A.Most ISPs do not provide QoS for residential broadband. Asymmetric bandwidth reduces the chance of downstream congestion when traffic from Internet sites competes for bandwidth with IP voice traffic.
B.Additional downstream bandwidth compensates for insufficient upstream bandwidth. The aggregate bandwidth provides the same result. 
C.The additional bandwidth is needed to access more than one site. Most HTTP traffic is downstream. 
D.The additional downstream bandwidth allows the Enterprise VPN device to send the IP voice packets much faster, allowing them to reach the Teleworker network with less latency.