Term
| What are some RFCs on architectural principles produced by the IETF? |
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Definition
- General principles
- Transparency
- The "End-to-end" principle
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Term
| What are the general principles of the IETF in their RFCs? |
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Definition
- One IP protocol
- The "hourglass" model
- Exception: Migration towards a new version of IP
- Netwokr (IP) layer independent of hardware
- Allows IP to take advantage of new hardware
- Self healing network
- Implies adaptive routing protocols
- No centralised control
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Term
| Briefly, what is the "hourglass" model? |
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Definition
| The idea of funnelling all communications through some common, ubiquitous communications protocol - e.g. the IP and ATM |
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Term
| What are the design principles of the IETF in their RFCs? |
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Definition
- Support heterogenity
- If there's many ways of doing things, pick one
- Avoid duplication of same functionality
- Scale to millions of sites of many nodes
- Simplicity, modularity
- Standards based on running code
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Term
| What are the "other" principles of the IETF in their RFCs? |
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Definition
- Avoid hard-coding addresses
- Prefer unpatented technology
- Fully international
- Privacy and authenticity support desirable
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Term
| What are the transparency principles of the IETF in their RFCs? |
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Definition
- Single universal logical addressing scheme
- Packets flow from source to destination unaltered
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Term
| What are some examples of loss of transparency? |
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Definition
- Network address translation
- Translated private IP address space
- Short-term address leases via DHCP
- Application layer gateways and caches
- Split-view DNS
- Various load-balancing methods
- IP blacklists
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Term
| Some ways to restore transparency? |
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Definition
- IPv6 will remove the "need" for NAT or use of ambiguous private IP address space
- IPv6 will restore addressability if not connectivity
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Term
| What are the fundamentals of the "end-to-end" principle? |
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Definition
- Certain end-to-end functions can only be performed correctly by the end-systems
- Any network, however carefully designed, will be subject to failures of transmission at some statistically determined rate
- The best way to cope with failures is to accept them and give responsibility for the integrity of communication to the end systems
- Applies equally to end-to-end security
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