Hi, I have a couple of 3524xl switches and their memory usage is always at or above 70% and a 2924xl switch that is always at 90%. Is this common for switches to perform like this? Is it time to upgrade these switches?

Here is my predicament. When a number is bad, the cell phone user travled outside their coverage area, etc, I sometimes do not get back a message from the far-end switch. I would like to generate my own messages instead of relying on the end-points ...