Abstract: Techniques are disclosed for performing time synchronization at a plurality of computing devices in a network. In one example, a method comprising obtaining timestamp data in accordance with a synchronization operation for a timing protocol; computing a skewness estimate and an offset estimate from the timestamp data by executing a regression analysis, wherein the regression analysis is configured to train a first model to predict the offset estimate and the skewness estimate, the offset estimate comprising a clock time difference between the first clock and the second clock; computing a corrected skewness estimate and a corrected offset estimate based on a second model having parameters based on the offset estimate and the skewness estimate; and modifying a current time value of at least one of the first clock or the second clock based on at least one of the corrected offset estimate or the corrected skewness estimate.

Abstract: In general, techniques are described for a hierarchical, distributed DHCP system for managing IP address assignment among distributed networks of computing devices. For example, a system may include a central DHCP server configured to manage a plurality of distributed DHCP servers, each distributed DHCP server configured to perform DHCP using IP addresses allocated from a common prefix for a tenant associated with computing devices managed by multiple DHCP servers. The central DHCP server allocates IP addresses to the distributed DHCP servers, e.g., on an on-demand basis from the common pool and may handle concurrent requests for IP addresses from distributed DHCP servers. Each of the distributed DHCP servers may store records for IP addresses and media access control (MAC) addresses for computing devices managed by that distributed DHCP server, and the DHCP servers may send these records to the central DHCP server to facilitate IP assignment coherency.

Abstract: Methods and apparatus for aggregating communication channels. In one exemplary embodiment an aggregation device is required only on one side of the set of communication channels being aggregated. Advantageously, no modifications to the source and/or destination of data transfers are required for operation of the invention. In one embodiment utilized for data transfers in the downstream direction, object download requests can be fulfilled by sending a sequence of partial download requests through the set of communication channels being aggregated, and forwarding the resulting partial data objects received to the original requestor in the proper order. In another embodiment utilized for upstream data transfers, traffic is bifurcated to travel along a set of communication channels, and the bifurcated traffic is reassembled either at the network layer or the transport layer.

Abstract: In one embodiment, a method for load balancing in a software-define networking (SDN) system includes, upon receiving a packet, determining whether a matching entry for the packet in a server distribution table contains both a current and new server selection. If the matching entry contains both, it is determined whether there is a matching entry for the packet in a transient flow table, where the transient flow table maintains server selections when at least one of the plurality of servers is reconfigured. Upon determining that there is no matching entry for the packet in the transient flow table, the method determines whether the packet is a first packet of a traffic flow. If the packet is the first packet of a traffic flow, the packet is forwarded according to the new server selection of the matching entry in the server distribution table, and the transient flow table is updated.

Abstract: Exemplary methods for performing service chaining include generating a plurality of service chaining (SC) next hops (NHs) by, for each SC NH hop, generating a plurality of SC maps, each SC map identifying a chain of one or more service modules, wherein each service module is to apply a corresponding service on a packet. The methods further include generating a plurality of hosted NHs, each hosted NH including forwarding information that causes the packet to be forwarded to a corresponding service module. The methods further include in response to receiving a first packet, identifying a SC NH of the plurality of SC NHs based on an Internet Protocol (IP) address of the first packet, and forwarding the first packet to a service module based on the identified SC NH.

Abstract: A method/system for removing redundancy in packets is disclosed. In one embodiment, for each of the sets of one or more consecutive bytes within the packet, the method divides the one or more consecutive bytes into a plurality of non-overlapping, consecutive segments; generates a segment feature for each of the plurality of non-overlapping, consecutive segments through application of a plurality of cryptographic hash functions with different random seeds; generates a single duplication feature based on a combination of the segment features for the plurality of non-overlapping, consecutive segments; and generates a single compressed string when a predetermined condition is met, based on a comparison of the single duplication feature and a set of stored duplication features. The method continues with sending the resulting strings in place of the packet toward the packet's destination.

Abstract: A method of aggregating a plurality of packet based communication channels is provided by the system. The communication channels connect two common endpoints, and aggregation devices are present at each endpoint to implement an aggregation policy. The system provides a dynamic aggregation system where m aggregation policy is employed on a per packet flow basis. Packet flows can be classified by application type, so that an appropriate aggregation policy can be used for packets belonging to the flow. The selected aggregation policy is used for each flow within the aggregation devices at each endpoint.

Abstract: Methods may be provided to forward data packets to a plurality of servers with each server being identified by a respective server identification (ID). A non-initial data packet of a data flow may be received, with the non-initial data packet including information for the data flow, and a bucket ID for the non-initial data packet may be computed as a function of the information for the data flow. Responsive to the bucket ID for the data packet mapping to first and second server identifications (IDs) of respective first and second servers and responsive to the non-initial data packet being a non-initial data packet for the data flow, the non-initial data packet may be transmitted to one of the first and second servers using one of the first and second server IDs based on a flow identification of the data flow being included in a transient table for the bucket ID.

Abstract: In one embodiment, a method for load balancing in a software-define networking (SDN) system includes, upon receiving a packet, determining whether a matching entry for the packet in a server distribution table contains both a current and new server selection. If the matching entry contains both, it is determined whether there is a matching entry for the packet in a transient flow table, where the transient flow table maintains server selections when at least one of the plurality of servers is reconfigured. Upon determining that there is no matching entry for the packet in the transient flow table, the method determines whether the packet is a first packet of a traffic flow. If the packet is the first packet of a traffic flow, the packet is forwarded according to the new server selection of the matching entry in the server distribution table, and the transient flow table is updated.

Abstract: In one embodiment, a method for load balancing in a software-define networking (SDN) system includes, upon receiving a packet, determining whether a matching entry for the packet in a server distribution table contains both a current and new server selection. If the matching entry contains both, it is determined whether there is a matching entry for the packet in a transient flow table, where the transient flow table maintains server selections when at least one of the plurality of servers is reconfigured. Upon determining that there is no matching entry for the packet in the transient flow table, the method determines whether the packet is a first packet of a traffic flow. If the packet is the first packet of a traffic flow, the packet is forwarded according to the new server selection of the matching entry in the server distribution table, and the transient flow table is updated.

Abstract: A packet distribution scheme for forwarding incoming packets to servers in a network. Depending on a hash value of the incoming flow's identification parameters, a hash flow table or database is queried to determine the server to which the packet is to be forwarded. If multiple flows have the same hash index and are associated with different servers, a secondary flow table or database is queried for determining the server. In an example implementation, only the secondary flow table is configured to store fully qualified flow identification parameters whereas the hash flow table is operative to store reduced or compressed state information.

Abstract: A method of operating a load balancing switch may include providing a flow entry in a flow table, the flow entry may include a match pattern that is satisfied by a data flow identification, and the flow entry may identify a first server. A first data packet including a first data flow identification may be received, and the first data packet may be transmitted to the first server responsive to the first data flow identification satisfying the match pattern. After transmitting the first data packet to the first server, the flow entry may be modified so that the flow entry identifies the first server and a second server. After modifying the flow entry, a second data packet including a second data flow identification may be received, and the second data packet may be transmitted to the first and second servers responsive to the second data flow identification satisfying the match pattern.

Abstract: Exemplary methods for performing service chaining include generating a plurality of service chaining (SC) next hops (NHs) by, for each SC NH hop, generating a plurality of SC maps, each SC map identifying a chain of one or more service modules, wherein each service module is to apply a corresponding service on a packet. The methods further include generating a plurality of hosted NHs, each hosted NH including forwarding information that causes the packet to be forwarded to a corresponding service module. The methods further include in response to receiving a first packet, identifying a SC NH of the plurality of SC NHs based on an Internet Protocol (IP) address of the first packet, and forwarding the first packet to a service module based on the identified SC NH.

Abstract: In one embodiment, a method for load balancing in a software-define networking (SDN) system includes, upon receiving a packet, determining whether a matching entry for the packet in a server distribution table contains both a current and new server selection. If the matching entry contains both, it is determined whether there is a matching entry for the packet in a transient flow table, where the transient flow table maintains server selections when at least one of the plurality of servers is reconfigured. Upon determining that there is no matching entry for the packet in the transient flow table, the method determines whether the packet is a first packet of a traffic flow. If the packet is the first packet of a traffic flow, the packet is forwarded according to the new server selection of the matching entry in the server distribution table, and the transient flow table is updated.

Abstract: A method/system for removing redundancy in packets is disclosed. In one embodiment, for each of the sets of one or more consecutive bytes within the packet, the method divides the one or more consecutive bytes into a plurality of non-overlapping, consecutive segments; generates a segment feature for each of the plurality of non-overlapping, consecutive segments through application of a plurality of cryptographic hash functions with different random seeds; generates a single duplication feature based on a combination of the segment features for the plurality of non-overlapping, consecutive segments; and generates a single compressed string when a predetermined condition is met, based on a comparison of the single duplication feature and a set of stored duplication features. The method continues with sending the resulting strings in place of the packet toward the packet's destination.

Abstract: Methods and apparatus for aggregating communication channels. In one exemplary embodiment an aggregation device is required only on one side of the set of communication channels being aggregated. Advantageously, no modifications to the source and/or destination of data transfers are required for operation of the invention. In one embodiment utilized for data transfers in the downstream direction, object download requests can be fulfilled by sending a sequence of partial download requests through the set of communication channels being aggregated, and forwarding the resulting partial data objects received to the original requestor in the proper order. In another embodiment utilized for upstream data transfers, traffic is bifurcated to travel along a set of communication channels, and the bifurcated traffic is reassembled either at the network layer or the transport layer.

Abstract: A method of operating a load balancing switch may include providing a flow entry in a flow table, the flow entry may include a match pattern that is satisfied by a data flow identification, and the flow entry may identify a first server. A first data packet including a first data flow identification may be received, and the first data packet may be transmitted to the first server responsive to the first data flow identification satisfying the match pattern. After transmitting the first data packet to the first server, the flow entry may be modified so that the flow entry identifies the first server and a second server. After modifying the flow entry, a second data packet including a second data flow identification may be received, and the second data packet may be transmitted to the first and second servers responsive to the second data flow identification satisfying the match pattern.

Abstract: Methods and apparatus for aggregating communication channels. In one exemplary embodiment an aggregation device is required only on one side of the set of communication channels being aggregated. Advantageously, no modifications to the source and/or destination of data transfers are required for operation of the invention. In one embodiment utilized for data transfers in the downstream direction, object download requests can be fulfilled by sending a sequence of partial download requests through the set of communication channels being aggregated, and forwarding the resulting partial data objects received to the original requester in the proper order. In another embodiment utilized for upstream data transfers, traffic is bifurcated to travel along a set of communication channels, and the bifurcated traffic is reassembled either at the network layer or the transport layer.

Abstract: A packet distribution scheme for forwarding incoming packets to servers in a network. Depending on a hash value of the incoming flow's identification parameters, a hash flow table or database is queried to determine the server to which the packet is to be forwarded. If multiple flows have the same hash index and are associated with different servers, a secondary flow table or database is queried for determining the server. In an example implementation, only the secondary flow table is configured to store fully qualified flow identification parameters whereas the hash flow table is operative to store reduced or compressed state information.

Abstract: A first data packet of a data flow may be addressed to a primary address and include information for the data flow and a bucket ID may be computed based on the information. Responsive to the bucket ID mapping to first and second servers and the first data packet being addressed to the primary address, the first data packet may be transmitted to the first server. A second data packet may be received addressed to a stand-by address and including the information for the data flow, and a bucket ID may be computed based on the information with the bucket IDs for the first and second packets being the same. Responsive to the bucket ID for the second data packet mapping to first and second servers and the second data packet being addressed to the stand-by address, the second data packet may be transmitted to the second server.