The purpose of the present document is to give an implementation guide to the relevant Common IMS specifications and functions used in the interconnection of a Next Generation Corporate Network site (NGCN site) to the NGN.

The present document addresses control plane signalling (usage of SIP and SDP protocols, required SIP headers) as well as other interconnecting aspects like security, numbering/naming/addressing and user plane issues such as transport protocol, media and codecs actually covered in a widespread set of 3GPP and ETSI specifications, as seen from the perspective of an NGCN site.

Advice-of-charge aspects are addressed as far as SIP signalling is concerned.

The structure of the present document reflects the historical structure of previous versions of it. All references to ETSI TR 124 969 [i.97] are intended to be to the entire contents of the referenced document, which now forms the contents of the present document, and not to any part which might be implied by any headings within the present document.