Service Instance Applied to MPLS Network

Abstract

Domain-wide unique node identifiers and domain-wide unique service identifiers are distributed within a MPLS domain using routing system LSAs. Nodes on the MPLS network compute shortest path trees for each destination and install unicast forwarding state based on the calculated trees. Nodes also install multicast connectivity between nodes advertising common interest in a common service identifier. Rather than distributing labels to be used in connection with unicast and multicast connectivity, the nodes deterministically calculate the labels. Any number of label contexts may be calculated. The labels may either be domain wide unique per unicast path or per multicast, or may be locally unique and deterministically calculated to provide forwarding context for the associated path. Multicast and unicast paths may be congruent, although this is not a requirement.

What is claimed is: 
     
         1 - 19 . (canceled) 
     
     
         20 . A first Multi-Protocol Label Switching (MPLS) network element for use in an MPLS network, the MPLS network element comprising:
 at least one communication interface;   at least one processor coupled to the communication interface; and   at least one storage element storing instructions for execution by the at least one processor, the instructions comprising:   instructions executable to receive routing advertisements from other network elements in the MPLS network;   instructions executable to develop a view of a topology of the MPLS network from the received routing advertisements;   instructions executable to receive from a second MPLS network element on the MPLS network, a service identifier in one of the routing advertisements; and   instructions executable to determine from the view of the topology of the MPLS network, whether the MPLS network element is on a shortest path tree rooted at the second MPLS network element;   instructions executable when the MPLS network element is on the shortest path tree rooted at the second MPLS network element to install forwarding state for the service identifier, the forwarding state comprising:   a first locally computed label to be used by the MPLS network element to forward traffic on the shortest path tree toward a destination; and   a second locally computed label to be used by a neighbor MPLS network element to forward traffic on the shortest path tree toward the destination.   
     
     
         21 . The first MPLS network element of  claim 20 , wherein the service identifier is unique within a domain of the MPLS network. 
     
     
         22 . The first MPLS network element of  claim 21 , wherein the service identifier is a network element node Identifier which is unique within the domain of the MPLS network. 
     
     
         23 . The first MPLS network element of  claim 21 , wherein the network element node identifier is an MPLS label which is unique within the domain of the MPLS network. 
     
     
         24 . The first MPLS network element of  claim 23 , configured to forward unicast traffic to the second network element on the MPLS network using the MPLS label which is unique within the domain of the MPLS network. 
     
     
         25 . The first MPLS network element of  claim 24 , configured, if the first MPLS network element installs forwarding state for the service identifier, to install forwarding state for the MPLS label such that any packet received by the first MPLS network element containing the MPLS label will be forwarded toward the second MPLS network element. 
     
     
         26 . The first MPLS network element of  claim 21 , configured to calculate the MPLS label by determining an MPLS label that is unique within the domain of the MPLS network and that may be used to forward traffic associated with the service instance. 
     
     
         27 . The first MPLS network element of  claim 26 , wherein the MPLS label is a unicast label associated with the destination node on the MPLS network. 
     
     
         28 . The first MPLS network element of  claim 26 , wherein the MPLS label is a multicast label associated with a source of a multicast. 
     
     
         29 . The first MPLS network element of  claim 20 , configured to calculate MPLS labels by calculating labels to be used to forward traffic associated with the service instance in a deterministic manner. 
     
     
         30 . The first MPLS network element of  claim 20 , configured to determine whether to install MPLS forwarding state for a service identifier by:
 determining whether the service identifier has been advertised by both the second MPLS network element and a third MPLS network element on the MPLS network; and   if the service identifier has been advertised by both the second MPLS network element and a third MPLS network element on the MPLS network, determining whether the first MPLS network element is on a forwarding path between second MPLS network element and the third MPLS network element.   
     
     
         31 . The first MPLS network element of  claim 20 , configured to send routing advertisements to neighboring network element of the MPLS network. 
     
     
         32 . The first MPLS network element of  claim 31 , configured to send the routing advertisements using a link state routing protocol in use on the MPLS network. 
     
     
         33 . The first MPLS network element of  claim 20 , wherein the instructions comprise:
 instructions executable to receive routing advertisements from other network elements in the MPLS network indicating interest in a multicast service instance; and   instructions executable to install MPLS forwarding state for the multicast service instance when the first MPLS network element is on a shortest path between two other network elements advertising interest in the multicast service instance, the MPLS forwarding state comprising:   a first locally computed label to be used by the MPLS network element to forward traffic associated with the multicast service instance; and   a second locally computed label to be used by a neighbor MPLS network element to forward traffic associated with the multicast service instance.   
     
     
         34 . The first MPLS network element of  claim 33 , wherein the forwarding state comprises a label associated with the multicast service instance, the label being unique within a domain of the MPLS network so that labels are not required to be signaled on the MPLS network to enable forwarding information to be installed by network elements on the MPLS network. 
     
     
         35 . The first MPLS network element of  claim 33 , wherein the forwarding state comprises a label associated with the multicast service instance which is not unique within a domain of the MPLS network, but is deterministically calculated by each of the MPLS network elements on the MPLS network, so that labels are not required to be signaled on the MPLS network to enable forwarding information to be installed by MPLS network elements on the MPLS network. 
     
     
         36 . A non-transitory processor readable storage medium storing instructions for execution by at least one processor of a first Multi-Protocol Label Switching (MPLS) network element in an MPLS network, the instructions comprising:
 instructions executable to receive routing advertisements from other network elements in the MPLS network;   instructions executable to develop a view of a topology of the MPLS network from the received routing advertisements;   instructions executable to receive from a second MPLS network element on the MPLS network, a service identifier in one of the routing advertisements; and   instructions executable to determine from the view of the topology of the MPLS network, whether the MPLS network element is on a shortest path tree rooted at the second MPLS network element;   instructions executable when the MPLS network element is on the shortest path tree rooted at the second MPLS network element to install forwarding state for the service identifier, the forwarding state comprising:   a first locally computed label to be used by the MPLS network element to forward traffic on the shortest path tree toward a destination; and   a second locally computed label to be used by a neighbor MPLS network element to forward traffic on the shortest path tree toward the destination.   
     
     
         37 . The medium of  claim 36 , wherein the instructions comprise instructions executable to determine whether to install MPLS forwarding state for a service identifier by:
 determining whether the service identifier has been advertised by both the second MPLS network element and a third MPLS network element on the MPLS network; and   if the service identifier has been advertised by both the second MPLS network element and a third MPLS network element on the MPLS network, determining whether the first MPLS network element is on a forwarding path between second MPLS network element and the third MPLS network element.   
     
     
         38 . The medium of  claim 36 , wherein the instructions comprise:
 instructions executable to receive routing advertisements from other network elements in the MPLS network indicating interest in a multicast service instance; and   instructions executable to install MPLS forwarding state for the multicast service instance when the first MPLS network element is on a shortest path between two other network elements advertising interest in the multicast service instance, the MPLS forwarding state comprising:   a first locally computed label to be used by the MPLS network element to forward traffic associated with the multicast service instance; and   a second locally computed label to be used by a neighbor MPLS network element to forward traffic associated with the multicast service instance.