Xu Min2020-06-08 7
The outbreak of COVID-19 has upended every aspect of daily life with millions forced to stay at home. And this drastic change is reflected in the statistics: on average, people are spending 21.5% more time on the Internet. The pandemic — and the associated steps taken by authorities to tackle it — has accelerated the digitization of the whole of society, as more and more people go online for an ever-increasing number of reasons and applications: from watching live broadcasts and short videos to e-commerce activity, playing interactive games, or deploying network technology for telemedicine, online education, remote office, big data, and Artificial Intelligence (AI). As a result, there has been a sharp increase in traffic between Data Centers (DCs), making Data Center Interconnect (DCI) the bottleneck that is hindering progress in improving the digital user experience.
According to the Global Interconnection Index report released by Equinix — the world’s largest data center and colocation provider — DCI bandwidth capacity is expected to reach 13,300 Tbit/s in 2022, representing a Compound Annual Growth Rate (CAGR) of 51%. Such a level of growth will be essential, as governments, finance, telecommunications, and other industries become increasingly dependent on the digital service ecosystem, driving demand for higher interconnection bandwidths.
Against this backdrop, the cost of DCI traffic has become a major challenge for enterprises. Private line fees have nearly doubled and have become a source of financial pressure. This not only limits the speed of digital transformation but also the ability of enterprises to deploy a wide range of applications. To tackle this issue, a growing number of enterprises are therefore turning to self-built DCIs, which offer faster Return on Investment (ROI) and a high-quality service experience.
Leased private lines incur monthly charges based on bandwidth. While prices may vary by location, generally speaking, 10G or 100G Wavelength Division Multiplexing (WDM)-based hard-pipe private lines are more expensive than IP-based Multiprotocol Label Switching (MPLS) private lines. Of course, self-built DCI requires start-up costs, including equipment Capital Expenditure (CAPEX), the fiber leasing, and subsequent Operating Expense (OPEX), such as equipment Operations and Maintenance (O&M), electricity fees, and possibly equipment room leasing.
The following table compares the cost of a private line to the cost of a self-built DCI, in a typical European city.
Private line leasing cost
|Private Line||Monthly Fee (USD)|
|1 x 10GE||2,500|
|1 x 100GE||20,000|
Self-built DCI cost = Equipment CAPEX + Fiber leasing + OPEX (space leasing/electricity fee/O&M)
|Self-Built DCI||Monthly Fee (USD)||One-Off Fee (USD)|
Based on these numbers, a self-built DCI with a bandwidth of 4 x 10 GE at 40 km breaks even in five months, while a bandwidth of 2 x 100 GE at 100 km shortens the breakeven point to just three months. Note that this is an estimate and costs may vary. In general, though, the higher the bandwidth, the sooner the self-built DCI will yield an ROI comparable to a leased private line.
In additional to financial advantages, self-built DCIs outperform private lines in terms of service provisioning efficiency, O&M quality, and the Service Level Agreement (SLA).
Both the commissioning and maintenance of traditional WDM transmission systems are complex: most IT teams are not up to the task and have to rely on the expertise of optical transmission engineers. In contrast, lightweight and high-capacity DCI devices with simplified deployment and O&M allow enterprises to build their own DCIs to meet their growing bandwidth requirements, accelerating digital transformation.
Increasing the per-fiber transmission capacity can also significantly reduce fiber leasing costs. This can be done by increasing the per-wavelength capacity and expanding the fiber spectrum. The per-wavelength capacity of DCI applications has evolved from 100/200 Gbit/s to 400/600 Gbit/s, and may even expand to 800 Gbit/s in 2020 or 2021. Furthermore, in order to achieve the optimal utilization of spectrum resources, the existing C band is extended to Super C band and C + L band, increasing attainable wavelengths from 80 to 220.
When it comes to deployment, there are two critical factors to consider. First, it's necessary to source the devices — including order placement, production, transportation, and receipt — which may take from several weeks to two months. The set-up phase is shorter, requiring between two days and several weeks, and involves equipment installation, configuration, commissioning, and acceptance. Industry leaders with mature manufacturing and supply chain capacity can certainly offer better products and solutions for enterprises. Moreover, a good product design that enables one-click provisioning can significantly speed up DCI deployment and support fast service expansion.
According to statistics by a large Over The Top (OTT) company in Asia, most issues on DCI networks are caused by (speaking approximately):
• Fiber link faults, such as interruption and jitter: 55%.
• Power supply, fan, and service board faults: 6%.
• Optical module faults: 4%.
• Other correlative alarms: 35%.
To fix these issues, enterprises need:
• Optical path fault prediction and proactive O&M; fiber fault detection and location.
• Alarm suppression to eliminate correlative alarms and ensure that only one alarm is generated for each fault; a triggered troubleshooting sequence that begins upon fault detection.
• Fast report and prediction of device faults.
• Simplified network management and lower technical knowledge requirements through What You See Is What You Get (WYSIWYG) functions.
As cloud-based applications evolve, enterprises have a greater need for DCIs. The path to growth is full of challenges, however. For example, when DCI bandwidth exceeds 100 Gbit/s, leasing costs will skyrocket. At the same time, most enterprises find it difficult to source the technical skills necessary for the complex maintenance of DCI during the construction period. In response, Huawei has launched an innovative DCI solution — Huawei OptiXtrans DC908 — to help enterprises handle growing bandwidth requirements and promote digital transformation, through lowering costs and providing far greater levels of assurance.