Name the type of communication in which the persons of two departments

Name the type of communication in which the persons of two departments, one at higher position and another at lower position, communicate with each other. State some of its advantages also.

It is a diagonal form of formal communication. Advantages of formal communication are:
(i) It is systematic. It ensures orderly flow of information and ideas.
(ii) It provides support to the authority of superiors over their subordinates.
(iii) The source of formal communication can be easily located.
(iv) Responsibility for actions, taken on its basis can be easily fixed.
(v) It helps in coordination of activities and efforts.