Atrica Israel Ltd.

Atrica Ireland Limited

Nokia Siemens Networks Ethernet Solutions Ltd.

Lior Shabtay

Yaron Raz

Yoav Kluger

Ofir Friedman

Ronen Ofek

Amir Lahat

Golan Schzukin

Eyal Lichtman

Zhiping Jia

Doron Vider

Uri Avimor

Sergei Kaplan

Yoram Shamir

Dudu Akler

Leonid Shmulevich

Zacky Pickholz

A novel and useful hitless node insertion mechanism for configuring a new node to be inserted into an Ethernet network. The mechanism comprises pre-configuring the new node into a partially configured state, disconnecting a network link where the new node is to be inserted and connecting the new node to at least one end of the disconnected link. All data traffic received from neighboring nodes is then blocked and fake signal failure (SF) messages are generated and sent if Ethernet Ring Protection (ERP) messages are detected. An in-band management port is then selected and a configuration from a Network Management System (NMS) is received. Once configuration of the said new node is complete, the new node is set to a fully configured state.

Hitless node insertion for Ethernet networks

A novel mechanism for performing policy aware frame loss measurements that overcomes the problems of the prior art. The mechanism permits OAM frames to travel through the network in the same way data frames travel marked as green or yellow. The frame loss measurement is policy aware (i.e. SLA aware), taking CIR and EIR policy as well as policy in the middle of the network into consideration. In one embodiment, the value of the policer at the ingress to the client side is read just before sending an OAM frame and a potential decision value is calculated which reflects the decision that the policer would have taken if given the OAM frame at that time. If the calculated decision is to send the OAM frame as green or yellow, the frame is sent as green or yellow, accordingly. If, however, the calculated decision is to drop the frame, the frame is randomly marked as either green or yellow in accordance with the ratio of CIR to EIR. In another embodiment, red traffic (i.e. dropped frames) is simulated using CIR and EIR counters. In another embodiment, frame loss measurements are made that take into account the action taken by policers in the middle of the network.

Policy aware frame loss measurement

An apparatus for and method of packet loss measurement for TLS connections in an MEN that overcomes the problems of the prior art. The mechanism is operative to ensure that only one copy of each received packet is counted when exiting the TLS connection (unless dropped along the path due to congestion, etc.), so that the number of egress packets counted can be accurately compared with the number of ingress packets counted. Only a single copy of each packet is marked, i.e. flagged, at ingress. Any bridging along the path that needs to duplicate the packet forwards only a single marked copy of the packet. All other copies are forwarded unmarked. At the egress from the TLS, only marked packets are counted by the egress counter. In a second embodiment, a duplication field is inserted into each packet to better track all the duplicate copies of a packet.

Packet/octet loss measurement for bridging domains

A novel fast and scalable protection mechanism for protecting hierarchical multicast service in ring based networks. The mechanism of the present invention is especially suitable for use in Multi-Protocol Label Switching (MPLS) ring based networks such as Metro Ethernet Networks (MENs). The mechanism provides fast protection for MPLS based point-to-multipoint (P2MP) Label Switched Paths (LSPs) in a scalable manner. Each multicast connection on each ring in the network is split into two sub-LSPs: a primary P2MP sub-LSP originating on a primary node and a secondary P2MP sub-LSP originating on a secondary node traveling opposite to the primary path. For each node to be protected, a point-to-point protection tunnel is provisioned from that node to a secondary node that forwards the packets to the secondary path on all child rings connected to that parent ring through the protected node and that are provisioned to receive the specific multicast connection. In the event of a failure, all the multicast traffic on that ring is directed through the protection tunnel to the secondary node. Upon exiting the protection tunnel, the packets are forwarded to the secondary LSP on the child rings for which this node is the secondary node and also continue along the primary LSP on the parent ring and along all child rings for which this node is the primary node.

Scalable protection mechanism for hierarchical multicast service in ring based networks

An apparatus for and method of enforcing precedence of committed traffic over excess traffic that overcomes the difficulty in supporting committed over excess traffic and has particular application to distributed queuing systems. Queue control messages are generated and transmitted to other line cards to guarantee that committed traffic is not dropped when sent from multiple sources such as line interface cards to a single destination. When the level of a queue exceeds a threshold and flow control is received for the corresponding destination, the queue starts dropping excess traffic and messages indicating the queue status are sent to all other lines cards. When a line card receives a queue control message that another line card started dropping excess traffic to a specific destination, it also starts dropping excess traffic to that destination as well.

Apparatus for and method of support for committed over excess traffic in a distributed queuing system

A subport forwarding and provisioning mechanism whereby a plurality of subports implemented using slower speed processors are used to perform the packet processing for a higher speed packet stream. Outbound packets are assigned a subport based on their MPLS labels. Once assigned, the packets are forwarded to a particular subport. The output of all the subports is aggregated and combined into a single high speed packet stream and transmitted over the link. Inbound packets are received by the high speed PHY and forwarded to one of a plurality of subports. The subport chosen is the one having the same subport index as the one through which the packet was sent out over at the transmitting node. Conventional layer 2 switches can also be used whereby reserved source MAC addresses are assigned to subports. The switch forwards the inbound packets to one of the subports in accordance with the packet's source MAC address. The invention also comprises a mechanism for provisioning protection tunnels and a method for allocating subport bandwidth to subports.

Link multiplexing mechanism utilizing path oriented forwarding

A protection mechanism capable of providing both local and end-to-end connection protection for dual homed access/aggregation devices or customer-edge devices in a network. The protection mechanism provides end-to-end and fast local protection for off the shelf access devices that do not have any built in per-connection protection capabilities. The access device is connected via two separate physical uplinks to two edge switches of the network. For each connection to be protected, a main path is provisioned from one edge switch and an alternative path is provisioned from the other edge switch. The edge switches are adapted to comprise means for switching traffic from the main path to the alternative path in the event a failure along the main path is detected. Failures both in the stack portion, the core portion and in the access device uplinks are protected against.

Connection protection mechanism for dual homed access, aggregation and customer edge devices

An end-to-end monitoring mechanism whereby edge nodes are notified that a particular path flows through a local protection tunnel along the way. The notification mechanism utilizes OAM packets which include a link protection indication that are transmitted on the Ethernet service layer. The link protection indication may be represented by one or more flags to indicate that local protection is in place along the path. The mechanism enables fast local protection to be used with slower end-to-end protection by informing the latter when local protection is activated. In an implementation in which local-protection does not preserve the CIR of the protected traffic, the invention provides minimal interruption of Committed Information Rate (CIR) connections by minimizing the time traffic is diverted through local protection tunnels. Notification of the edge node that local protection is in use occurs very quickly, thus allowing the edge node to rapidly switch to a backup path.

End-to-end notification of local protection using OAM protocol

A link based network protection path calculation mechanism wherein a protection route is calculated that is guaranteed not to traverse the link it is intended to protect. The mechanism takes advantage of the fact that the same color cannot pass twice through the same optical fiber. The protection path is determined by eliminating all colors from the logical topology of the network except for the color corresponding to the link to be protected before executing the search algorithm. This serves to guarantee that the protection path calculated will not traverse the same physical fiber as the link to be protected. Virtual colors can be assigned to the links running through fiber bundles such that they do not pass through the same fiber/bundle twice.

Link level network protection path calculation mechanism for use in optical networks

A fast protection mechanism capable of maintaining end-to-end and fast local protection on the order of sub 50 ms for both VLAN only based connections and for connections that are based partially on VLAN technology and partially on MPLS technology. The present invention is suitable for use edge switches configured in a stack or ring topology. The NMS provisions both the main and alternative VLANs in each edge switch in the stack portions of the network. When a link failure occurs, the edge switches on either end of the failed link immediately switch all protected traffic going through that link to the alternative VLAN. The packets are then returned on the links over which they were received. Hello messages are used to signal the remote end that a link failure has occurred and that protected traffic must be switched to the main or alternative VLAN in accordance with the VLAN the Hello message was received on.

Fast connection protection in a virtual local area network based stack environment

A 1:N protection scheme that provides both equipment and line protection against a single point of failure for a network hub situated in an optical ring network. The invention is suitable for use in DWDM based optical ring networks, and in particular, in networks constructed having a logical star over physical ring topology. The hub is modified to comprise N+1 transceivers, assuming an N channel DWDM network wherein each of the N transmitters operates using a different wavelength. Protection against line failures is achieved by optically splitting the transmit signal into two paths and transmitting each separately in opposite directions over the ring (i.e. 1+1 protection). In the event of a line failure, the other signal should still arrive at the destination. Protection against equipment failures is achieved through the use of a spare transceiver having a tunable wavelength of operation (i.e. 1:N protection).

Network hub employing 1:N optical protection

A path reroute mechanism for use in communication networks comprising multiple searches for a routing path to restore traffic following a failure that could not be protected by a previously established protection route (i.e. protection tunnel, bypass, etc.) or for routing or rerouting of traffic paths for optimization or any other purpose. Each node advertises TLVs that include bandwidth allocation information used to derive the actual amount of bandwidth available for protection purposes, protected paths and unprotected paths or a portion of this information such as in the case where unprotected paths are not supported. Searches are performed on larger and larger portions of the available bandwidth until a route for the path is found.

Path rerouting mechanism utilizing multiple link bandwidth allocations

A mechanism and associated protocol for performing Service Level Agreement (SLA) measurements in a communications network. The measurements obtained are used to perform various SLA parameter calculations such as delay, round trip delay, one way jitter and bandwidth related calculations. SLA measurement request and response messages are stamped with time and bandwidth counters by the client and remote ends of a connection. The resultant data is used to perform the calculation of SLA parameters.

Growing community of inventors

Ganei Tikva, Israel

Lior Shabtay