What is G.703?
G.703 is a standard for transmission over digital carriers, typically T1 and E1 links. The standard was created by the CCITT and uses pulse code modulation to encode speech data. It uses either balanced twisted pair or unbalanced coaxial cable, with balanced service being more common around the world.
G.703 uses pulse code modulation with bit rates between 64 Kbps and 2.048 Mbps. The standard is mainly used to connect bridges, routers, multiplexers and other network devices. G.703 uses either a balanced 120 ohm twisted pair cable or an unbalanced 75 ohm coaxial cable.
Balanced service is most common worldwide, but unbalanced service is more common in the UK and the Netherlands. The EEC Open Network Provision standard is intended to provide a balanced service across Europe.