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Downtime: a word to strike fear into the heart of any IT manager. Network interruptions are the biggest cause of ICT outages. Just think about it: your apps, servers and even devices might be functioning perfectly, but without a network to communicate via, your systems are impaired.


According to some estimates, 89 per cent of firms had at least one unplanned outage in 2016, while 69 per cent suffered two or more.

Major costs

The direct costs from network outages include lost employee productivity and possible regulatory fines to costs associated with any resulting IT investigation. There’s also a direct revenue impact from the potentially massive hit to the organisation’s reputation, including customer attrition and share price.

The recent ICT incident at British Airways illustrates the potentially catastrophic repercussions of a simple network outage. A suspected power surge at a UK datacentre damaged servers and had a disastrous knock-on effect, taking out check-in and other operational facilities. It left planes grounded, tens of thousands stranded for days and may have cost the airline as much as £80 million in lost revenue, passenger compensation and other costs.

Every incident is different, but IHS estimates ICT downtime costs North American organisations $1 million a year for an average mid-size company, and over $60 million for a large organisation. Separate data from IDC claims unplanned app downtime – potentially resulting from network outages – costs Fortune 1000 firms up to $2.5 billion every year. Meanwhile, Blue Wireless founder Ivan Landen estimates network downtime costs can range “from $500/hr for when a few people are sitting idle, to $100,000/hr when it impacts business logistics, customer transactions, etc.”

Top causes of network outage

So what are the main reasons behind a typical network outage? They can be broadly grouped into a few basic categories:

1. Human error: Rumours are that this had a part to play in the BA outage. Networks are complicated systems where too many manual processes can introduce errors in configuration and the like.

2. Power failure: Reportedly the main culprit behind BA’s woes, this can occur as a result of environmental issues like lightning strikes as well as problems with fans, capacitors, control ICs and power components.

3. Security: Failure to patch software and firmware properly can lead to network outages, while , designed to overload pipes and take entire organisations offline.

4. Hardware: Probably the main cause of network issues, and will only get worse as kit gets older.

5. Link failure: Fixed infrastructure is exposed to physical damage, which can lead to outages and congestion.

How to mitigate network risk

Now that we understand the main causes of network downtime, how do IT managers mitigate risk to keep vital systems up and running? Key investments should include:

  • DDoS mitigation service.
  • Network failover service, with wireless (3/4G) in case fixed infrastructure fails.
  • Network monitoring to spot early signs of failure.
  • Reviews of any network changes.
  • Switching to  (SDN) to ease network management and reduce manual error.

In the end, the right strategy will very much depend on your organisation, budget and resources. But given the increasing reputational and financial impact of outages, IT leaders must address any issues upfront before they have a chance to escalate.