Which aspect does NOT contribute to network congestion issues?

Increased bandwidth availability does not contribute to network congestion issues because it directly enhances the capacity of the network to handle data traffic. When bandwidth is available in greater quantities, it allows more data to be transmitted simultaneously, effectively easing the flow of traffic and reducing the likelihood of congestion.

In contrast, high traffic volume on the network, slow processing speed of routers, and unoptimized routing protocols can lead to congestion. High traffic volume increases the demand for bandwidth, potentially exceeding available resources and causing delays. Slow processing speeds in routers can lead to bottlenecks as packets are queued waiting for processing. Unoptimized routing protocols may result in inefficient paths being taken by data, adding unnecessary hops and increasing overall latency. Each of these issues can exacerbate network congestion, making increased bandwidth a vital solution rather than a contributing factor.