accounting
termnetworkinggovernance & risk
The third A in AAA: recording what an authenticated party actually did, for billing, capacity or evidence.
It is the one most often configured last and needed most under pressure, because authentication and authorisation answer questions about the present while accounting is the only one that answers questions about the past. In carrier networks it exists to produce an invoice; in enterprise networks it exists so that someone can say which account issued which command on which device, which is exactly the question asked after an outage or an intrusion and exactly the record nobody enabled.
Also known as: aaa