1.6.6. Networking¶

1.6.6.1. TCP/UDP Ports¶

1.6.6.2. Overview¶

DS provides a robust TCP based networking to distribute data to either DR clients or to user developed clients that make use of the DS networking API. The networking protocol is design to dynamically adapt the transmitted data rate (per client) based on a composite of network bandwidth, client processing power and client application performance. The effect of this is that a client can expect to receive data at a rate the will accommodate the performance of the entire data flow path. The typical limiter of the data rate is the network bandwidth; given sufficient bandwidth and processing performance by the client it is possible to receive all data from DS. This would allow users to write custom programs, using the DS API, and have the ability to capture, process and record all time domain data. The DR application uses this same protocol to receive data from DS. The plot update rate of a DR client is dependent on the available network bandwidth, the performance of the system and the performance of the DR application specifically, plots.

1.6.6.3. Robustness¶

Previous version of EDAS-ds ( <= 2.94 ) used multicast based networking to distribute data. The DS 3 series completely ditched multicast and has a brand new TCP based implementation to distribute data. The primary failing of the multicast network was it lack of robustness w.r.t network design; it required specific network design, lacking this the likely outcome was EDAS-dr clients losing their connections to EDAS-ds. The new DS 3 series networking does not require a optimal network design. If the network is poorly designed and it is heavily and/or erratically loaded, the DR clients will get data updates only at a reduced rate that is limited by the available network bandwidth. It is however highly recommended that users do a bandwidth analysis of their network so as to ensure adequate update performance to all DR clients.

1.6.6.4. Detection¶

1.6.6.5. Subscription¶

A key feature to managing bandwidth usage with the TCP connection is the use of subscription to channels. In EDAS-ds ( <= 2.94 ) all channels were sent on the multicast regardless if any client was actually viewing the data. The DS 3 series networking allows individual clients to “subscribe” to channels. Subscribing to a channel in DR simply means make the channel available for plotting. DR also has the intelligence to dynamically tune the subscription to channels based on if the plot is visible, this excludes any plots that require history - only for instantaneous data (i.e. Time or Magnitude Plots). The DS API can read any and all data types continuously or at the users discretion.

1.6.6.6. Plot Update Rates¶

DR performance expectations for a minimal network design with the given DS Configuration:

1.6.6.7. Network Designs¶

The following network diagrams indicate the physical network wiring. Each named rectangle indicates a computer system and each line exiting a system indicates a separate physical NIC. The named bars indicate a separate isolated physical network switch. The network addressing is not shown on these diagrams.