30 January 2019
The wave of transformation brought about by digitisation, the IoT, and decentralised hardware offers many efficiency benefits. However, these changes have created new challenges for centralised IT departments managing distributed branches, production sites and private clouds to avoid the consequential costs of network downtime.
Distributed networks are often more susceptible to service interruption and generally only larger branches will have an IT expert on site. With centralised monitoring and remote access to distributed resources, today administrators in many organisations can manage dozens or even hundreds of sites efficiently using in band tools such as Telnet (teletype network). However, access is not possible during major technical issues such as network or connectivity failure.
In the legacy world, a remote failure would mean a technician has to go on site to resolve the problem that could range from a simple reboot to having to order a replacement device. The modern alternative to dispatching technicians is ‘out-of-band’ management that is independent of the function and connectivity of the local network which allows admins the ability to resolve issues remotely, to enhance resiliency and ultimately reduces downtime.
The principle is simple. Network attached devices are normally fitted with serial interfaces which can be interrogated independently of the network and give the administrator a complete picture of the status of the device. Many of the important management functions such as firmware updates are only available via serial console interfaces. If a device no longer responds to commands, administrators can carry out a hard reboot via the control system for the power supply.
Out-of-band management allows admins to maintain components such as servers, network devices and power supply units and resolve malfunctions via remote access. If there is an issue with connectivity, out-of-band solutions offer a failover solution that is often via cellular (4G LTE or 3G) or via PSTN modem for sites outside of coverage.
Out-of-band management has advantages beyond urgent crises. It also makes it possible to identify and resolve issues automatically even before they affect local data traffic using an autoresponder system to rectify network failures by using diagnostic and repair aids for problems that occur frequently. Increasingly, out-of-band devices are connected to local sensors to monitor temperature, moisture, smoke, vibrations and local power conditions for preventive maintenance and rapid incident response.