Integrated Services Digital Network (ISDN); Signalling System No.7; Support of Virtual Private Network (VPN) Applications with Private Network Q Reference Point Signalling System Number 1 (PSS1) Information Flows; Part 1: Protocol Specification (V1.2.2)
"The present document describes the extensions required for the support of Virtual Private Network (VPN) applications over the public Network Node Interface (NNI). This application makes use of the Application Transport Mechanism (APM) described in EN 301 069-1 for bearer related signalling@ and the Transaction Capability (TC) for signalling involving no bearer. The present document specifies the respective users (i.e. APM-user@ TC-user) to support the PSS1 information flows continuity in VPN applications (Transparent transfer of PSS1 information flows between PINX entities). The public NNI provides transparency to the services of the private network. The private network functionality is defined by ISO in its series of standards for Private Integrated Services Network (PISN). In addition@ the concept of a ""Relay node"" is introduced by the present document. In addition@ this EN describes the interworking between Signalling System Number 7 (ISDN) and extended DSS1 for the support of VPN applications with PSS1 information flows. For the interworking in this EN related to ISUP@ these replace that specified in ETS 300 899 whereas all other interworking of PSS1 information flows is according to that specified in ETS 300 899. The interworking described here provides a sub-set of all possible interworking scenarios and is therefore intended to describe only the relevant mapping of information flows between the two interfaces being described."