Introduction

29.4153GPPCore network Nb interface user plane protocolsRelease 17TS

The present document specifies the user plane protocol used between two Media Gateways in the CS core network. Through out the present document this protocol shall be referred to as the Nb UP protocol. The Nb UP protocol is for a large part identical to the Iu UP protocol (see 3GPP TS 25.415 [2]), and only the differences between the two protocols are specified. This specification defines the applicability of the UP, as defined in 3GPP TS 25.415 [2], for the Nb interface only.

Given that the Nb UP uses the same PDU types as the Iu UP, the term IuFP is used to refer to the common framing.

For the purpose of the present document, any occurrence of the term "Iu UP" in the corresponding sections of 3GPP TS 25.415 [2], shall be interpreted as "Nb UP".