example below of entering the external host name

Note: Only the first hostname URL is mandatory and rest all are optional. Enter the URL name here that will be publishing outside.



This is an example for apple device connection settings


MindLink Mobile App Experience

After successful configuration we just need to enter the URL that has been published externally for this service


After successful login users will have the below option

They can see live streaming of the persistent chat groups where they are member of

They can send and receive  messages in the persistent chat

They can search for persistent chat groups

They can search and IM individuals

Users can receive IM notifications even if they are not logged in to their Lync/SFB mobile client

Users can search for persistent chat messages, hashtag and mention option is also there.

Visible Persistent Chat Groups


Able to change the IM and Presence


Live streaming of the persistent chat can be seen


Overall Features & Limitations:

  • Its a secure Enterprise Group Chat compatible with Microsoft Lync & Skype for Business.
  • IM Presence can be updated.
  • They cannot participate in audio and video calls from this application.
  • Currently users have the ability to open files which are sent from Lync desktop.
  • File Transfer and sharing from the application is not available at the moment.However an option to insert a weblink option in the chat is available.
  • Custom Ports for the application to be accessed from externally is little bit difficult. Its not possible to change them to the default ports since the application API is configured to bind and listen on these ports 7072,7073 & 7074 only.


Sathish Veerapandian

MVP – Office Server & Services


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