G.703 is a
ITU-T
The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) is one of the three Sectors (branches) of the International Telecommunication Union (ITU). It is responsible for coordinating Standardization, standards fo ...
standard originally written in 1972 but subsequently revised a number of times since. It defines a physical and electrical interface used for encoding voice or data over 75
ohm co-axial cable terminated in
BNC or Type 43 connectors or 120
ohm twisted pair cables terminated in
RJ48C jacks. The choice is carrier- and region-dependent.
G.703 defines digital carriers of various speeds such as
T1 and
E1. These are organised as part of a hierarchy of carriers defined in G.702.
A G.703 E1 link is typically, though not necessarily, framed using the G.704 standard which divides the data stream into time slots. Typically, each time slots represents an E0 (64 kbit/s) voice channel encoded using
pulse-code modulation
Pulse-code modulation (PCM) is a method used to digitally represent analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitud ...
(PCM). The PCM coding is defined in the
G.711 standard. G.704 also includes a control timeslot slot and a signalling timeslot (CAS or CCS).
References
External links
G.703 at searchNetworking.comG.703 on Network EncyclopediaPhysical/electrical characteristics of hierarchical digital interfaces REC-G.703/ at ITU.INT
ITU-T recommendations
ITU-T G Series Recommendations
Telecommunications-related introductions in 2016
{{telecomm-stub