VT group optical extension interface and VT group optical extension format method

Abstract

A VT group optical extension format (FIGS. 7 and 8) defines a transport frame for the transfer of 135 bytes, each byte comprising 8 bits, the format providing a line rate of 8.640 Mbit/S. Each frame comprises a transport overhead portion and a payload portion. The transport overhead portion is comprised of 27 bytes and defines various operations, administration and maintenance functions, whereas the payload portion is comprised of 108 bytes which directly correspond to one VT group of an STS-N frame (FIG. 1). The VT group optical extension format line rate is determined as an integer multiple (i) of an STS-N network element clock where i is 6 if N is 1 and i is 18 if N is 3. An optical extension interface (172) is provided between a VTG bus (140) and an optical extension (178), the interface (172) being responsive to the provision of a multiplexed VT group payload provided on the VTG bus (140) for providing a corresponding VT group optical extension transport frame on the optical extension (178), the interface (172) being further responsive to the provision of a VT group optical extension transport frame on the optical extension (178) for providing a multiplexed VT group payload and associated path overhead to the VTG bus(140).

Dependencies are inferred from the claim text.