· Link model: 100BaseTduplex link.
This is used to represent an Ethernet medium with a datatransmission rate of 100 Mbps. The following are the combination of networkdevices which can be connected together by using this link: hub, switch,station and bridge. It cannot be used to connect a hub to another hub. · Link model: PPP DS1duplex. This link model is used for connecting two IP based network devices.PPP DS1 operates at a data transmission rate of 1.
54 Mbps. · Application definitionobject: This configuration utility is used to specify applications whosetraffics will be generated in the network model. With this configurationutility, the name of an application and its corresponding description can becreated.
For instance, “Http(Light Browsing)” is a specification of a web (Http) application performing light browsing. · Profile definition object:In order to generate network traffic for each application specified in thenetwork, the profile definition object is used. Profile definition objectallows users to create profiles for each application they specified in theapplication definition object. Therefore to use this object, applications mustbe created using the application definition object. · Failure recovery utility:This object is used to mimic failure recovery scenario within a given networktopology. It has attributes that allow users to control the time and the statusof network objects such as links and nodes. The status of an object is either”fail” or “recover”. Status is measured in seconds.
Failure status indicateswhen the object should fail while the recovery status is used to indicate whenthe object should recover. Figure3.3 shows the internal infrastructure of the IT department subnet. The numberof network devices connected together in this subnet is the same as the othersubnets. However, it has five servers connected to the switch to support eachnetwork application.
These servers are database server, remote login server,file server, http server, and email server. These servers are connected to theswitch using 100BaseT duplex link.