Flow Networking in Grid Simulations - Grid Computing: Infrastructure, Service, and Applications - page 379

At a basic level, all components in GridSim communicate with each other
through message passing operations dei ned by SimJava. The second layer
models the core elements of the distributed infrastructure, namely grid
resources such as clusters, storage repositories, and network links. These
core components are absolutely essential to create simulations in GridSim.
The third and fourth layers are concerned with modeling and simulation
of services specii c to computational and data grids [4], respectively. Some
of the services provide functions common to both types of grids such as
information about available resources and managing job submission.
From a networking perspective, the current version supports packet-
based routing including background network trafi c modeling based on a
probabilistic distribution [6]. This is useful for simulating data-intensive
jobs over a public network where the network is congested. The limita-
tions of this network model are highlighted in the next section.

15.3 The GridSim Packet Networking Architecture
A typical dog-bone topology is shown in Figure 15.2 for a GridSim
experiment using the existing packet-level network framework. Consider
a user at user node 1 that wishes to send a 10 Mb i le to resource node 6.
In the current GridSim network model [6], the i le would be packetized
into MTU-sized packets by the Output class of the NetUser GridSim
entity and sent over the links. Every packet but the last is an empty

I
O

I

NetUser
1

Resource
5

O

SimpleLink SimpleLink

RIPRouter
3

RIPRouter
4

SimpleLink

SimpleLink SimpleLink

I I

NetUser
2

Resource
6

FIFOScheduler

FIFOScheduler

O O

FIGURE 15.2 GridSim packet networking architecture.