# How maintenance works
<a name="how-maintenance-works"></a>

For router I/Os, MediaConnect automatically schedules maintenance every 60–66 days after the I/O is started. You configure a preferred day and start hour, and MediaConnect applies updates to the I/O within that two-hour window.

For flows, MediaConnect assigns a "Required by" date when updates are available. You configure a preferred day and start hour, and MediaConnect restarts the flow within that two-hour window.

**What happens during maintenance**  
The impact of maintenance depends on the resource type:

Router outputs  
The output enters the **Migrating** state. During this process, there is an interruption to that output's stream only. After the maintenance completes, the output returns to the **Active** state.

Router inputs  
The input enters the **Migrating** state. During this process, there is an interruption to all outputs currently routed to receive from that input. After the maintenance completes, the input returns to the **Active** state.

Flows  
During maintenance, there is an interruption to all outputs on the flow. 

**If maintenance does not complete**  
The rescheduling behavior depends on the resource type:

Flows  
If MediaConnect is unable to perform maintenance at the scheduled time, the service reschedules maintenance to the following week's maintenance window.

Router I/Os  
If maintenance does not complete within the scheduled window, MediaConnect reschedules it to the next maintenance period.