1. Lec4: TCP/IP, Network management model, Agent architectures
Organized by: Nada Alhirabi
NET 311
Lec4: TCP/IP, Network management model, Agent architectures
Some of the slides from : COMP4690, by Dr Xiaowen Chu, HKBU

2. Protocol Architecture
A protocol architecture is the layered structure of hardware and software that supports the exchange of data between systems and supports distributed applications, such as electronic mail and file transfer.
At each layer of a protocol architecture, one or more common protocols are implemented in communicating systems. Each protocol provides a set of rules for the exchange of data between systems.

3. OSI Reference Model OSI: Open System Interconnection A 7-layer model
Each layer performs a subset of the required communication functions
Each layer relies on the next lower layer to perform more primitive functions
Each layer provides services to the next higher layer
Changes in one layer should not require changes in other layers

4. OSI Reference Model
Application: supporting network applications - FTP, SMTP, HTTP, etc.
Presentation: handle different data representations (e.g., encryption)
Session: connections between apps
Transport: host-host - TCP, UDP
Network: routing of datagrams from source to dest - IP, routing protocols
Link: data transfer between adjacent network elements - PPP, Ethernet
Physical: bits “on the wire”
Application (7)
Presentation (6)
Session (5)
Transport (4)
Network (3)
Data link (2)
Physical (1)

5. OSI Layers Physical Data Link Physical interface between devices
Mechanical
Electrical
Functional
Procedural
Data Link
Means of activating, maintaining and deactivating a reliable link
Error detection and control
Higher layers may assume error free transmission

6. OSI Layers Network Transport Transport of information
Higher layers do not need to know about underlying technology
Not needed on direct links
Transport
Exchange of data between end systems
Error free
In sequence
No losses
No duplicates
Quality of service

7. OSI Layers Session Presentation Application
Control of dialogues between applications
Dialogue discipline
Grouping
Recovery
Presentation
Data formats and coding
Data compression
Encryption
Application
Means for applications to access OSI environment

8. TCP/IP Protocol Architecture
Developed by the US Defense Advanced Research Project Agency (DARPA) for its packet switched network (ARPANET)
Used by the global Internet
No official model but a working one.
Application layer
Transport layer
Internet layer (or Network Layer)
Network access layer (or Link Layer)
Physical layer

9. TCP/IP Protocol Architecture
COMP4690, by Dr Xiaowen Chu, HKBU

10. TCP/IP Protocols
COMP4690, by Dr Xiaowen Chu, HKBU

11. OSI vs. TCP/IP
COMP4690, by Dr Xiaowen Chu, HKBU

12. TCP/IP An important protocol used widely on the Internet
A routable protocol
Supports communication with UNIX networks or any other network that work under the TCP/IP protocol
The base protocol in UNIX networks is TCP/IP
Can be used for configuring peer-to-peer as well as client-server networks of very large scale

13. A TCP/IP Application Scenario
Lab
The
Internet
Workstation
Internet
Router
Local
Router
Workstation
Configure the workstation for Internet access by
Installing TCP/IP.

14. Basic TCP/IP Installation and Configuration
Module
Basic TCP/IP Installation and Configuration

15. TCP/IP Installation and Configuration
A two-step process
First, install the protocol
With many modern OSs such as Windows XP, it is automatically installed
Second, configure its properties
When TCP/IP is automatically installed, the properties are set to be obtained from a DHCP server
However, it is also possible to manually set the properties

16. TCP/IP Installation Steps
Start
Choose Network/
Properties
From Network
Neighborhood/
Properties.
Install Protocol
TCP/IP
protocol
installed.
Add OK
End
Choose TCP/IP

17. Accessing the Window for TCP/IP Properties
Under different Windows operating systems the TCP/IP properties are accessed in different ways
The best and the most consistent way to access TCP/IP properties Windows is to go through the Control Panel and then select the Network Icon
Another way to access the properties is to go through Network Neighborhood
Thereafter, select the network properties (Based on the NIC) and then then continue to select the TCP/IP properties

18. Accessing TCP/IP Properties Tab
Start
Choose Network
From Network
Neighborhood/
Properties.
TCP/IP/
Properties
Proceed
Define TCP/IP properties

19. Network Models

20. Architectural models for network management
Network management architecture consists of three sections:
Centralized:
Consists of a key management station.
Hierarchical :
Consists of one main station at the center and various management stations distributed among the systems.
Distributed:
Consists of various stations for network management
Distributed based on the geographic distance or function.

21. Centralized Management Model
It is defined as a single network management system that runs network management applications and all the information are stored in a single centralized database.
Examples:
Open view (hp)
net view (IBM)
Sepctrum NM NM
Network Management system
Network Resource

22. Network Management Configuration
Centralized vs distributed
Centralized configuration
COMP4690, by Dr Xiaowen Chu, HKBU

23. Network Management Configuration
Centralized configuration
One management station hosts NMS
Remote monitors/probes on LAN segments
Advantage: NMS has complete view
Disadvantage: single point of failure
COMP4690, by Dr Xiaowen Chu, HKBU

24. Advantages of the Centralized Management Model
Facilitates decision making.
Only single place is determined for network management.
Easy access to the centralized database.
Easy to expand and maintain the network.
Highly secure.

25. Disadvantages of the Centralized Management Model
In the case of failure in the network management, all the related network management systems will fail.
Overloading the network management system due to the large amount of the exchanged information.

26. Network Management system
Hierarchical model
Hierarchical model is defined as a single network management system that manages various smaller network management systems that control network resources.
Examples:
Open view (hp)
Cisco NM NM NM NM
Network Management system
Network Resource

27. B. Hierarchical Model (Cont.)
Advantages:
Distributing the load of the network.
Distributing the load of managing the network.
Bringing the network management systems closer to the managed network resources
Disadvantages:
High cost.
Complicated and difficult in connection.

28. Distributed Management Model
In this model network management systems are distributed on different indeterminate and in dependable places.
Examples:
CORBA(NCR)
DCOM(Microsoft) NM NM NM NM NM
Network Management system

29. Network Management Configuration
Distributed configuration
Each LAN has its own management station and a simple NMS
One mgmt station/NMS manages the backbone and coordinates local NMSs
Advantage: robust in case of failure
Disadvantage: complexity, coordination

30. Network Management Configuration
Distributed configuration
COMP4690, by Dr Xiaowen Chu, HKBU

31. Distributed Management Model (Cont.)
Advantages:
Distributing the load on the entire network completely.
Easy to expand the network.
Reliable and consistent.
Disadvantages:
Very complicated.
International standards are not yet defined.
Low security.

32. Network Management Model
Manager
Management Stations
Instructions
Alerts
Agent
Managed Entity
Resources
MIB
Management Information Base

33. Network Management Model (Cont.)
Manager: A program that receives alerts from agents and sends instructions to them.
Agents: A functional unit (Programs) located inside the managed devices (network resources) and provide management information to the devices and receives instructions to reconfigure the devices.

34. Network Management Model (Cont.)
Managed Entity: The network devices (resources) that is managed and controlled.
Management Information Base (MIB): A database of managed entities (resources) in the network and how they are accessed.
Example:
Remote Monitoring (Rmon)
One of the most famous MIBs (management information bases)
Used to monitor all the different components of LAN networks