I'll arbitrarily divide them into four areas: failures, network issues not within the direct control of service provider, denial of service, and scheduled maintenance.

我将随意将它们分为四类：故障、不受服务提供者直接控制的网络问题、拒绝服务和预订的维护。

youdao

Generally, an application can create event listeners with event handlers through multiple connection ports, but this is costly in terms of network resources and maintenance.

通常，应用程序可以通过多个连接端口用事件处理程序创建事件侦听程序，但是这在网络资源和维护方面花费较大。

youdao

The second soft goal specifies exceptions, such as planned failures, denial of service, scheduled maintenance, network outages, and network issues within the control of a service provider.

第二个软目标指定异常，例如计划的故障、拒绝服务、计划的维护、网络中断和服务提供商控制内的网络问题。

youdao

Hosting services from the likes of Microsoft (Azure) and IBM (SmartCloud) are perfect for eliminating the physical maintenance of a network infrastructure.

FORBES: Connect

How much loyalty or protection of national security will we get from an overseas maintenance center which has full access to our network and all sensitive portions of it?

FORBES: Verizon Strike Highlights Weakness in Wireline Business

Verizon has been replacing high-maintenance portions of its residential copper network with fiber optics to provide enhanced services and to reduce ongoing repair costs.

ENGADGET: Verizon adds 'record-high' 2.1 million subscribers in Q4 2012, but still makes a loss