iRule to increase tcp timeout for given client

Hi,

I need to increase a tcp timeout value. when a certain client connects to VIP. I did this:

when CLIENT_ACCEPTED {
 if { [IP::addr [IP::client_addr] equals 10.10.10.10] } {
    TCP::idletime 600
 }
}

But it resulted in an error:

"increase_idle_timeout:3: error: [undefined procedure: TCP::idletime][TCP::idletime 600]"

On the other hand this was accepted:

when CLIENT_ACCEPTED {
 if { [IP::addr [IP::client_addr] equals 10.10.10.10] } {
    IP::idle_timeout 600
 }
}

What is the difference between IP::idle_timeout and TCP::idletime?

I'm running 11.5.7