A major media company recently deployed a new converged network. The original network design used separate networks for graphics and video, interactive data, and voice. The company has been experiencing problems with voice traffic in the new converged network. Most of the time voice quality is perfectly acceptable. Periodically voice quality exhibits unacceptable choppy voice signals, and occasionally calls are dropped. At this time the company is not willing to simply add bandwidth to the network.

Which QoS solution would most likely help to resolve the problem?

A.
Use TCP header compression and LFI to reduce delays.

B.
Prioritize voice traffic as the highest priority to ensure that voice traffic is always serviced by the priority queue.

C.
Use advanced technologies to compress all video and graphics traffic on the network.

D.
Use class-based weighted fair queuing to prioritize voice traffic with a higher weight than all other traffic.

Explanation:

The need to prioritize packets arises from the diverse mixture of protocols and their associated behaviors found in the data networks of today. Different types of traffic that share a data path through the network can impact each other.
Depending on the application and overall bandwidth, users may perceive performance degradation. Interactive audio data is delay sensitive, and transaction-based applications may require a higher priority than a file transfer. Videoconferencing requires a specified amount of bandwidth for acceptable performance. If the network is designed so that multiple protocols share a single data path between routers, prioritization may be necessary at the congestion points. Prioritization is most effective on WAN links where the combination of traffic bursts and relatively lower data rates can cause temporary congestion. Depending on the average packet size, prioritization is most effective when applied to links at T1/E1 bandwidth speeds or lower. If there is no congestion on the WAN link, traffic prioritization is not necessary. If a WAN link is constantly congested, traffic prioritization may not resolve the problem. Adding bandwidth might be the appropriate solution.