Adding an SMS Channel allows you to create a ticket and enable an SMS chat between you and the contact for the company. 

** IMPORTANT NOTE ** The system will use the ticketing defaults that are setup for that SMS Channel so that you don't have to select them each time. This allows you to generate tickets more quickly with less selections. 

To enable an SMS Channel go to Messaging -> SMS Channels

Click Add at the top right

Once you click Add then select the Company, Contact and a template or manually type in your subject and message. You can also create templates and use those for faster ticket creation.