Usecase Diagnostics Over The Air

PduApi can be used for diagnosis from a local PC to a remote vehicle.

Neither the local PC nor the vehicle can connect to each other. For that, a server with fixed IP address located on the internet is required.

Both, the local PC and the vehicle can connect to that server. This server establishes the connection between multiple vehicles and multiple local PCs. So such a server is called switch further on.

Inside the PduApi every VCI in a vehicle is represented by one or multiple D-PDU API Modules.

Limitations:

PduApi is scalable as far as it is possible by D-PDU API and/or Linux.

1. The data type for a Module in D-PDU API is UNUM32 : 4.294.967.295
2. From the point of view of the userspace, the socket data type is int (int32_t) which is limited at 2.147.483.647.
   Every connection needs 2 sockets: so a maximum of 1.073.741.823 vehicles can be connected by the Switch/Server.
3. By default linux kernel can hold ~500.000 socket connections:

   ulimit -Ha
   ...
   open files                      (-n) 524288
   ...

   That leads to a maximum of around 250.000 vehicle connections.

Future:

If more vehicles are needed to be managed, a load balancer can be used. This loadbalancer manages multiple virtual Servers.
The Client/PC starts with a filter in PDUConstruct to reduce the maximum of reachable vehicles.

That means there is no more limit to the UNUM32 hMod datatype and an infinite number of VCIs can be accessed without any performance issues on client side.