Information Technology Reference
In-Depth Information
so on. The local knowledge is used to produce, identify and deliver monitoring
information.
Term 3
:
Information Coverage
. Given a monitor
M
and a piece of mon-
itoring information
I
i
,if
I
i
is included in the
I
M
of
M
,
M
is covered by
I
i
.
Term 4
:
Effective Coverage
/
Ineffective Coverage
. Given a monitor
M
I
,
and a piece of monitoring information
I
,if
M
I
receives
I
and benefits from it, it
is an effective coverage, nor it is an ineffective coverage.
Term 5
:
Maximum Effective Coverage
. Given a piece of monitoring in-
formation
I
and a monitor set
S
=
M
1
,
M
2
,,
M
n
, if and only if every monitor
of
S
is effective covered by information
I
, it is a maximum effective coverage.
Term 6
:
Routing Correlative
. Given two BGP routes
R
A
,
R
B
and cor-
responding monitoring information
I
A
and
I
B
, if any condition as follows is
satisfied,
I
A
and
I
B
are routing correlated.
a) The IP prefix of
R
A
and
R
B
belong to the same AS;
b) The AS-PATH property of
R
A
and
R
B
share the common sub-path;
Being similar with the topology of Internet, all of the AS monitors are widely
distributed and lacking of global view for information requirement, monitor only
coordinates closely with a subset of the rest monitor.Considering these charac-
teristics,the key issue of node coordination is how to share information. The
objective of CoISM can be described as follows: For a given monitor set
S
M
=
{
, how to realize maxi-
mum effective coverage for
S
I
with low computing and communication cost.
M
1
,
M
2
,,
M
n
}
and a series of information
S
I
=
{
I
1
,,
I
m
}
3 Cooperative Validating BGP
3.1 Algorithm
Geoffrey G. proposed an origin and path validation method IRV [15]. In their
study, BGP monitor sends query message to other ASes monitor one by one
which are included in AS-PATH. Geoffreys method proposed a cooperative mon-
itoring method but did not consider blind spot and linearity increasing commu-
nication cost.
3
1,2,3
1
2
A
B
C
A
B
C
R
1
P
1
:{E,F}
R
1
P
1
:{E,F}
1,2,3
R
2
P
1
:{E,B,F}
1,2,3
P
1
:{F}
R
2
P
1
:{E,B,F}
P
1
:{F}
R
3
P
1
:{E,C,F}
R
3
P
1
:{E,C,F}
P
1
P1
E
F
E
F
(a)Validation Process of IRV
(b)Validation Process of CoISM
(a)Validation Process of IRV
(b)Validation Process ofCoISM
Provider-Customer
Peering-Peering
BGP route
Message flow
Fig. 2.
Route validation process of IRV and CoISM
