Lub G.703 (Co-Directional G.703) interface faib 64Kbps voj voog mus rau 4 chav nyob ib ntus, nws siv "0101" sawv cev "0", "1100" sawv cev "1".Los ntawm alternating transformation polarity ntawm lub block uas nyob ib sab, binary signals hloov peb theem teeb liab.