TopNet implementation: SpW IP Tunnel and Protocol Analyser

Transcription

1 TopNet implementation: SpW IP Tunnel and Protocol Analyser Vitulli R. TEC-EDP Slide : 1

2 SpaceWire System Node 71 Node 72 Node 61 Router 2 Node 73 Node 62 Router 1 Router 3 Node 74 Node 63 Node 75 SpaceWire Sub-System 1 SpaceWire Sub-System 2 Slide : 2

3 Spacewire Tunnel Concept Node 61 PC running SpaceWire IP Tunnel software Node 62 Router 1 Node 63 SpaceWire Sub-System 2 SpaceWire Sub-System 1 Internet Node 71 Node 72 Router 2 Node 73 Key SpaceWire Any TCP/IP network PC running SpaceWire IP Tunnel software Router 3 Node 75 Node 74 Slide : 3

4 Aims of IP Tunnel To provide support for remote, decentralised integration of SpW-based, satellite onboard data-handling sub-systems using the internet to connect the geographically separated sub-systems. To provide a means for monitoring the traffic flowing through the SpaceWire IP Tunnel. To provide a way of monitoring SpaceWire traffic remotely using available multi-port SpaceWire to PC interface units. To enable higher level protocols running over SpaceWire, through a SpaceWire IP Tunnel or through a multi-port SpaceWire interface, to be analysed and displayed. Due to bandwidth limitations and latency of the connection, real-time communication is not possible. Slide : 4

5 Spacewire IP Tunnel Model Host PC Graphical U ser Interface Display Control SpW Driver Java Native Interface Time-Codes SpW Packets IP Tunnel Software TC P /IP S tream s Secure TCP/IP Socket Time- Codes SpW Packets IP grams Interface Driver TCP/IP Driver Interface Unit Ethernet or Other Internet Interface Unit Internet Slide : 5

6 Protocol Analyzer Model Rem ote PC Graphical Use r In te rfa ce Display Remote PC Running Remote Desktop Softw are Control In te rn e t Host PC Graphical User Interface Display Host PC Graphical User Interface Control Protocol Analyser Plug In (e.g. TC P/IP ) Control Display Cargo Protocol Analyser Software Time- Codes SpW P a cke ts Inte rfa ce Driver Inte rfa ce Unit Slide : 6

7 Time-Code and N-Char Sequencing Inside SpaceWire CODEC Time-codes have priority they jump the transmit and receive queues Not possible to ensure full synchronisation of timecodes and data without modifying the SpaceWire CODEC IP Tunnels must preserve N-Char / Time-code ordering The best way is to use a modified SpaceWire-USB Brick, in order to keep time-code to N-Char ordering Slide : 7

8 Link Start/Disconnect IP Tunnels must be completely transparent Tunnel devices shall support notification of link start and link disconnect to the other end of the Tunnel Also link start/disconnect notification has been implemented in the modified SpaceWire-USB Brick Slide : 8

9 Tunnel in a network using routers with timeouts the gap between packet chunks could be greater than the timeouts at the router A proper buffer is necessary at the tunnel exit Buffer contents: Buffer contents: Send chunk above limit Buffer contents: Buffer contents: No EOP No EOP Send one byte TC TC Half buffer length TC TC Slide : 9

10 Operation of Tunnel behind firewall IP Tunnel is using port 80 as a default. One of the 2 Tunnel should be outside the firewall. Alternative solutions: Use of SSH port 22 to forward traffic to a non-privileged port (> 1024) to have a centralised server which provides connection between pairs of Tunnel clients S F C F F C C = Client, F = Firewall, S = Server Slide : 10

11 Tunnel Hardware In order to provide the full functionality, a modified device is required. The IP Tunnel software can also be used with existing SpaceWire devices, such as the SpaceWire-USB Brick. When used with these devices the Tunnel has some limitations (order of time-codes and links disconnect/start) Slide : 11

12 Tunnel Software Changes were required to the driver which provides the interface with the device. The SpaceWire IP Tunnel application provides the man-machine interface and the tunnelling functionality (coded in Java). Windows and Linux drivers are currently available for the SpaceWire devices. Slide : 12

13 Present Status The SpaceWire driver is completed. Detailed testing of the driver was performed, and identified bugs were fixed The Java interface to the driver is completed Tunnel Software is completed and under testing To be done: Complete Protocol Analyzer user interface Complete the User Manuals for both the Tunnel and Protocol Analyzer Delivery date: end of July Slide : 13

14 Follow-on activities Involvement of different actors (industry, university, agency) in a pilot activity for decentralized integration of SpW-based data handling sub-systems that are geographically separated Slide : 14