This supplement expands the range of sub STS-1 interfaces to include payloads that are multiples of the VT Group. Specifically, sub STS-1 payloads of N x VT Group shall be allowed with N = 1-5 inclusive. The same single column of Line overhead is used regardless of the value of N that is used.

ATIS T1.105.07a-1997 (R2008)
Original price was: $182.00.$91.00Current price is: $91.00.
Synchronous Optical Network (SONET) – Sub STS-1 Interface Rates and Formats Specifications (inclusion of N x VT Group Interfaces)
The Alliance for Telecommunications Industry Solutions , 12/01/1997