1. Network Architecture
By Dr. Shadi Masadeh 1

2. Network Architecture Background What is network architecture?
In general, architecture is the art and science of designing and constructing, or the discipline dealing with the principles of design and building .
Network architecture Includes addressing and routing, network management, performance, and security. .

3. Network Architecture
What is network architecture? A more specific definition
Understanding of the relationships between (architectural) components of the network.
Network architecture guides the technical design of the network, through the application of high-level design principles to the network building blocks.

4. Network Architecture Building blocks might view as:
The physical entities (routers, switches, multiplexers, servers, etc.) in the network, or
Functional entities instead of physical entities. In doing so, the set of high-level design principles that constitute the network architecture is applied to how the network functions and operates.
Network functions are closely coupled to users, their applications, and their devices.
This allows user requirements to be directly represented in the network architecture.
Measures the network success, the success of a network can be defined by how well user, application, and device requirements are supported through these functions.

5. Architecture and Design
Architecture and design are similar in many ways, and designs are often just more detailed versions of the architecture.
Figure 5.1 compares some of the similarities and differences between architecture and design.

6. Architecture and Design
Architecture and design are similar in one important way:
they both attempt to solve multidimensional problems based on the results of the network analysis process. Figure 5.2 shows that a solution space can be made up of many variables (e.g., performance, security, and network management) and that network architecture solutions are based on relationships between these variables.

7. Architecture and Design
Network architecture describes relationships, between components.
Network design usually specifies technologies, protocols, and network devices
Architecture and design complement each other.
Another way that architecture can differ from design is in the need for location information.
Location is important for some parts of the architecture (e.g., external interfaces, locations of existing devices and applications),
Relationships between components are generally location independent.
Inserting location information into the network architecture can be constraining.
For a network design, location information is important. (In the design there is a sufficient amount of detail that locations play an important part of the decision-making process.)

8. Component Architectures
Component architecture is a description of how and where each function of a network is applied within that network.
It consists of a set of mechanisms (hardware and software) by which that function is applied to the network
Each function of a network represents a major capability of that network; four functions that are major capabilities of networks:
Addressing/routing
Network management
Performance
Security.
Other general functions, such as infrastructure and storage….

9. Component Architectures
Mechanisms are hardware and software that help a network to achieve each capability. See Figure 5.3

10. Component Architectures

11. Network Management Component Architecture
Network management is providing functions to control, plan, allocate, deploy, coordinate, and monitor network resources.
Network management is part of most or all of the network devices. such As, the network management architecture is important as it determines how and where management mechanisms are applied in the network.
Network management mechanisms include
monitoring and data collection; instrumentation to access, transfer, act upon, and modify data; device and service configuration; and data processing, display, and storage.

12. Reference Architecture
A reference architecture is a description of the complete network architecture and contains all of the component architectures (i.e., functions) being considered for that network.

13. Component Architectures

14. Component Architectures

15. Architectural Models
We have three types of architectural models are presented here:
topological models (geographical)
flow-based models (traffic flows)
functional models (features)

16. 1. Topological models There are two popular topological models:
LAN/MAN/WAN model .
Access/Distribution/Core model.

17. LAN/MAN/WAN
This model is simple and is based on the geographical and/or topological separation of networks.
For example, the LAN/MAN/WAN model is often used as a LAN/WAN model, or the LAN component is separated into campus, buildings, or even floors.

18. Access/Distribution/Core models
This model focuses on function instead of location.
can be used to reflect the behavior of the network at its access, distribution, and core areas.

19. The access area :
is closest to the users and their applications .
is where most traffic flows are sourced and sinked.
flows and requirements can be treated.
on an individual basis more easily than in the distribution and core areas.

20. The distribution area :
can also source and sink flows, but they are more likely to be to or from multiple-user devices, such as servers or specialized devices.
Few users are normally directly connected to the distribution area.

21. The core of the network :
is used for bulk transport of traffic.
flows are not usually sourced or sinked at the core.
any view of individual flows is lost at the core.

23. 2. Flow-Based Models

25. 3. Functional Models In this model we present : service-provider model
intranet/extranet model
end-to-end models.
The service-provider architectural model is based on service-provider functions,
focusing on privacy and security, service delivery to customers (users), and billing.
In this model, interactions between providers (the networks) and with users.

26. The intranet/extranet architectural model focuses on security and privacy, including
the separation of users, devices, and applications based on secure access. Note that in this model there can be several levels of hierarchy (security/privacy)

27. The end-to-end architectural model focuses on all components in the end to-end path of a traffic flow. This model is most closely aligned to the flow-based perspective of networking.