Provide functionality in Customer Portal to escalate an issue

We would like to have to escalation functionality in the JIRA Service Desk Customer Portal. This functionality should include:

• Steps in the workflow that are transitioned to automatically when the issue is escalated.
• Allow to setup escalation resource, so the ticket can be assigned to a different Agent behind the scenes. This is transparent to the customer.
• Change the priority of the issue to one suited for escalation levels of urgency.