Cisco Technology, Inc.

Telefonaktiebolaget Lm Ericsson (publ)

Anantha Ramaiah

Chandrashekhar Appanna

Amol Khare

Keyur Patel

Mitesh Dalal

Randall R Stewart

Kaushik Pratap Biswas

Ruchi D Kapoor

Shrirang Arvind Bage

Vamsidhar Valluri

Peter Lei

Senthil M Sivakumar

Lester Bird

Balaji Pitta Venkatachalapathy

Isidor Kouvelas

Patrick Mahan

David Delano Ward

Brian Eliot Weis

Alpesh S Patel

Gopal K Dommety

Lin Han

Robert Raszuk

Manoj Kumar Pandey

Balachander Chandrasekaran

Mahadev Somasundaram

Praveen Joshi

Saravanan Agasaveeran

Syam Sundar Appala

Sharad Ahlawat

Manikchand Roopchand Bafna

Satish Mynam

Mahesh Jethanandani

Narayana Hosdurg Pai

Siva Yaragalla

John C Wong

In one embodiment, an apparatus includes a first transport stack, a virtual network interface controller (VNIC), and a second transport stack. The first transport stack is associated with an Internetwork Operating System (IOS), as well as with a plurality of interface-based Internet Protocol (IP) addresses and a plurality of IP addresses. The VNIC is configured to dynamically provision the plurality of interface-based IP addresses and the plurality of IP addresses. The second transport stack is associated with a kernel, and configured to communicate with a first application. The MS is configured to enable the first application to share the plurality of IP addresses and the plurality if IP addresses with a plurality of applications.

Enabling applications in a multi-transport stack environment

In an embodiment, a method comprises establishing a first data communications session with a first router. In response to receiving a first request to establish a second data communications session, a probe message that is configured to test whether the first data communications session or the first router is responsive is sent to the first router. In response to determining that the first router has not acknowledged the probe message before a probe timer has expired, and receiving a second request to establish the second data communications session, the second data communications session with the first router is established and a state for the first data communications session is deleted.

Restarting network reachability protocol sessions based on transport layer authentication

In one embodiment, a router selects a particular peer from an original update group used with an Exterior Gateway Protocol (EGP) such as Border Gateway Protocol (BGP). The original update group includes a plurality of peers of the router that share a same outbound policy and that receive common update messages, from the router, of routing table information. The router determines that the particular peer is a potential slow peer based on a first type of indicia, wherein a slow peer is a peer that cannot keep up with a rate at which the router generates update messages over a prolonged period of time. The router confirms that one or more second types of indicia are consistent with the particular peer being a slow peer. In response to the confirmation, the router determines that the particular peer is a slow peer.

BGP slow peer detection

In one embodiment, an apparatus comprises logic for optimizing return traffic paths using network address translation (NAT). The logic is operable to receive outbound data from a source node in a source network, and to replace a source address in a source address field in the outbound data with a first address from a first address pool associated with a first connection. The logic is operable to determine that return traffic on the first connection needs to be switched over to a second connection, where a second address pool is associated with the second connection. The logic is operable to generate a mapping that associates the first address with a second address from the second address pool and, based on the mapping, to replace the first address in the source address field in the outbound data with the second address. The logic is also operable to send the outbound data to the destination node over the second connection.

Optimizing return traffic paths using network address translation

A system and method supporting efficient, scalable stateful switchover of transport layer connections in a telecommunications network element. One method involves receiving, at a network element comprising an active transport protocol process coupled to a standby protocol process, a request to configure a first transport layer connection maintained at the active transport protocol process for stateful switchover; receiving an event associated with the first transport layer connection; creating a message containing replicated event information based on the received event; sending the message to the standby transport protocol process; and processing the message at the standby transport protocol process, wherein the standby transport protocol process replicates state information for the first connection.

High availability transport protocol method and apparatus

A method and non-transitory computer-readable medium are disclosed for extending a hold timer that binds an application-layer session when a transport-layer out-of-order message queue includes an out-of-order message for the application-layer session. An application receives an application-layer message from transport protocol logic that is configured to deliver in-order application-layer messages to the application. The received application-layer message is a next in-order application-layer message for an application-layer session that is bound by a hold timer. After an amount time has passed, the application detects an expiration of the hold timer. In response, rather than immediately tearing down the application-layer session, the application inspects an out-of-order queue of the transport protocol logic. The hold timer is extended when the out-of-order queue includes an out-of-order application-layer message for the application-layer session. In one aspect, the transport protocol logic includes an application programming interface that provides the application with access to the out-of-order queue.

Extending application-layer sessions based on out-of-order messages

A method for detecting unavailable network connections comprises, at a first data processing node that is hosting a transport protocol connection that uses a plurality of sequence values to identify messages sent to a peer node, wherein the first node is communicatively coupled to a second data processing node serving as a redundant backup, periodically sending a checkpoint sequence value to the second node; detecting that either the transport protocol connection or a process using the transport protocol connection is unavailable, without use of a timeout; and in response thereto, sending a notification to the peer node, wherein the notification includes the checkpoint sequence value. One embodiment provides for rapidly detecting and responding to failure of a TCP process without using long timeouts as conventionally provided in long-lived applications that run on top of TCP.

Detecting unavailable network connections

A method of preventing network denial of service attacks by early discard of out-of-order segments comprises creating a reassembly queue for a connection between a first network node and a second network node, wherein the connection has been established based on a transport-layer network protocol, the reassembly queue having a size based on a buffer size of an input interface with which the connection is associated. As out-of-order data segments arrive on the connection, and before other processing of the segments, whether the reassembly queue is full is determined, and the out-of-order segments are discarded if the reassembly queue is full. The size of the reassembly queue is automatically changed in response to one or more changes in any of network conditions and device resources.

Preventing network denial of service attacks by early discard of out-of-order segments

A system and method for performing stateful switchover with reduced data, such as only metadata about a TCP window state. The metadata comprises a size of TCP packets used to send BGP messages, and which of those have been acknowledged by a neighbor networking device. The networking device comprises a BGP module to establish a BGP session between the networking device and a neighbor networking device. An active transport module within the networking device synchronizes with a standby transport module within the networking device by sending the metadata. A fault detector within the networking device initiates a stateful switchover from the active transport module to the standby transport module responsive to detecting a failure of a process and/or processor. The standby transport module uses the metadata to determine stateful metadata for preserving current BGP and TCP sessions of the networking device.

Cooperative TCP / BGP window management for stateful switchover

In an embodiment, an existing transport protocol connection though a mobile device is recognized as having entered a state of disconnect. A lowest received sequence number is determined from received messages to be transmitted over a disconnected transport protocol connection. A disconnect acknowledgement message with a receive window of zero and a sequence number of one less than the lowest received sequence number is transmitted. The disconnect acknowledge message with a receive window of zero and a sequence number of one less than the lowest received sequence number is continued to be transmitted until the transport protocol connection exits the disconnect state to a connect state.

Disconnected transport protocol connectivity

A system and method supporting synchronization of replicated transport layer connections in a redundant processor telecommunications network element. One method involves receiving, at a network element comprising an active transport protocol process coupled to a standby transport protocol process, information identifying a newly created transport layer connection maintained at the active transport protocol process; assigning a unique connection identifier to the transport layer connection; sending the unique connection identifier, in association with other, protocol-specific connection identifying information, to the standby protocol process; and sending, to the standby transport protocol process, one or more messages comprising one or more properties or statistics associated with the transport layer connection, wherein the messages identify the transport layer connection using the unique connection identifier.

Transport protocol connection synchronization

Growing community of inventors

Sunnyvale, CA, United States of America

Anantha Ramaiah