I've recently been tasked with optimizing our phone network, even though I'm purely a security guy.  One of the things users complain about is that if they are on a call and nobody speaks for about 30 seconds, the phone will disconnect.

I assume this is done on purpose in some setting to prevent the phones from taking up bandwidth, etc.  However, I need to either abolish it entirely or change it to a more reasonable number, perhaps 90 seconds instead of 30.  Our setup is as follows:

1)  A Cisco MCS 7800
2)  Cisco Unified CM Administration v. 6.1.4.1000-10
3)  The people experiencing this problem are all using softphones of some form

I've wandered around in the GUI for quite some time trying to find the solution, but it's not jumping out at me.  Attempts to do online searches for this problem have yielded no fruit, as the keywords necessary draw up other topics.

Anyone know how to do this?