Cisco Technology, Inc.

Hemant Singh

William Beebee

Madhu Sudan

Ralph Droms

Ole Troan

Chad Mikkelson

Shengyou Zeng

William Guckel

Mark E Millet

Joshua B Littlefield

Bernard Ernst Volz

De Fu Li

In one embodiment, methods are described for recovering lost customer premises equipment (CPE) information on a cable modem termination system (CMTS) in the presence of only Dynamic Host Control Protocol Version 6 (DHCPv6) CONFIRM. A CMTS purges routing information for an Internet Protocol Version 6 (IPv6) node, such as a CPE router, in response to detecting an interface reset for the IPv6 node. IPv6 addresses and prefixes information for the IPv6 node is gleaned from a DHCPv6 CONFIRM message received from the IPv6 node. By sending portions of the IPv6 addresses and prefixes information within a DHCPv6 LEASEQUERY message, a DHCPv6 CONFIRM message with an embedded DHCPv6 LEASEQUERY message, or a DHCPv6 CONFIRM message with an Interface-ID option, a reply message can be received that contains the purged routing information for the IPv6 node.

Recovering lost device information in cable networks

A method is provided in one example and includes determining that an access concentrator has lost customer premise equipment information. The method also includes obtaining the customer premise equipment information that is lost by evaluating Neighbor Discovery data and dynamic host configuration protocol version six (DHCPv6) query data. In more specific implementations, the method may include communicating a Bulk Leasequery message; receiving a response to the Bulk Leasequery message; and filtering out cable modem identifiers from the response to the Bulk Leasequery message.

System and method for recovery of customer premise equipment information on an access concentrator

A network processing device is configured to receive a configuration message from a host device and forward the configuration message to a server. The configuration message can be configured to request the server assign an Internet Protocol (IP) address to the host device. The network processing device can be configured to send at least one probe message to the host device responsive to receiving the configuration message. The network processing device can be configured to determine whether the host device intends to continue utilizing a previously assigned IP address in addition to the IP address requested by the configuration message based, at least in part, on any responses to the at least one probe message received from the host device.

Detection and support of a dual-stack capable host

Techniques for automatically identifying an edge-facing router in a network are provided. In one technique, a DHCP message is obtained at a router of a subscriber network. An options field of the DHCP message is identified. The options field of the DHCP message is analyzed to determine whether data in the options field indicates that first router is SP-facing. If it is determined that the router is an SP-facing router, then identification data that identifies the router as an SP-facing router is stored.

Automatically identifying an edge-facing router

Techniques are provided herein for receiving synchronization messages at a second network device that is in a hot standby configuration from a first network device that is maintaining Internet Protocol version 6 (IPv6) state machines for one or more neighbor devices. The synchronization messages are configured to indicate an IPv6 state for each state machine maintained in the first network device. An IPv6 state for corresponding state machines is updated in the second network device based on the synchronization messages such that the IPv6 states in the second network device allows the second network device to actively process IPv6 traffic for the one or more neighbor devices upon traffic switchover from the first network device to the second network device without restarting the corresponding IPv6 state machine associated with each of the one or more neighbor devices in the second network device. The roles of the first and second device with respect to active and standby state are reversed after a switchover.

Hot standby neighbor discovery protocol for internet protocol version 6

Techniques for automatically identifying an edge-facing router in a network are provided. In one technique, data is obtained at a first router of a subscriber network. The data may be included in a DHCP message or a NDP RA message. The first router determines, based on the data, whether the first router is a service provider (SP)-facing router, which is a router that is coupled to a SP router and no other router in the subscriber network is logically between the SP-facing router and the SP router. If it is determined that the first router is an SP-facing router, then the first router stores identification data that identifies the first router as an SP-facing router. Otherwise, the first router stores identification data that identifies the first router as a non-SP-facing router.

A CMTS or other data aggregation component having a DHCPv6 relay agent extracts a Media Access Control (MAC) address of an end device from a data packet received from an end device. A DHCPv6 data frame is created for transmission to a DHCPv6 server. The MAC address may be inserted into a specific option of the DHCPv6 data frame, where data in the option may not be processed by the server and are echoed back to the aggregation component or CMTS. The DHCPv6 data frame is transmitted to the DHCPv6 server. The component receives a response message from the server that may contain the MAC address or similar client hardware address as it was sent to the server by the network component. The network component may determine an outgoing port interface from which the response message should be sent, utilizing the MAC address and an interface bundling table. In this manner, interface bundling may be enabled.

Stateful DHCPv6 relay agent in a cable modem termination system

A network device is to receive traffic including neighbor discovery messages from requesting customer devices, and can detect the neighbor discovery messages within the traffic according to a distributed inspection scheme that includes the network device and a remote component. The network device is to then examine the neighbor discovery messages to determine if the neighbor discovery message should be forwarded to other of the customer devices, and respond to the requesting customer devices.

Neighbor discovery proxy with distributed packet inspection scheme

A hierarchical cable modem clone detection system: A cable modem clone detection system uses a cable modem media access control (MAC) address and physical location information such as information relating to a cable interface, upstream and downstream port numbers, fiber node information, and load balancing group descriptors to determine if a cable modem is a clone. The hierarchical approach first make a clone determination at a cable modem termination system, then at a regional operations center and finally at a network operations center.

Hierarchical cable modem clone detection

In one embodiment a technique is disclosed for facilitating communication between nodes and a head end of an access network including a head end, at least one shared access upstream channel and at least one downstream channel. A first insertion rate estimate is determined. In at least one embodiment, the first insertion rate estimate may relate to an estimated number of nodes attempting to sign-on to the access network during one or more time interval(s). In at least one embodiment, a frequency of occurrence of initial maintenance opportunities available to a first plurality of network nodes may be dynamically adjusted, for example, using data relating to the first insertion rate estimate. According to one embodiment where the access network corresponds to a cable network, the head end of the cable network may be operable to sign on at least 40,000 cable modems within a time interval of not more than 300 seconds.

Node registration technique implemented in access networks

Disclosed are methods and apparatus for translating data within a cable network between a first voice-over-IP (VOIP) protocol used by a user agent and a second VOIP protocol used by a call management server, or other type of call receiver. In one embodiment, data from an SIP (Session Initiation Protocol) user agent is translated for an NCS (Network Call Signaling) call management server. In one implementation, translation mechanisms are provided within the customer premises equipment in which the respective user agent is also configured.

Growing community of inventors

Westford, MA, United States of America

Hemant Singh