Delay Tolerant Networking

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Comparison between traditional IP protocol and delay-tolerant networking

The Delay Tolerant Networking (English for delay-tolerant network ; also Disruption-Tolerant Networking , for interruption-tolerant network , and shortly DTN is called) a protocol architecture to overcome the technical difficulties associated sparse and heterogeneous communication networks. The architecture is based on the Interplanetary Internet (IPN) developed by the US space agency NASA , but generalizes this design. In contrast to the design focus of the IPN - space communication - the DTN focuses on networks with low stability of the end-to-end connection.

development

At about the same time as the development of mobile ad-hoc routing procedures, DARPA commissioned NASA, MITER and others, independently of this, to develop a proposal for an interplanetary Internet (IPN) in the 1990s . A basic draft for an IPN architecture was presented by a group led by Vint Cerf , taking into account the susceptibility of network connections (packet corruption) in space and the necessary handling of long message delays (packet delay).

In 2002, Kevin Fall took up some of these ideas for the development of a generally interruption- tolerant network and presented his design under the title Delay Tolerant Networking and the acronym DTN derived from it at the SIGCOMM conference in 2003 . In the following years, the requirements for a corresponding network were discussed at various conferences that can also deal with long signal runtimes and connection interruptions. Experience with sensor networks and mobile ad-hoc routing processes should also be taken into account. The routing algorithms and procedures for ensuring the reliability and verifiability of the transmitted data have been improved over time.

In January 2017, researchers from McMurdo Station in Antarctica sent a selfie using the DTN protocol.

Routing

The transmission and routing of the information to be transmitted from the data source to the destination are a fundamental necessity in all data networks. DTNs differ from other data networks primarily in the lack of a permanent connection between data source and data destination. Ad-hoc routing procedures such as AODV and DSR could not be used under these conditions because they first try to determine the complete route from the source to the destination and only then transmit the data. However, if continuous end-to-end communication is difficult or impossible to ensure, the store and forward principle makes more sense. The data is transferred in small packets from one network participant to the nearest accessible network and is saved until the transfer to the target computer has been successfully confirmed. Transferring the same version of the message from source to destination in multiple ways is a common approach to increasing the likelihood of successful message transfer.

Bundle protocols

The RFC 4838 and RFC 5050 were published in 2007, they provide a necessary for the development of algorithms and applications overview of requirements for used in a DTN software. This protocol, generally referred to as the bundle protocol, defines a sequence of related data blocks as a bundle, with each bundle containing, in contrast to an individual data block, sufficient semantic information to continue an application. Bundles are between connected to the network node to the Store and forward transfer principle, as well different transport protocols can be used on the IP can be based protocol, but it does not provide. The protocol layers that transmit the bundles on your local network are called bundle convergence layers . The bundle architecture works like an overlay network ; it uses an additional name architecture based on endpoint identifiers (EIDs) and a rough class of service classification.

The bundle protocol must balance the different needs of individual applications for sending bundles over the network. Due to the store and forward nature of the DTN protocols, routing solutions benefit from the fact that information from the application level is known for routing. For example, the network can take into account when an application is dependent on receiving data particularly quickly, in one transmission or with a constant packet transit time.

Bundle protocols collect application data in bundles that can be transmitted over various networks with a high service priority . The service priority is generally specified by the application, the RFC 5050 Bundle Protocol Specification provides for the priority levels bulk , normal and expedited .

safety

Secure addressing is one of the key points of the bundle protocol.

The security requirements for a DTN network differ depending on the application and working environment, but authentication and confidentiality often play a major role. It is difficult to guarantee a certain level of security in a network without permanent connections, because cryptographic protocols or a key exchange become complex and there is a need for any network node to constantly recognize other network nodes that are only temporarily accessible in the network. The implemented solutions were often derived from mobile ad hoc network technologies and have been influenced by research on data security, such as the use of distributed certification authorities and PKI schemes. The application of ID-based cryptography, which enables network nodes to receive encrypted data with their public ID, originates from the DTN area itself.

Research approaches

The problems resulting from the requirements for the DTN are currently being investigated by various institutions

• The Delay Tolerant Networking Research Group .
• Technology and Infrastructure for Developing Regions project at UC Berkeley
• The KioskNet research project at the University of Waterloo .
• DieselNet research project at the University of Massachusetts , Amherst.
• ResiliNets Research Initiative at the University of Kansas and Lancaster University .
• Haggle research project of the European Union
• N4C research project FP7 of the European Union
• WNaN DARPA project

Some research projects on DTN for an Interplanetary Internet are already investigating the use of the Bundle Protocol in space:

• In 2008, the Saratoga project of the University of Surrey was the first to test the bundle protocol in space with the UK-DMC Disaster Monitoring Constellation satellite.
• NASA JPL 's Deep Impact Networking (DINET) experiment on board the Deep Impact / EPOXI spacecraft .

Web links

Commons : Delay-Tolerant Networking  - collection of pictures, videos and audio files

Individual evidence

1. ↑ A Delay-Tolerant Network Architecture for Challenged Internet , K. Fall, SIGCOMM, August 2003
2. ↑ Erin Mahoney: Antarctic Selfie's Journey to Space via Disruption Tolerant Networking. November 27, 2017, accessed January 20, 2020 . 
3. ^ C. Perkins, E. Royer: Ad-hoc on-demand distance vector routing . In: The Second IEEE Workshop on Mobile Computing Systems and Applications . 1999.
4. ↑ D. Johnson, D. Maltz: Dynamic source routing in ad hoc wireless networks . In: Kluwer Academic (Ed.): Mobile Computing . 1996, pp. 153-181.
5. ↑ John Burgess, Brian Gallagher, David Jensen, and Brian Neil Levine. MaxProp: Routing for vehicle-based disruption-tolerant networks. In Proc. IEEE INFOCOM, April 2006
6. ↑ Philo Juang, Hidekazu Oki, Yong Wang, Margaret Martonosi, Li Shiuan Peh, and Daniel Rubenstein. Energy-efficient computing for wildlife tracking: design tradeoffs and early experiences with zebranet. SIGOPS opera. Syst. Rev., 36 (5): 96-107, 2002
7. ↑ Augustin Chaintreau, Pan Hui, Jon Crowcroft, Christophe Diot, Richard Gass, and James Scott. Impact of human mobility on opportunistic forwarding algorithms. IEEE Transactions on Mobile Computing, 6 (6): 606-620, 2007
8. ^ Amin Vahdat, David Becker: Epidemic routing for partially connected ad hoc networks . In: Duke University (Ed.): Technical Report CS-2000-06 . 2000.
9. ^ "Anonymity and security in delay tolerant networks" A. Kate, G. Zaverucha, and U. Hengartner. 3rd International Conference on Security and Privacy in Communication Networks (SecureComm 2007)
10. ↑ "Security Considerations in Space and Delay Tolerant Networks" S. Farrell and V. Cahill. Proceedings of the 2nd IEEE International Conference on Space Mission Challenges for Information Technology
11. ^ "Practical security for disconnected nodes" Seth, A. Keshav, p. 1st IEEE ICNP Workshop on Secure Network Protocols (NPSec), 2005
12. ↑ Use of the Delay-Tolerant Networking Bundle Protocol from Space ( Memento of the original from May 13, 2008 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , L. Wood et al. , Conference paper IAC-08-B2.3.10, 59th International Astronautical Congress, Glasgow, September 2008  
13. ↑ UK-DMC satellite first to transfer sensor data from space using 'bundle' protocol ( memento of the original from April 26, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , press release, Surrey Satellite Technology Ltd , September 11, 2008 
14. ↑ CLEO Orbital Internet earns Time Magazine award ( Memento of the original from December 7, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Robin Wolstenholme, Surrey Satellite Technology Ltd space blog, November 14, 2008  
15. ^ A Better Network for Outer Space , Brittany Sauser, MIT Technology Review, Oct. 27, 2008
16. ↑ NASA Successfully Tests First Deep Space Internet , NASA press release 08-298, November 18, 2008