Control frame handling by a provider backbone bridge

Abstract

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 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 Provider Instance Port or the Customer Backbone Port and the entity inside the PBBN.

What is claimed is: 
     
         1 . A method of handling control frames in a Provider Backbone Bridge in a Provider Backbone Bridge Network (PBBN), said method 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, said method comprising the steps of:
 configuring a Multiplexed Service Access Point (SAP) of a Service Instance Multiplex Entity for the frames of the Higher Layer Entity, said Multiplexed SAP having a Service Instance ID (I-SID) value that identifies Layer 2 Control Protocols (L2CPs); and   utilizing the Service Instance Multiplex Entity to transfer frames of L2CPs between the PIP or the Customer Backbone Port and the intended entity in the PBBN.   
     
     
         2 . The method as recited in  claim 1 , further comprising the steps of:
 configuring a Virtual Instance Port Service Access Point (VIP SAP) for every VIP and every Higher Layer Entity configured on the I-Component; and   utilizing the VIP SAP to tunnel customer-initiated L2CPs.   
     
     
         3 . The method as recited in  claim 2 , wherein the step of utilizing the VIP SAP to tunnel customer-initiated L2CPs includes the steps of:
 encapsulating the frames of the Higher Layer Entity that are initiated by the PIP and are required to reach Customer Networks placed on an opposite side of the PBBN; and   providing multiple copies of each frame destined to the VIP, wherein one copy is provided for the Enhanced Internal Sublayer Service (EISS) provided by each Bridge Port, and one copy is provided for each Higher Layer Entity attached to the VIP.   
     
     
         4 . The method as recited in  claim 3 , wherein the step of utilizing the VIP SAP to tunnel customer-initiated L2CPs also includes the steps of:
 receiving by an Enhanced VIP Port Connectivity function, an Indication from a VIP EISS access point for the PIP; and   in response to the Indication, providing by the Enhanced VIP Port Connectivity function, a corresponding Indication with identical parameters at a VIP EISS supporting a MAC Relay Entity and the VIP SAP supporting the Higher Layer Entity.   
     
     
         5 . The method as recited in  claim 4 , wherein the step of utilizing the VIP SAP to tunnel customer-initiated L2CPs also includes the steps of:
 receiving by the Enhanced VIP Port Connectivity function, a Request from the VIP EISS supporting a MAC Relay Entity; and   in response to the Request:
 providing by the Enhanced VIP Port Connectivity function, a corresponding Indication with identical parameters at the VIP SAP supporting the Higher Layer Entity; and 
 providing by the Enhanced VIP Port Connectivity function, a corresponding Request with identical parameters at the VIP EISS access point for the PIP. 
   
     
     
         6 . The method as recited in  claim 1 , wherein the step of configuring the Special Multiplexed SAP includes assigning to the Special Multiplexed SAP, a special I-SID value that is universally recognized to identify L2CPs. 
     
     
         7 . The method as recited in  claim 1 , wherein the step of utilizing the Service Instance Multiplex Entity to transfer frames includes the steps of:
 receiving by the Service Instance Multiplex Entity, an Indication from an Internal Sublayer Service (ISS) SAP; and   determining by the Service Instance Multiplex Entity, whether the initial octets of a mac_service_data_unit parameter include a valid service instance tag header;   if the initial octets include a valid service instance tag header:
 removing the tag header from the mac_service_data_unit; and 
 providing the Indication to a L2CP SAP; and 
   if the initial octets do not include a valid service instance tag header, providing the Indication unmodified to a PIP ISS SAP.   
     
     
         8 . The method as recited in  claim 1 , wherein the step of utilizing the Service Instance Multiplex Entity to transfer frames also includes the steps of:
 receiving by the Service Instance Multiplex Entity, a Request from the L2CP SAP;   modifying the mac_service_data_unit parameter by prepending a short service instance tag header using the I-SID value assigned to the Special Multiplexed SAP; and   providing the Request to the ISS SAP of the Service Instance Multiplex Entity.   
     
     
         9 . The method as recited in  claim 8 , wherein the step of utilizing the Service Instance Multiplex Entity to transfer frames also includes the steps of:
 receiving by the Service Instance Multiplex Entity, a Request or Indication from the PIP ISS SAP; and   providing the Request or Indication unmodified to the ISS SAP.   
     
     
         10 . A 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, said Bridge comprising:
 a Multiplexed Service Access Point (SAP) of a Service Instance Multiplex Entity for handling the frames of the Higher Layer Entity, said Multiplexed SAP having a Service Instance ID (I-SID) value that identifies Layer 2 Control Protocols (L2CPs); and   wherein the Service Instance Multiplex Entity is configured to utilize the Multiplexed SAP to transfer frames of L2CPs between the PIP or the Customer Backbone Port and the intended entity in the PBBN.   
     
     
         11 . The Bridge as recited in  claim 10 , further comprising:
 a Virtual Instance Port Service Access Point (VIP SAP) configured for every VIP and every Higher Layer Entity configured on the I-Component; and   an Enhanced VIP Port Connectivity function configured to utilize the VIP SAP to tunnel customer-initiated L2CPs.   
     
     
         12 . The Bridge as recited in  claim 10 , wherein the Enhanced VIP Port Connectivity function is further configured to:
 encapsulate the frames of the Higher Layer Entity that are initiated by the PIP and are required to reach Customer Networks placed on an opposite side of the PBBN; and   provide multiple copies of each frame destined to the VIP, wherein one copy is provided for the Enhanced Internal Sublayer Service (EISS) provided by each Bridge Port, and one copy is provided for each Higher Layer Entity attached to the VIP.   
     
     
         13 . The Bridge as recited in  claim 12 , wherein the Enhanced VIP Port Connectivity function is further configured to:
 receive an Indication from a VIP EISS access point for the PIP; and   responsive to the Indication, provide a corresponding Indication with identical parameters at a VIP EISS supporting a MAC Relay Entity and the VIP SAP supporting the Higher Layer Entity.   
     
     
         14 . The Bridge as recited in  claim 13 , wherein the Enhanced VIP Port Connectivity function is further configured to:
 receive a Request from the VIP EISS supporting a MAC Relay Entity; and   responsive to the Request:
 provide a corresponding Indication with identical parameters at the VIP SAP supporting the Higher Layer Entity; and 
 provide a corresponding Request with identical parameters at the VIP EISS access point for the PIP. 
   
     
     
         15 . The Bridge as recited in  claim 10 , wherein the Special Multiplexed SAP is assigned a special I-SID value that is universally recognized to identify L2CPs. 
     
     
         16 . The Bridge as recited in  claim 10 , wherein the Service Instance Multiplex Entity is configured to:
 receive an Indication from an Internal Sublayer Service (ISS) SAP;   determine whether the initial octets of a mac_service_data_unit parameter include a valid service instance tag header;   responsive to a determination that the initial octets include a valid service instance tag header:
 remove the tag header from the mac_service_data_unit; and 
 provide the Indication to a L2CP SAP; and 
   responsive to a determination that the initial octets do not include a valid service instance tag header, provide the Indication unmodified to a PIP ISS SAP.   
     
     
         17 . The Bridge as recited in  claim 10 , wherein the Service Instance Multiplex Entity is further configured to:
 receive a Request from the L2CP SAP;   modify the mac_service_data_unit parameter by prepending a short service instance tag header using the I-SID value assigned to the Special Multiplexed SAP; and   provide the Request to the ISS SAP of the Service Instance Multiplex Entity.   
     
     
         18 . The Bridge as recited in  claim 10 , wherein the Service Instance Multiplex Entity is further configured to:
 receive a Request or Indication from the PIP ISS SAP; and   provide the Request or Indication unmodified to the ISS SAP.   
     
     
         19 . A method of transporting frames of Higher Layer Entities from a Provider Instance Port (PIP) in a Provider Backbone Edge Bridge to Customer Networks placed on the opposite side of an intervening Provider Backbone Bridge Network (PBBN), said method comprising:
 receiving the frames from the PIP by an Enhanced Virtual Instance Port (VIP) Connectivity function on an I-Component of the Provider Backbone Edge Bridge;   encapsulating the frames as data frames; and   providing multiple copies of each frame destined to the VIP, wherein the Enhanced VIP Connectivity function provides one copy to an Enhanced Internal Sublayer Service (EISS) supporting a MAC Relay Entity and one copy for each VIP Service Access Point (SAP) supporting one of the Higher Layer Entities attached to the VIP.   
     
     
         20 . The method as recited in  claim 19 :
 wherein each Indication provided by a VIP EISS access point for the PIP results in a corresponding Indication with identical parameters at the VIP EISS and at the VIP SAPs supporting the Higher Layer Entities;   wherein each Request from a VIP EISS access point supporting the MAC Relay Entity results in a corresponding Indication with identical parameters at VIP SAP access points for the Higher Layer Entities, and in a corresponding Request with identical parameters at the VIP EISS access point for the PIP; and   wherein each Request from one of the VIP SAP access points supporting a Higher Layer Entity results in a corresponding Indication with identical parameters at the VIP EISS access point for the MAC Relay Entity, and at other VIP SAP access points for other Higher Layer Entities, and in a corresponding Request with identical parameters at an access point for a Local Area Network (LAN).