Abstract: A method and apparatus for a hybrid variable rate pipe is described. In one embodiment of the invention, a computer implemented method of provisioning a non-BLSR protected layer 2/3 channel over a BLSR, provisioning a tunnel over the BLSR, and protecting the non-BLSR protected layer 2/3 channel between a first and second node of the BLSR with the tunnel is described.

Abstract: A method and apparatus for transmitting unscheduled flow control, in packet form, between two chips are described. In one embodiment, a method includes reading a status of a buffer used to receive network packets transmitted from a different chip. The method further includes transmitting to said different chip an unscheduled flow control packet including information about the status of the buffer. In an embodiment, a chip includes a packet buffer to store network packets transmitted from a different chip, wherein the packet buffer is associated with one or more of a plurality of ports through which the network packets travel. The chip also includes control circuitry, coupled with a packet data bus to receive said network packets from the different chip, and coupled with an unscheduled flow control packet bus to generate and transmit unscheduled flow control packets to the different chip, wherein the unscheduled flow control packets contain information relating to the packet buffer.

Abstract: Any size and location of concatenated packet data across Synchronous Optical Network (SONET) frames in a SONET signal is provided. In one embodiment, a method may include receiving portions of packets and placing the portions into buffers. Additionally, the method may determine packet boundaries among the portions of packets in the buffers to locate a number of packets. Additionally, the method may concatenate the packet data into a Time Division Multiplexing (TDM) SONET signal. The concatenation can be across any locations within the TDM SONET signal, and the size of the concatenation can be in increments of single SONET frames. In another embodiment, the number of packets may be concatenated within locations in the TDM SONET signal not occupied by the TDM data traffic. In one embodiment, the TDM SONET signal having the concatenated packet data may be transmitted.

Abstract: A method and apparatus for switching data of different protocols through a network are described. In one embodiment, a method includes receiving data from a number of interfaces. Additionally, the method includes switching the data through a first switch fabric upon determining that the data is being processed as packet data. The switching of the data through the first switch fabric includes de-encapsulating a first number of protocol headers from the packet data. The switching of the data through the first switch fabric also includes encapsulating a second number of protocol headers from the packet data. Moreover, the method includes switching the data through a second switch fabric upon determining that the data is being processed as Time Division Multiplexing (TDM) traffic.

Abstract: A method and apparatus for traffic scheduling is described. A computer implemented method comprises combining a priority scheme with a generalized processor sharing scheme to schedule transmission of a set of data and transmitting the set of data as scheduled.

Abstract: A method and apparatus for virtual private networks (VPNs) is described. A computer implemented method comprises determining a set of endpoints for a generic routing encapsulation (GRE) tunnel, determining a key (the key corresponding to a VPN), dynamically establishing the GRE tunnel with the set of endpoints and the key, and processing a set of GRE traffic for the VPN.

Abstract: A method and apparatus is described for receiving a new policy tree at a network element in a network. The network element stores a current policy tree of classes for quality of service of packets being processed by the network element. Classes of the current policy tree are compared with the classes of the new policy tree. Classes of the current policy tree are selectively deleted and classes of the new policy tree are selectively added to the current policy tree based on the comparison of the classes.

Abstract: A method and apparatus for a hybrid variable rate pipe is described. In one embodiment of the invention, a computer implemented method comprises provisioning a hybrid variable rate pipe on a span of an optical ring and transmitting a set of traffic in the hybrid variable rate pipe.

Abstract: Network elements at endpoints of a data connection are identified. A network path is generated between the network elements at the endpoints. The network path is validated by determining whether the network path provides at least one service requirement. The service requirement may be a minimum bandwidth requirement, a maximum bandwidth requirement, a maximum delay requirement, a maximum jitter requirement, a reliability requirement, a requirement that the network path includes network elements capable of acting as security gateways that bracket untrusted sections of the network path, a reachability requirement, or a data collection capability requirement. Network elements along a validated network path are configured to implement the service requirement. In one embodiment, the configuration performed on the network elements is recorded.

Abstract: A method and apparatus for controlling the admission of data packets into a network element is described. In an embodiment, a method for controlling admittance of a data packet into a memory buffer includes performing, prior to queuing the data packet for routing by a processor, the following: (1) receiving a data packet from one of at least two different ports, (2) determining a priority value within the data packet, and (3) determining an admittance group identifier for the data packet based on the priority value and the port the data packet was received. The method also comprises queuing the data packet from the memory buffer to one of a number of queues for routing by the processor upon determining that a number of data packets stored in the memory buffer and having the admittance group identifier is not greater than a threshold value.

Abstract: A machine readable medium for remote circuit provisioning is described. In one embodiment of the invention, a machine readable medium comprises receiving a packet on a circuit and provisioning the circuit in response to receiving the packet, wherein provisioning the circuit comprises retrieving parameters from a database, creating an empty circuit structure, and populating the empty circuit structure with the parameters.

Abstract: In an embodiment, a method comprises receiving a first instruction and a second instruction, where the second instruction specifies that a destination address of the first instruction should be replaced with a destination address of the second instruction. The method also includes decoding the first instruction and the second instruction. The decoding comprises replacing a destination address of the first instruction with an address provided by the second instruction, upon determining that the second instruction is a suffix instructions to the first instruction.

Abstract: A computer implemented method and apparatus for an attribute-oriented routing update is described. The method comprises selecting an updated set of attributes in a routing table before selecting a set of updated destinations associated with the selected set of attributes, wherein the attributes are stored in an attribute table as a portion of the routing table and the attributes do not include the conventional network prefixes. An update message that includes the set of updated destinations for the set of attributes is then generated. The method is also extended to extraction of unreachable destinations by using a dummy attribute in the routing table, wherein the dummy attribute is selected first, followed by extracting the unreachable destinations.

Abstract: Free memory can be managed by creating a free list having entries with address of free memory location. A portion of this free list can then be cached in a cache that includes an upper threshold and a lower threshold. Additionally, a plurality of free lists are created for a plurality of memory banks in a plurality of memory channels. A free list is created for each memory bank in each memory channel. Entries from these free lists are written to a global cache. The entries written to the global cache are distributed between the memory channels and memory banks.

Abstract: A method and apparatus for alignment of TDM-based signals for packet transmission using framed and unframed operations are described. In an embodiment, a line card in a network element includes a deframer unit that receives a Time Division Multiplexing (TDM) signal. The TDM signal includes a payload and overhead data. The deframer generates frame alignment data based on the overhead data. The line card also includes a packet engine unit coupled to the deframer unit. The packet engine unit receives the payload, the overhead data and the frame alignment data and generates a number of packet engine packets. The packet engine packets represent a frame within the TDM signal such that the packet engine packets include the payload, the overhead data and the frame alignment data. Additionally, the line card includes packet processor coupled to the deframer unit. The packet processor receives the packet engine packets and generates network packets based on the packet engine packets.

Abstract: A method and apparatus for simultaneously sync hunting signals is described. In one embodiment of the invention, a computer implemented method comprises initializing a first and second subset of a set of per-alignment state machines, receiving a first and second signal, and simultaneously sync hunting the first signal with the first subset of the set of per-alignment state machines and the second signal with the second subset of the set of per-alignment state machines.

Abstract: A method and apparatus for sync hunting signals is described. In one embodiment of the invention, a computer implemented method comprises receiving a signal and synchronization hunting concurrently for a first and second frame alignment pattern for a first and second alignment candidates.

Abstract: A method and apparatus for tunnel interworking is described. A computer implemented method comprises receiving a subscriber session with a first tunneling protocol and switching the subscriber session out with a second tunneling protocol.

Abstract: A method and apparatus for routing and forwarding between virtual routers is described. A method in a single network element comprises peering a first virtual router to a second virtual router, wherein the first and second virtual routers have separate address spaces and separate routing tables, distributing a set of one or more routes from the first virtual router to the second virtual router, wherein a first of the set of routes identifies the first virtual router as a next hop of the first route, said first route including a destination, and downloading to a set of one or more forwarding tables, the destination and the next hop.

Abstract: A method for enumerating sets of concurrent events handles single-shot events and recurring events. The method involves creating a data structure having records for time periods. The time periods begin and end on overall start and end times of scheduled events. In preferred embodiments the method creates the data structure by collapsing together master schedules for a plurality of resources. The method may create the master schedules by collapsing together mini-schedules of different priorities. The method can produce a minimal list of sets of concurrent events that will occur according to a universal master schedule in a form suitable for processing by an automatic validation system.