A compromised node is one where the device can no longer be trusted by the network and/or operators. Nodes within an IEEE 802.15.4 PAN must possess the currently valid Group Temporal Key (GTK) to send and receive link-layer messages. The GTK is shared among all devices within the PAN and is refreshed periodically or on-demand. By communicating new GTKs to only trusted devices, compromised nodes may be evicted from the network.

In its route-over architecture, Cisco Resilient Mesh performs routing at the network layer using the Routing Protocol for Low-Power and Lossy Networks (RPL).

Cisco Resilient Mesh requires a Cisco 1000 Series Connected Grid Router (CGR) to provide connectivity to other IPv6 networks. The CGR (Field Area Router (FAR)) must serve as a RPL Directed Acyclic Graph (DAG) root and store information reported in DAO messages to forward datagrams to individual nodes within the mesh network.

The 6LoWPAN adaptation layer adapts IPv6 to operate efficiently over low-power and lossy links such as IEEE 802.15.4. The adaptation layer sits between the IPv6 and IEEE 802.15.4 layers and provides IPv6 header compression, IPv6 datagram fragmentation, and optimized IPv6 Neighbor Discovery.

Cisco Resilient Mesh implements frequency hopping across 64 channels with 400-kHz spacing in the 902 to 928 MHz ISM band. The frequency-hopping protocol used by Cisco Resilient Mesh maximizes the use of the available spectrum by allowing multiple sender-receiver pairs to communicate simultaneously on different channels. The frequency hopping protocol also mitigates the negative effects of narrowband interferers.

The Cisco Resilient Mesh bridge firmware can be installed by CLI or from IoT FND.

For more information on upgrading the firmware, see the latest Release Notes for Cisco 1000 Series Connected Grid Routers for Cisco IOS Release at: www.cisco.com/go/cgr1000-docs.

Cisco Resilient Mesh solution is managed and monitored by the Cisco IoT Field Network Director (FND), which provides the necessary backend network configuration, monitoring, event notification services, network stack firmware upgrade, as well as FND outage and meter registration. IoT FND also retrieves statistics on network traffic from the interface.

For more information on using IoT FND, refer to the latest version of Cisco IoT Field Network Director User Guide at:

https://www.cisco.com/c/en/us/support/cloud-systems-management/iot-field-network-director/products-installation-and-configuration-guides-list.html

Note	For a detailed description on the Cisco Resilient Mesh CLI, refer to Cisco Connected Grid WPAN Module for CGR 1000 Series Installation and Cisco Resilient Mesh Configuration Guide (Cisco IOS).

Cisco Resilient Mesh implements the CoAP Simple Management Protocol (CSMP) for remote configuration, monitoring, and event generation over the IPv6 network. The CSMP service is exposed over both the mesh and serial interfaces.

Cisco Resilient Mesh supports timely and efficient reporting of power outages and restorations.

In the event of a power outage, Cisco Resilient Mesh enters power-outage notification mode and the node stops listening for traffic to conserve energy. Cisco Resilient Mesh triggers functions to conserve energy by notifying the communication module and neighboring nodes of the outage. The outage notification is sent using the same security settings as any other UDP/IPv6 datagram transmission.

In the event of a power restoration, a Cisco Resilient Mesh node sends a restoration notification using the same communication method as the outage notification. The communication modules unaffected by the power outage event deliver the restoration notification.

You can register and manage Cisco Resilient Mesh Endpoints (RMEs) such as (meters) using the CSMP protocol.

This section summarizes resolved caveats to the Cisco Resilient Mesh.

• CSCvn99263

  FE FND (SF00778921) Range Extender changes device type & group after 5.6.21 FW.

• CSCvs12566

  Radio coming online after outage with Radio off procedure 119 specified.

• CSCvh60873

  CG-Mesh 5.6.21 fast reform performance degrades if DHCP reserve unlimited.

• CSCvh62236

  Fast reformation degrades if nodes' DHCPv6 lease time exceeds (2^32 - 1) seconds.

• CSCvp83516

  PAN leave reason is not reported to FND by meter.

You can use the Bug Search Tool to find information about caveats for this release, including a description of the problems and available workarounds. The Bug Search Tool lists both open and resolved caveats.

To access Bug Search Tool, you need the following items:

• Internet connection

• Web browser

• Cisco.com user ID and password

To access the Bug Search Tool, enter the following URL:

https://tools.cisco.com/bugsearch/search

You can look up explanations for console error message strings found in system logs at the following location:

http://www.cisco.com/en/US/partner/support/tsd_most_requested_tools.html

• Cisco CG-OS Release Notes for CGR 1000

  http://www.cisco.com/go/cgr1000-docs

• Cisco Connected Grid Module Guides

  http://www.cisco.com/go/cg-modules

• Cisco CGR 1240 Hardware Installation Guide

  http://www.cisco.com/go/cgr1000-docs

• Cisco CGR 1120 Hardware Installation Guide

  http://www.cisco.com/go/cgr1000-docs

Cisco CGR 1000 and 2000 Series Connected Grid Antennas Guides

https://www.cisco.com/c/en/us/td/docs/routers/connectedgrid/antennas/installing/cg_antenna_install_guide.html

Cisco Network Modules and Interface Cards Regulatory Compliance and Safety Information

http://www.cisco.com/en/US/docs/routers/access/interfaces/rcsi/IOHrcsi.html