- Student: Dizhi Zhou
- Mentors: : Tommaso Pecorella, Luca Simone Ronga
- Abstract: this project aims to implement the bundle protocol (BP) in NS-3 which includes the bundle node structure and basic function of BP protocol. It is designed to support BP in IETF and CCSDS standard. First, the bundle node is the node installing bundle layer between application layer and transport layer in NS-3. The bundle node structure in this project is designed to be easily run on varied transport layer protocols and provides a unified socket interface to applications. Second, the basic functions of BP protocol are divided into three parts in this project: bundle transmission operations, custody signal support and bundle status report support(optional). This project also includes the test suites and documentations in BP.
- About me: I'm a Ph.D. student in the University of New Brunswick, Canada. My research interests include Multipath TCP (MPTCP) in cooperative wireless network and network simulation. You can find more information about my research in website or LinkedIn.
Bundle protocol structure
The bundle protocol (BP) can be seen as a special application, which provides transport layer services to other applications in a delay-tolerant network. In BP, we call packets as bundle and the node having BP layer as bundle node. The class structure of BP in NS-3 is shown below:
applications | ----------------------------------------- | | | | BundleProtocol | | | | | BpClaProtocol ---- BpRoutingProtocol | | | | ----------------------------------------- | Sockets
The rectangle area shows the main classes of BP in NS-3. BundleProtocol class implement several APIs to applications, such as Register (), Open (), Bind () and so on. Applications can use these APIs to transmit bundles between bundle nodes.
BpClaProtocol class is a pure abstract class which defines the internal APIs between the convergence layer adapter (CLA) and BundleProtocol. For different transport layer protocol, different inherited class must be created based on BpClaProtocol. In the current version, only BpTcpClaProtocol is implemented. It uses TCP socket in the transport layer to transmit bundles.
BpRoutingProtocol class is a pure abstract class which defines the APIs of bundle routing protocol. In the current version, only BpStaticRoutingProtocol is implemented, which uses a static map between local endpoint id and internet socket address.
Bundle protocol APIs
The Open () API installs the BundleProtocol and BpClaProtocol classes into a bundle node. It must be called in the first when user uses bundle protocol in NS-3..
Register method adds an entry in the persistent registration storage. A registration is indexed by the local endpoint id. If the state field in the register information is "true" (active) state, which means that this application desires to receive bundles, Register () triggers the BpClaProtocol to enable a transport layer connection to receive packet (e.g., listen state in TCP).
Bind () APIs set the registration state of the local endpoint id to "true". If the state in Register () is "true" already, Bind () should not be called.
Send a bundle from the source endpoint id to the destination endpoint id. The bundle will be stored in persistent bundle storage in BundleProtocol first. Once the transport layer connection is available, the BpClaProtocol will retrieve the first bundle in the queue and send it.
Applications can use this API to get bundles stored in BundleProtocol.
Build an endpoint id for a registration. In BP of NS-3, each registration has a unique endpoint id.
I divide the functions in this project into three parts:
- S1: functions to make sure the bundle can be sent from sender to receiver, node structure, send/receive/forward, static routing, naming syntax.
- S2: control functions for custody transfer, custody signal in AA.
- S3: error control signals: bundle status report.
This project aims to achieve following milestones:
12 weeks from Sep.4 to Nov.24:
- Week1: node structure: the class relationship in NS-3.
- Week2: node structure: the class relationship in NS-3.
- Week3: send and receive without forwarding procedure (two bundle nodes case).
- Week4: send and receive with forwarding procedure (three or more bundle nodes case, forward immediately, not custody transfer scheme).
- Week5: send and receive with forwarding procedure (three or more bundle nodes case, forward immediately, not custody transfer scheme).
- Week6: write test code and documentation for S1.
- Week7: custody signal support (store-and-forward, custody transfer).
- Week8: custody signal support (store-and-forward, custody transfer).
- Week8: write test code and documentation for S2.
- Week9: bundle status support* Week10: bundle status support.
- Week11: write test code and documentation for S3.
- Week12: wrap up.
I would like to express my special thanks of gratitude to Tommaso Pecorella and Tom Henderson, also thanks of Lalith Suresh and Luca Simone Ronga. Thanks for their valuable comments and helps on my work. Thanks for all mentors in NS-3 community to give me this opportunity in SOCIS project.