Voice and video traffic is particularly sensitive
to measurements that the QoS feature shapes and controls, especially
latency and jitter. For voice and video transmissions to be audible
and clear, voice and video packets cannot be dropped, delayed, or
delivered inconsistently. A best practice for voice and video applications,
in addition to guaranteeing bandwidth, is to guarantee priority
to voice and video traffic.
In this example, employees at
a company branch office are experiencing difficulties and unreliability
in using video conferencing and Voice over IP (VoIP) technologies
to conduct business communications with other branch offices, with
partners, and with customers. An IT admin intends to implement QoS
in order to address these issues and ensure effective and reliable
business communication for the branch employees. Because the admin
wants to guarantee QoS to both incoming and outgoing network traffic,
he will enable QoS on both the firewall’s internal- and external-facing
interfaces.