The architectural mode of the Protection group. This can either be 1+1, 1:1, 1:n. 1+1 In the 1+1 protection scheme, a fully dedicated protection entity is allocated. Data traffic is copied and fed at the source to both the working and the protection entities. The traffic on the working and the protection entities is transmitted simultaneously to the sink of the protection domain, where selection between the working and protection entities is performed 1:1 In the 1:1 scheme, a protection path is allocated to protect against a defect, failure, or a degradation in a working path. In normal conditions, data traffic is transmitted over the working entity, while the protection entity functions in the idle state. If there is a defect on the working entity or a specific administrative request, traffic is switched to the protection entity. 1:n In case of 1:n linear protection, one protection entity is allocated to protect n working entities. The protection entity might not have sufficient resources to protect all the working entities that may be affected by fault conditions at a specific time. In this case, in order to guaranteed protection, the protection entity should support enough capacity and bandwidth to protect any of the n working entities.