Multi-protocol label switching (MPLS) has a fast-reroute feature. How quickly can MPLS recover a connection after a loss of connectivity?

The correct answer highlights an important aspect of Multi-Protocol Label Switching (MPLS) technology, specifically regarding its fast-reroute capability. MPLS is designed to quickly recover from connectivity losses, which is critical in maintaining high levels of service and minimizing downtime in networks, especially those that require consistent and reliable data transmission.

The fast-reroute feature allows MPLS to quickly direct traffic through an alternative path when a primary link fails. Typically, the industry standard for MPLS fast reroute is around 50 milliseconds. This time frame represents a balance between efficiency and the complexity of rerouting packets. Within this period, MPLS can ensure that data packets are redirected along an established backup path, significantly reducing the impact of a failure on end users.

Setting the expectation at 50 milliseconds acknowledges the operational capabilities of MPLS in real-world scenarios, where service quality is critical, and delays can lead to significant issues, particularly in applications like voice, video, and gaming where low latency is paramount. While MPLS can certainly achieve quicker recovery times under ideal conditions, the established guideline helps in managing performance expectations and planning for network resilience.