A method and Bridge in a Provider Backbone Bridge Network (PBBN) for enabling frames from a Higher Layer Entity attached alternatively to a Provider Instance Port (PIP) on an I-Component of a Backbone Edge Bridge or to a Customer Backbone Port on a B-Component of the Backbone Edge Bridge, to reach an intended entity in the PBBN. A Virtual Instance Port Service Access Point (VIP SAP) is configured for every VIP and every Higher Layer Entity configured on the I-Component. An Enhanced VIP Port Connectivity function utilizes the VIP SAP to tunnel customer-initiated Layer 2 Control Protocols (L2CPs). A Special Multiplexed SAP handles the frames of the Higher Layer Entity, and is assigned an I-SID value that is universally recognized to identify the L2CPs. A Service Instance Multiplex Entity utilizes the Special Multiplexed SAP to transfer frames between the PIP or the Customer Backbone Port and the entity inside the PBBN.