Sunday, September 2, 2007

G.732-G.704 Framing Stardard

The International CCITT framing format is adopted by most countries (Europe, Central/South America, etc.). These facilities operate at 2.048 MBPS.

This framing format is actually defined in CCITT Recommendation G.704, although Recommendation G.732 supplements G.704.

G.704: Synchronous Frame Structures
Used and Primary and Secondary
Hierarchical Levels

G.732: Characteristics of Primary PCM
Multiplex Equipment Operating at
2048 KBPS.

G.732-G.704 Framing Stardard
The standard frame is 32 timeslots, with each timeslot consisting of an 8-bit byte. A Multiframe consists of 16 frames, numbered zero to fifteen.

The timeslots are numbered 0 to 31. Timeslot 0 is used for:

- Synchronization
- Alarm Transport
- International Carrier use

Timeslot 16 may be used to transmit Channel Associated Signaling (CAS) information. Note that G.732 DOES NOT define the signaling states, only the transport of the states through the G.732 frame.

However, G.704 recognizes the requirement for Common Channel Signaling and also allows the TRANSPARENT End-To-End transport of Timeslot 16.


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