Cisco Technology, Inc.

Ya Xu

Anand Girish Parthasarathy

David Bianchi

Jean-Christophe Rode

This disclosure describes techniques for verifying compatibility of NOS image versions during startup of one or more hardware modules of a distributed router system. A client-server transaction protocol is executed between a communication server and a communication client configured according to the protocol to run on hardware modules of a distributed router system. A communication client discovers a communication server through a handshake transaction and sends a software image signature of an NOS image version. The communication server forwards the software image signature to an NOS verification server to determine whether the software image signature is compatible. Further, the communication server instructs the communication client to cause the hardware module hosting the communication client to boot either from a network interface or from local storage, at least in part on the determination of compatibility by the verification server, reducing numbers of reboots and increasing uptime and throughput of the system.

Client-server transaction protocol for compatibility verification

In one embodiment, the integrity of forwarding paths within a packet switching device is investigated. A packet switching device creates a probe packet. The packet switching device then communicates the probe packet within the packet switching device in a normal forwarding manner, while monitoring at multiple positions along forwarding paths through the packet switching device for the appearance of the probe packet. The traveling within the packet switching device of the probe packet, including as identified by the monitored positions, is analyzed to identify whether or not the probe packet was correctly forwarded at one or more locations within the packet switching device.

Investigating the integrity of forwarding paths within a packet switching device

In an OTN (Optical Transport Network), an OTN interface of a network element may receive a BDI (Backwards Defect Indicator) signal from a far end network element to which OTN frames are being transmitted. A BDI signal indicates the occurrence of a unidirectional failure in the transmission of OTN frames to which the far end network element responds by switching its routing to the network element. The OTN interface generates an AIS (Alarm Indication Signal) for its network element so that the network element switches network communication channels to the far end network element to ensure bidirectional switching upon a unidirectional failure.

Growing community of inventors

Sunnyvale, CA, United States of America

Ya Xu