Information Technology Reference
In-Depth Information
organisation of etiquette based on community context. Section four summarises our
main claims.
2 Functional Models
2.1 Design Considerations
We treat the self-* requirement as a meta-level non-functional one that supersedes
other, often overlooked non-functional requirements such as security, manageability,
and testing. By this we avoid partitioning of a system under design into separately
handled concerns that later might require integration. Also, possible replication of
features might be avoided. Finally, we hopefully meet all other non-functional re-
quirements within the same design paradigm.
The most benefits can be achieved at the finest possible granularity of node's func-
tion. Following the traditional telecommunication definition of a functionality found
in [8] we model node's function
F
as a triple
F= <component, resources, controls>, (1)
where
component
is to denote the identity of autonomic node, device or functionality
that hosts internal
resources
with local
controls,
we assume that local controls are
represented by fully specified policies (see section 3.2). Inputs for
F
are media and
media signalling; usually signalling inputs are destined to local controls, while media
inputs are resource requests. Both inputs might have certain safeguards, preventing
known to be unwanted inputs. An example of media safeguard is filtering of so called
Martian addresses on router interface; an example of media signalling safeguard is
filtering of attempts to contact network side signalling agents by non-authenticated
roaming signalling user agents [9]. SMTP filtering of spam messages differs from the
above examples in one important respect — it learns, but the process of learning is
typically under the governance of a human [10]. There are also two types of outputs
of
F —
media and its signalling, with optional safeguards on outputs, e.g. to ensure in-
profile transmission of outbound media.
Functional safeguards play paramount role in the proposed cooperative defence of
the infrastructure: locally triggered safeguard is an important source of vulnerability
information that cooperating entities learn from the workflow and use for pressing
back at potential attacker.
2.2 Node Model
Without loss of generality we model any network node media or media signalling
function as an input-output relay with possible transformation. We no longer distin-
guish between media and media signalling, the both types of payloads will be treated
as media, contrary to a new type of communication we aim to design. Thus, we can
conceptually represent all node's functionality as a matrix (2)
(2)
Φ
=
F
ij
,
i
=
1
n
,
;
j
=
1
m
,
,
