Abstract: An Ethernet local management interface (E-LMI) protocol for use at a user-to-network interface (UNI) of a Metro Ethernet Network (MEN) is disclosed. The E-LMI protocol allows configuration and status information for the services at the UNI to be transferred from the MEN to a customer edge device coupled to the MEN at the UNI. Various embodiments involve sending or receiving a message via a User-to-Network Interface (UNI) of a Metro Ethernet Network (MEN). A customer edge device extracts configuration and status information for the services at the UNI from a received message. The configuration and status information can correspond to a multipoint Ethernet Virtual Connection (EVC).

Abstract: A method involves receiving information identifying one or more virtual connections (VCs) available within a network and one or more IP subnets. The information is received by the first of several nodes coupled by the network and identifies either (or both) a first VC that is not locally available at the first node and a first IP subnet that is not configured on the first node. Information identifying a global topology of the network is generated, based upon the received information. The global topology includes each of several active VCs within the network and each of several IP subnets configured on the nodes coupled by the network. One of the IP subnets is then assigned to the one of the VCs, based upon the global topology of the network, until all of the IP subnets are assigned, each to a unique VC.

Abstract: Various systems and methods for integrating ring-protocol-compatible devices into network configurations that also include non-ring-protocol-compatible devices are disclosed. One such method, which can be performed by a network node that supports a ring protocol, involves generating a ring protocol packet and sending that ring protocol packet to a neighboring node. The ring protocol packet includes information, and the presence of this information within the packet causes a network device that receives the ring protocol packet to drop the ring protocol packet unless the network device supports a ring protocol. The information can include a reserved address (e.g., in the destination address field of the packet) as well as a ring protocol identifier.

Abstract: Various systems and methods for automatically configuring network devices coupled to a network that provides (or is capable of providing) multipoint virtual connections are disclosed. One such method involves receiving information identifying a plurality of virtual connections (VCs) available within a network. The method identifies a set of one or more nodes that are configured with one of several Internet Protocol (IP) subnets and that have access to one of the VCs, and then assigns each of the IP subnets to a unique one of the VCs.

Abstract: A system and method to automatically configure packet classification at a customer edge network device connecting a customer network to a service provider network. The method may comprise accessing the IP header of a packet received from the customer network to identify a customer service level classification of the packet. A memory may be accessed to retrieve service provider packet classification data identifying classes of service provided to the customer network. The packet classification of the service provider with the associated customer classification is associated and mapped, whereafter the Ethernet header of the packet may be populated with the mapped service provider packet classification.

Abstract: Various systems and method of preventing data traffic connectivity between endpoints of a network segment are disclosed. One method involves receiving a segment protocol message from a first segment port within a network segment, which includes a plurality of network devices. In response to receipt of the segment protocol message, which can indicate whether connectivity is present between the segment endpoints via the network segment, a second segment port can be operated in a blocked state. Operating the second segment port in the blocked state prevents data plane connectivity via the network segment.

Abstract: An Ethernet local management interface (E-LMI) protocol for use at a user-to-network interface (UNI) of a Metro Ethernet Network (MEN) is disclosed. The E-LMI protocol allows configuration and status information for the services at the UNI to be transferred from the MEN to a customer edge device coupled to the MEN at the UNI. Various embodiments involve sending or receiving a message via a User-to-Network Interface (UNI) of a Metro Ethernet Network (MEN). A customer edge device extracts configuration and status information for the services at the UNI from a received message. The configuration and status information can correspond to a multipoint Ethernet Virtual Connection (EVC).

Abstract: Various systems and methods for implementing virtual ports within ring networks are disclosed. For example, one method involves allocating a logical port that corresponds to a first port and a second port and instantiating a spanning tree protocol instance. The first port and the second port are both assigned to a first ring network. The spanning tree protocol instance selectively blocks the logical port; however, the spanning tree protocol instance is unable to block the first port independently of blocking the second port. Events (e.g., link failures and recoveries) that occur within the ring network are communicated to spanning tree by transitioning the state of the logical port in response to receiving a ring protocol control packet. The spanning tree protocol instance initiates a bridge protocol data unit (BPDU) exchange from the logical port in response to a transition in the state of the logical port.

Abstract: Various systems and methods for integrating ring-protocol-compatible devices into network configurations that also include non-ring-protocol-compatible devices are disclosed. One such method, which can be performed by a network node that supports a ring protocol, involves generating a ring protocol packet and sending that ring protocol packet to a neighboring node. The ring protocol packet includes information, and the presence of this information within the packet causes a network device that receives the ring protocol packet to drop the ring protocol packet unless the network device supports a ring protocol. The information can include a reserved address (e.g., in the destination address field of the packet) as well as a ring protocol identifier.

Abstract: Various systems and methods for integrating ring-protocol-compatible devices into network configurations that also include non-ring-protocol-compatible devices are disclosed. One such method, which can be performed by a network node that supports a ring protocol, involves generating a ring protocol packet and sending that ring protocol packet to a neighboring node. The ring protocol packet includes information, and the presence of this information within the packet causes a network device that receives the ring protocol packet to drop the ring protocol packet unless the network device supports a ring protocol. The information can include a reserved address (e.g., in the destination address field of the packet) as well as a ring protocol identifier.

Abstract: In one embodiment, an apparatus includes an access node, and the access node includes ports. The access node is operable to perform downlink switching based upon a unique Provider Virtual Local Area Network tag (S-TAG) and a unique IEEE 802.1Q tag header (C-TAG) that is assigned to each port.

Abstract: In some ring protocols, control messages are exchanged among ring nodes in order to implement certain behaviors, such as loop-free behavior and/or failure recovery, within the ring. A segment of a ring can be replaced by another network, effectively turning the ring into a daisy chain. If the intervening network does not allow transmission of the control messages used by the ring protocol, certain control messages may be blocked, causing the ring to operate in undesirable ways. Reflector ports can be implemented at each end of the daisy chain in order to prevent these control messages from being blocked.

Abstract: Methods and systems for distributing multicast messages in a network are disclosed. The use of such a method or system in an Ethernet network can result in a reduction in the number of flooded multicast messages. One method can involve receiving a companion message, which includes a multicast address, at a network device and extracting the multicast address from the companion message. The multicast address can then be associated with a VLAN and an interface of the network device. Another method involves receiving a join message, which identifies a multicast group being joined, and generating a companion message corresponding to the join message. The companion message includes an address of the multicast group.

Abstract: Various systems and methods for preventing loops in the presence of control plane failures are disclosed. For example, one method involves sending a special data packet in response to detection of a break in a network loop and then unblocking a port if the special data packet fails to circumnavigate the network loop. Prior to detection of the break, the port was blocked by a loop prevention protocol, such as a spanning tree protocol. If the special data packet successfully circumnavigates the network loop, the port will not be unblocked.

Abstract: Various systems and methods for implementing virtual ports within ring networks are disclosed. For example, one method involves allocating a logical port that corresponds to a first port and a second port and instantiating a spanning tree protocol instance. The first port and the second port are both assigned to a first ring network. The spanning tree protocol instance selectively blocks the logical port; however, the spanning tree protocol instance is unable to block the first port independently of blocking the second port. Events (e.g., link failures and recoveries) that occur within the ring network are communicated to spanning tree by transitioning the state of the logical port in response to receiving a ring protocol control packet. The spanning tree protocol instance initiates a bridge protocol data unit (BPDU) exchange from the logical port in response to a transition in the state of the logical port.

Abstract: Various systems and methods for automatically configuring network devices coupled to a network that provides (or is capable of providing) multipoint virtual connections are disclosed. One such method involves receiving information identifying a plurality of virtual connections (VCs) available within a network. The method identifies a set of one or more nodes that are configured with one of several Internet Protocol (IP) subnets and that have access to one of the VCs, and then assigns each of the IP subnets to a unique one of the VCs.

Abstract: A method involves receiving information identifying one or more virtual connections (VCs) available within a network and one or more IP subnets. The information is received by the first of several nodes coupled by the network and identifies either (or both) a first VC that is not locally available at the first node and a first IP subnet that is not configured on the first node. Information identifying a global topology of the network is generated, based upon the received information. The global topology includes each of several active VCs within the network and each of several IP subnets configured on the nodes coupled by the network. One of the IP subnets is then assigned to the one of the VCs, based upon the global topology of the network, until all of the IP subnets are assigned, each to a unique VC.

Abstract: Various systems and method of preventing data traffic connectivity between endpoints of a network segment are disclosed. One method involves receiving a segment protocol message from a first segment port within a network segment, which includes a plurality of network devices. In response to receipt of the segment protocol message, which can indicate whether connectivity is present between the segment endpoints via the network segment, a second segment port can be operated in a blocked state. Operating the second segment port in the blocked state prevents data plane connectivity via the network segment.

Abstract: Various systems and methods for integrating ring-protocol-compatible devices into network configurations that also include non-ring-protocol-compatible devices are disclosed. One such method, which can be performed by a network node that supports a ring protocol, involves generating a ring protocol packet and sending that ring protocol packet to a neighboring node. The ring protocol packet includes information, and the presence of this information within the packet causes a network device that receives the ring protocol packet to drop the ring protocol packet unless the network device supports a ring protocol. The information can include a reserved address (e.g., in the destination address field of the packet) as well as a ring protocol identifier.

Abstract: In one embodiment, an apparatus includes an access node, and the access node includes ports. The access node is operable to perform downlink switching based upon a unique Provider Virtual Local Area Network tag (S-TAG) and a unique IEEE 802.1Q tag header (C-TAG) that is assigned to each port.