What should a network engineer be most concerned about when ensuring load capacity to a backup site's WAN connection?

A network engineer should primarily focus on peak capacity when ensuring load capacity to a backup site's WAN connection. Peak capacity refers to the maximum amount of traffic that can be handled by the WAN link during times of highest demand. It is crucial for maintaining performance and reliability during critical periods, especially when backup systems are activated.

Understanding peak capacity helps engineers ensure that the WAN connection can accommodate sudden spikes in data traffic. This is particularly important in scenarios where the primary site experiences disruptions, and backups need to seamlessly take over. If the capacity during peak times is not adequately addressed, it could lead to poor performance, latency, or even outages, undermining the purpose of having a backup site.

In contrast, while traffic normalization, quality of service (QoS), and concerns regarding packet loss and jitter are all important considerations for network performance, they serve more as adjustments or mitigations rather than the foundational concern regarding the ability of the WAN link to handle critical loads. Peak capacity specifically addresses the ability of the backup site's WAN to perform under demand, which is essential for maintaining service continuity.