Architecture Domains

Within an EA Framework one can define various domains for further focus. Examples could be Business, Information, Data, Applications, Storage, Security, Networks, Disaster Recovery, etc. These domains could relate to one of the layers in an EA framework, but they could also span across all layers (e.g. Disaster Recovery concerns the enterprise from a Business level right through to an Infrastructure level).
It seems that not many enterprises have a central department that practises EA on all levels from Business to Infrastructure, e.g. Business Architecture is often executed in some business department removed from the IT department. We would like to hear from anyone where EA is practised centrally on all levels of the organisation.