Autonomic Control Loop

• Monitor
• Aggregation
• Analyzer 
  

Automatic Layer







The autonomic manager can be regarded as the brain of the autonomic management framework
and plays a vital role in the provision of network intelligence. Taking advantage of cutting‐edge techniques
in the field of artificial intelligence, it provides the capabilities of self‐healing, self‐protection
and self‐optimization by means of reactively and proactively dealing with detected and predicted
network problems. the autonomic manager consists of the following
functional blocks:


A diagnoser is in charge of diagnosing the root cause of network problems.
The monitor can derive a symptom for each detected or predicted network problem from the collected sensor data. The diagnoser processes the reported symptom to make clear its reason,

and notifies the decision‐maker
decision-maker (DM) can decide a set of corrective or preventive tactics to deal with the network
problems based on incoming diagnostic information. A tactic is a high‐level description of a
countermeasure, which needs to be transferred into an implementable action;


An action enforcer (AE) is responsible for providing a consistent and coherent set of scheduled
actions to be enforced in the network infrastructure. For this purpose, this module recognizes and
validates these tactics by applying conflict detection and resolution in order to provide implementable
actions to be enforced.


Within this control loop, the metrics collected by the sensors are processed by the monitor module
first. Subsequent modules extract the required information from the previous module and provide
the next‐level results to the next module.
The information model associated with the autonomic
control loop is explained as follows:


Sensor data: A range of differentiated data sources can be expected to be identified in the
upcoming 5G infrastructure. All monitoring information retrieved from physical devices, UP,
SDN controller, SDN/NFV sensors, VIM etc., are uniformly referred to as sensor data. The monitor
is the corresponding module that is in charge of collecting sensor data from underlying
infrastructures;


Monitor data: The monitor regularly collects the sensor data and reports the necessary information
to the aggregator. Some of the data is periodically collected, which stands for either normal or
abnormal network behaviors;


Aggregated data bundle (ADB): The monitor data related to a network problem may be retrieved
from a set of sensors, rather than a single one. For example, in the case of a distributed denial of
service (DDoS) attack, the source and destinations are distributed. The raw information contained
in monitor data should be processed to produce aggregated and correlated information, which is
called aggregated data bundle;


Symptom: A high‐level health‐of‐network metric that may be derived from a set of correlated
alarms, events, KPIs, etc., that can be evaluated to indicate the characteristics of an existing or
emerging network problem, together with the additional contextual information such as metadata,
is defined as a symptom;


Performance: The report of achieved performance by an executed action is two‐fold: i) if an action
degrades performance rather than solving a problem, a roll‐back mechanism will be triggered to
recover the network status to the initial point before the action was performed; ii) the achieved
performance, which can be regarded as the benefit or reward of action. If a large extent of operational
data can be recorded, the network intelligence can be trained based on machine learning
techniques;


Cause: It is a description of what the reason of a network problem is or why a network problem
happens or will happen. Once the diagnoser receives a symptom, it diagnoses the cause of this
symptom;


Tactic: After the cause of a network problem is clarified, a countermeasure that can be applied to
tackle this problem needs to be decided by the decision‐maker. A tactic is a high‐level description
of a countermeasure, which is required to be transferred into an implementable action;


Action: This is an implementable version of a countermeasure with a description of how to enforce
this, taking into account available physical and virtualized resources. The action provided by the
AE contains more implementation details,