Jagdip Grewal, Chief Technical Architect, NHS Connecting for Health, presented at the OASIS Open Standards forum in London.  Connecting for Health is a large scale deployment of ebXML Messaging.  Electronic Transmission of Prescriptions are a five hundred messages per second. This may go up to seven hundred, the audience was told.

http://events.oasis-open.org/home/sites/events.oasis-open.org.home/files/Jagdip.v2.ppt