TISGraph ist ein dokumentenzentriertes und modulares Reporting-Tool für Zeitreihendaten.

Highly Available Multi-Protocol Dispatcher

HA-Dispatcher is a turnkey software solution for driving large-scale deployments of GPRS-devices as part of RUC or Smart Grid infrastructures.

  • Up to 1 million deployed devices
  • Up to 20.000 simultaneously connected devices
  • Verified by a comprehensive test-suite
  • Integrated Lifecycle Management
  • Customizable Backoffice Interface
  • Consulting, Site-Planning

Software Design

HA-Dispatcher’s components at a glance.

Multi-Protocol TCP/IP based Dispatcher

  • Fully customizable communication protocol
  • Supports multiple protocols on different ports simultaneously
  • Different protocol versions on a single port
  • SATCOM Interface (IRIDIUM, Thuraya)

Non-Blocking Multiplexer

  • Geared towards modern multi-core processor architectures
  • Configurable number of working threads
  • Minimal amount of context switches
  • Configurable maximum number of concurrent connections
  • Guarantees utmost robustness

Clustering

  • Ready for clustered deployment by using latest JBOSS® technologies
  • Integration with standard load-balancing technologies like HAproxy
  • Scales above 20.000 concurrent GPRS-connections

Datacenter Integration

  • Independent from database servers through the use of JDBC and JPA
  • Prepared for multi-carrier environments for maximum leverage in DDoS-Prevention

Customizable Layering Technology

  • Security, filtering, logging, …
  • Hot-plug additional layers
  • Prepared for a large variety of authentication and encryption schemes

Scalability Test

ev-i’s HA‑dispatcher builds on over 2 years of practical experience with several EFC client protocols in various customer projects. The codebase of HA‑dispatcher was designed from scratch, and permits the integration of customer-specified protocols in a minimal amount of time.
In its latest revision the code was subject to a series of scalability test on a 3‑node dual‑core JBOSS‑cluster to prove the basic design principals.

Result of the Scalability Test showing linear growth of session time

The illustration shows the results of the scalability test utilizing a test client inserting 10 fee transactions per device in each session, while establishing a uniquely associated TCP/IP connection for each session.

The test shows that the average number of fee transactions inserted into the database is nearly constant for up to 7000 concurrent TCP/IP connections. As a consequence the session time for each client shows a linear growth with the number of concurrent clients.

Additional Modules

The modular design of ha-dispatcher enables project-specific plugins to provide additional features such as dynamic pricing schemes or map-matching.

Map Matching

Map Matching based on TeleAtlas data

As part of two customer projects, a map matching module has been developed, which enables tracing a vehicle’s path based on raw GPS data.

Binary Space Partitioning of road links

Based on a binary space partitioning graph shown in the above illustration, the map-matching module is able to find the appropriate road link to a GPS position. Combined with GPS bearing information and a tracing algorithm, the exact distance and topology of the used road links may be determined based on the GPS track of an On Board Unit.

Security

ha-dispatcher features a pluggable security layer, with the following highlights:

  • state of the art TLS-1.2 implementation
  • preshared key (RFC4279) or X.509 certificate key agreement
  • GCM modes (NIST SP800-38D, RFC5288) for symmetric encryption

This set of algorithms allows the implementation of a lightweight TLS stack on the client side, which minimizes power consumption and software complexity on embedded devices as outlined in the schematic TLS handshake below compared to the full certificate based handshake from a standard TLS handshake.

A TLS handshake making use of preshared keys.
(Licensed under the FDL, based on material from https://de.wikipedia.org)

A TLS handshake using X509 certificates.
(Licensed under the FDL, material from https://de.wikipedia.org)

Consulting

HA-Dispatcher was developed with experience gained in more than four years of work in the field of road pricing systems.

Being involved in a wide variety of aspects concerning road pricing in different countries gave us expertise which we are happy to share with our customers. As a project partner we offer you our experience in the following fields:

  • Protocol Design
  • Infrastructure Planning (Server Sizing, Bandwidth estimations)
  • Integration & Robustness Testing
  • Deployment of load balancers
  • Firewall Setup
  • Change Management (Software Updates, deployment of Future Protocol Versions)

We believe that a robust and long-lived DataCenter infrastructure is the sum of many small and interacting parts. Therefore we are committed to an integrated view on the infrastructure — from protocol design to real-world performance tests.

This approach empowers our customers to achieve a maximum of reliability and sustainability for minimum infrastructure costs.

References

  • Dutch National Roadpricing Research Trial
  • TFL – Traffic for London Phase I
  • SISTER
  • Electronic Tolling Back Office – Demonstrator (EFKON / IBM)
  • Spitsmijden Brabant – Mobility Project in The Netherlands with 5000 OBUs deployed.