Resources
Identity Use Cases & Scenarios.- FIDIS Deliverables.
- Identity of Identity.
- Interoperability.
- Profiling.
- Forensic Implications.
- HighTechID.
- D3.1: Overview on IMS.
- D3.2: A study on PKI and biometrics.
- D3.3: Study on Mobile Identity Management.
- D3.5: Workshop on ID-Documents.
- D3.6: Study on ID Documents.
- D3.7: A Structured Collection on RFID Literature.
- D3.8: Study on protocols with respect to identity and identification – an insight on network protocols and privacy-aware communication.
- D3.9: Study on the Impact of Trusted Computing on Identity and Identity Management.
- D3.10: Biometrics in identity management.
- D3.11: Report on the Maintenance of the IMS Database.
- D3.15: Report on the Maintenance of the ISM Database.
- D3.17: Identity Management Systems – recent developments.
- D12.1: Integrated Workshop on Emerging AmI Technologies.
- D12.2: Study on Emerging AmI Technologies.
- D12.3: A Holistic Privacy Framework for RFID Applications.
- D12.4: Integrated Workshop on Emerging AmI.
- D12.5: Use cases and scenarios of emerging technologies.
- D12.6: A Study on ICT Implants.
- D12.7: Identity-related Crime in Europe – Big Problem or Big Hype?.
- D12.10: Normality Mining: Results from a Tracking Study.
- Privacy and legal-social content.
- Mobility and Identity.
- Other.
- IDIS Journal.
- FIDIS Interactive.
- Press & Events.
- In-House Journal.
- Booklets
- Identity in a Networked World.
- Identity R/Evolution.
D3.8: Study on protocols with respect to identity and identification – an insight on network protocols and privacy-aware communication
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Title: PROTOCOL LAYERS |
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The ISO/OSI reference model, which is an abstract model to explain network architectures and protocol designs, defines seven protocol layers, which have different properties and functions.
The seven layers of the ISO/OSI model are:
Layer 7: Application layer
Layer 6: Presentation layer
Layer 5: Session layer
Layer 4: Transport layer
Layer 3: Network layer
Layer 2: Data link layer
Layer 1: Physical layer
The basic idea is that all layers are independent from each other, e.g., a protocol at layer 2 takes input from layer 3, processes this input and hands it down to layer 1, but the functions of layer 2 are independent of those of layer 1 and layer 3. The only requirement is an input/output of a well-defined form. Therefore the ISO/OSI reference model clearly defines specified interfaces (cf. Tanenbaum 2003).
Table : ISO/OSI reference model
The differentiation into the seven layers of the ISO/OSI reference model results in quite a complex protocol stack. The ISO/OSI reference model is well suited for teaching network designs but was never adopted in practice.
Today’s Internet architecture is based on the Internet reference model (also called TCP/IP model) which was developed before the ISO/OSI reference model and consists of only four layers. These layers are shown in Table 2.
Table : Internet reference (TCP/IP) model
To achieve just four layers the functionality of the presentation and session layers were combined into the application layer and the physical and data link layers were combined with the host-to-network layer. Note that the general specification of the host-to-network layer is rather vague in the TCP/IP reference model - it is just stated that a host needs somehow to be able to connect to a network and send IP packets.
Figure : Example illustrating the involved layers of the TCP/IP model on various stages of and end-to-end communication
Figure 1 illustrates the orchestration of the four layers of the Internet protocol stack to establish communication between a client (in this case a web browser) and a server (in this case a web server). In this case we have an exemplary HTTP request from a client to a server via two routers.
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