To support partitioning, the model must define
the mappings between the different levels of par-
titioning.
An important property of contained subnetworks
is that they may span multiple physical loca-
tions.
Routing tables may be defined for containing
subnetworks the same way as was done for
the subnetwork representing a single router.
2.4 The Traffic Trunk
Traffic in the context dealt with here is either
planned traffic for which network capacity must
be calculated, measured traffic that needs analy-
sis to explain the observed behaviour, or real
traffic in an operational network.
Traffic is carried by unidirectional packets, each
comprised by an IP header and an amount of
data. A flow is a unidirectional stream of pack-
ets, distributed over time. It may have a very
fine granularity reflecting a single interchange
between hosts. These single interchanges are
often called micro-flows. The aggregated flow
is a number of flows that share forwarding state
and a consistent resource reservation along a
sequence of routers. The route of a flow across a
subnetwork is an ordered list of CPGs at the next
lower level of partitioning.
The traffic trunk is an abstract description of
packet traffic. According to the definition in
[PASTE], it constitutes a number of flows aggre-
gated according to their traffic class (DiffServ-
class) and placed inside an LSP together with
zero (L-LSPs) or more (E-LSPs) other traffic
trunks of different class.
The overall traffic requirements for the network
in question is represented jointly in [TE_REQ]
by the combination of the properties of the traf-
fic trunks, topological constraints and the capa-
bilities of the other routing protocols involved
on layer 3 (IGP-oriented).2.4.1 The Traffic Trunk Model
The properties of the traffic trunk may be
expressed in terms of an object containing oper-
ations and attributes as described below.TrafficTrunk “myGoodFriend”{
OPERATIONS {
Establish( );
“An instance of a traffic trunk is
created using this operation.”
Activate( );
“To cause the traffic trunk carrying
traffic.”
Deactivate( );
“To stop a trunk carrying traffic.”
Modify( );
“To allow traffic trunk attributes
being modified.”
Reroute( );
“To reroute a traffic trunk.”
Destroy( );
“To delete a traffic trunk including
the release of all resources allocated
to it, such as label space and
available bandwidth.”
};
ATTRIBUTES {
TrafficClass;
“This is the traffic class according to
the DiffServ classification.”
DSCP;
“This is the DiffServ Code Point of
the traffic class.”Figure 6 Network topologySubnetworkSubnetworkCPG
SubnetworkCPGCPGSubnetworkCPGCPGCPG CPGCPG
CPGCPGCPGCPGCPGLink
LinkLink