Learn about the G.709 protocol

Optical transport networks rely on SONET/SDH protocols to transport bits. These core networks, which originally carried mostly voice traffic, now carry more data bits than digitized voice bits. Switches at a core network's edges must now combine data and digitized voice bits so both will reliably traverse the core network and arrive intact at their destinations. A new protocol, ITU-T G.709, merges voice and data for transport over core networks at speeds from 2.5 Gbits/s to 40 Gbits/s (Ref. 1).

Optical networks can use the G.709 protocol to merge data and digitized voice for transport.

G.709 defines frames that include numerous header bits that provide supervisory functions and condition the signal for transport between optical channel termination points. G.709 adds about a 7% overhead to the SONET/SDH signal, but it improves transmission quality on long transmission lines. To learn the details of the G.709 protocol, you can download a paper written by Guylain Barlow, product manager at Innocor (Almonte, ON), at www.tmworld.com/G709.