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Collaboration, Voice & AV · Foundational

Telephony Class of Service

In telephony, the set of destinations and features a user or device is allowed to reach, enforced with partitions and CSSs.

Definition

Class of service policies separate users such as lobby phones, standard employees and executives by what they can dial: internal only, local, long distance, international or premium numbers. In CUCM CoS is built with partitions, CSSs, blocking patterns, Forced Authorization Codes and time-of-day routing. In networking, Class of Service also refers to the 802.1p priority field, which is a different concept.

Example

Executives get a CSS that includes PT-International; staff do not.

Exam tip

Read questions carefully: telephony CoS is calling permissions, while Layer 2 CoS is the 802.1p priority value.

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