I have got a design question. After reading this book -- which was good -- can someone suggest an architectural approach to monitoring and handling errors in the following scenario...

Remote system A process data and FTP's data to local system B, outside the firewall,
Local system B transfers data over the firewall to internal system C,
Internal system C needs to host all error and monitoring information.

Question:
How can I setup a architecture in which systems A and B both pass their monitoring and error information to system C so that the whole process can be monitored from system C? (Monitoring system C will be easy since that is where all monitoring and error handling should converge).

I am think web services but can I stream the data across from systems A and B?

Any thought would be helpful....
Cheers!