No reversal — keep waiting for connection (2,4)
I believe the answer is:
on hold
'waiting for connection' is the definition.
(I've seen this before)
'no reversal keep' is the wordplay.
'reversal' is a reversal indicator.
'keep' becomes 'hold' (both can mean to have or possess something).
'no' reversed gives 'on'.
'on'+'hold'='ON HOLD'
(Other definitions for on hold that I've seen before include "waiting to come in" , "not through yet?" , "Made to wait (on phone)" , "Delayed -- postponed" , "In abeyance" .)