Complex sentence: Separating the signaling from the data (if a bit-transparent connection is desired), is usually solved by escaping the control instructions, but occasionally the network is designed so that data is (to a varying degree) garbled by the signaling.
Split into simpler sentences: Separating the signaling from the data (if a bit-transparent connection is desired) is usually done by escaping the control instructions. Occasionally, however, networks are designed so that data is (to a varying degree) garbled by the signaling.