Abstract: Routing packets by a router involves establishing a first flow configured for forwarding the packets from a first ingress interface to a first egress interface of the router; determining a condition to modify the first flow; deactivating the first flow; establishing a second flow configured for forwarding the packets from at least one of (1) the first ingress interface to a second egress interface, (2) a second ingress interface to the first egress interface, or (3) a second ingress interface to a second egress interface; and activating the second flow.

Abstract: A routing method checks a network path selected for transmitting a stream of packets between a first routing node and a second routing node in a computer network. The stream of packets complies with a first transport protocol. The method forwards, from the first routing node toward the second routing node, a set of handshake packets. The set of handshake packets includes change information indicating a change in the transport protocol for a plurality of the packets in the stream. The method modifies the plurality of packets in the stream (“modified packets”). Specifically, the method modifies the first transport protocol header in the plurality of packets in the stream to have a second transport protocol header of a second transport protocol. This modification preferably does not increase the packet size of each of modified packets.

Abstract: Embodiments of the present invention provide for continuity of “stateful” routing sessions in the presence of source network address translation (NAT). Specifically, a stateful routing session may be moved from one routing path to another routing path, e.g., due to a routing change in the communication network, where the routing paths have different source NAT status. For example, the stateful routing session may be moved from a path having no source NAT to a path having source NAT, from a path having source NAT to a path having no source NAT, or from paths having different source network address translations. When a stateful routing session is moved from an existing routing path to a new routing path, the routers detect the routing change based on the change in source NAT status using a special link monitoring protocol.

Abstract: A routing method checks a network path selected for transmitting a stream of packets between a first routing node and a second routing node in a computer network. The stream of packets complies with a first transport protocol. The method forwards, from the first routing node toward the second routing node, a set of handshake packets. The set of handshake packets includes change information indicating a change in the transport protocol for a plurality of the packets in the stream. The method modifies the plurality of packets in the stream (“modified packets”). Specifically, the method modifies the first transport protocol header in the plurality of packets in the stream to have a second transport protocol header of a second transport protocol. This modification preferably does not increase the packet size of each of modified packets.

Abstract: A router is specially configured to implement a bilateral TCP state machine to monitor the status of TCP sessions based on TCP sequence numbers in both forward session packets and return session packets received by the router for a TCP bi-flow session. Among other things, the router may determine the status of a TCP session, for example, based on statistical information such as the number or rate of errors detected (e.g., the number of dropped packets, duplicated packets, out-of-sequence packets, and/or out-of-window packets). Each router is typically configured to collect and store status information and optionally also to use the status information in making intelligent routing decisions, such as, for example, deciding whether or not to forward a particular packet, deciding whether to reconfigure a bi-flow routing session, or updating routing table information used for routing packets.

Abstract: A router is specially configured to implement a bilateral TCP state machine to monitor the status of TCP sessions based on TCP sequence numbers in both forward session packets and return session packets received by the router for a TCP bi-flow session. Among other things, the router may determine the status of a TCP session, for example, based on statistical information such as the number or rate of errors detected (e.g., the number of dropped packets, duplicated packets, out-of-sequence packets, and/or out-of-window packets). Each router is typically configured to collect and store status information and optionally also to use the status information in making intelligent routing decisions, such as, for example, deciding whether or not to forward a particular packet, deciding whether to reconfigure a bi-flow routing session, or updating routing table information used for routing packets.

Abstract: A method has provides a router having an input, an output, and a shared memory. The router also has a forwarding path to forward a plurality of packets from the input to the output, and a service path to manage statistical data relating to packets forwarded through the forwarding path. The forwarding path has a counter to count aggregate packet information relating to the plurality of packets it forwards. Next, the method counts, using the counter(s), aggregate packet information relating to the packets forwarded through the forwarding path to produce count information. After producing the count information, the method uses the forwarding path to store the count information in the shared memory of the router, and then causes the service path to retrieve the count information from the shared memory. The service path ultimately produces statistical information using the count information retrieved from the shared memory.

Abstract: Embodiments of the present invention provide for continuity of “stateful” routing sessions in the presence of source network address translation (NAT). Specifically, a stateful routing session may be moved from one routing path to another routing path, e.g., due to a routing change in the communication network, where the routing paths have different source NAT status. For example, the stateful routing session may be moved from a path having no source NAT to a path having source NAT, from a path having source NAT to a path having no source NAT, or from paths having different source network address translations. When a stateful routing session is moved from an existing routing path to a new routing path, the routers detect the routing change based on the change in source NAT status using a special link monitoring protocol.

Abstract: Routing packets by a router involves establishing a first flow configured for forwarding the packets from a first ingress interface to a first egress interface of the router; determining a condition to modify the first flow; deactivating the first flow; establishing a second flow configured for forwarding the packets from at least one of (1) the first ingress interface to a second egress interface, (2) a second ingress interface to the first egress interface, or (3) a second ingress interface to a second egress interface; and activating the second flow.

Abstract: A method has provides a router having an input, an output, and a shared memory. The router also has a forwarding path to forward a plurality of packets from the input to the output, and a service path to manage statistical data relating to packets forwarded through the forwarding path. The forwarding path has a counter to count aggregate packet information relating to the plurality of packets it forwards. Next, the method counts, using the counter(s), aggregate packet information relating to the packets forwarded through the forwarding path to produce count information. After producing the count information, the method uses the forwarding path to store the count information in the shared memory of the router, and then causes the service path to retrieve the count information from the shared memory. The service path ultimately produces statistical information using the count information retrieved from the shared memory.