Patent ID: 8036147

Claim:
A method for bidirectional exchange of Link Capacity Adjustment Scheme (LCAS) control information for controlling a virtual concatenated group (VCG) binary stream transmitted between a first network element and a second network element via a bi-directional optical communication line interconnecting said two network elements, while said VCG binary stream forms substantially unidirectional data traffic transmitted in a first direction via said bi-directional optical communication line, with none or negligible data traffic transmitted in a second direction opposite to said first direction; the method comprising the following arrangement for exchanging the LCAS control information: a) in the first direction, transmitting said LCAS control information via said bi-directional optical communication line in said VCG binary stream, by placing the LCAS control information in one or more overhead bytes conventionally specified for said VCG binary stream, b) in the second direction, transmitting said LCAS control information by placing it in one or more overhead bytes of an existing binary stream passing, in said second direction, via a communication trail connecting said first network element and said second network element, wherein said existing binary stream has no relation to said VCG binary stream to be controlled by said LCAS control information, and is not provisioned specifically for transmitting said LCAS control information; wherein the communication trail is an additional communication trail connecting the first network element and the second network element, not forming part of said bi-directional communication line; and wherein said overhead bytes in the existing binary stream are the conventionally specified bytes of the existing binary stream being a binary stream not forming a member of any VCG.