6 Scenarios relating to a level of service of IP connectivity
24.5233GPPArchitecture and functional descriptionCore and enterprise Next Generation Network (NGN) interaction scenariosRelease 17TS
6.1 Scenario 1: IP VPN providing a virtual leased line between NGCN sites
6.1.1 Introduction
This scenario describes the provision of capabilities of the NGN to provide a IP VPN providing a virtual leased line between two NGCN sites. The NGN provides no other functionality.
6.1.2 Involved functional entities – originating
Figure 6.1.1 shows the functional entities involved in the originating scenario in support of IP VPN interconnection.
Figure 6.1.1: Originating scenario for IP VPN interconnection
6.1.3 Involved functional entities – terminating
Figure 6.1.2 shows the functional entities involved in the terminating scenario in support of IP VPN interconnection.
Figure 6.1.2: Terminating scenario for IP VPN interconnection
6.1.4 Interoperability with other scenarios
Subclauses 6.1.2 and 6.1.3 can be combined together to provide an NGN transit scenario.
Subclause 6.1.2 is also intended to interoperate with subclause 6.2.3, and subclause 6.1.3 to interoperate with subclause 6.2.2, in order to allow similar functionality allowing a remote terminal to access an NGCN site.
Interoperability with other business communication scenarios is not possible.
NOTE: Interconnection with other scenarios is not possible, because there is no IP VPN termination in the NGN to support interworking the IP VPN.
6.1.5 Emergency calls
In this scenario, emergency calls have to be supported entirely within the NGCN, and some other scenario provided for delivery to the NGN if required.
6.1.6 Configuration / provisioning issues
The IP level communication between the two NGCNs can be provided using a number of mechanisms. The simplest mechanism is to configure peer IP addresses or FQDNs, and appropriate credentials for the security mechanism in use, in the IP VPN termination. The configuration of this information is outside the scope of the present document.
There are no configuration requirements for supporting this scenario in the NGN.
6.1.7 Security issues
Security is provided by appropriate security mechanism between the IP VPN endpoints, e.g. IPsec or TLS. Whether the NGN provides security mechanisms depends on the service level agreements.
6.1.8 Charging issues
Not applicable.
6.1.9 Transport control issues
The NGCN site interfaces to the NGN using an IP VPN termination and the CNG which can both be an integral part of the NGCN equipment.
NASS can be used, e.g. to support the allocation of a IP address to the CNG, and the authentication of the CNG as an endpoint.
RACS can be used by the NGN to control enforcement of policies within the transport layer. These policies are pushed to the RACS by the NASS each time the CNG attaches to the NGN.
NOTE: The RACS could have similar functionality to the above based on receipt of the policies from the management plane.
6.2 Scenario 2: IP VPN tunnel providing a virtual leased line between a remote terminal and an NGCN sites
6.2.1 Introduction
This scenario describes the provision of capabilities of the NGN to provide a IP VPN tunnel providing a virtual leased line between a remote terminal and an NGCN site. The NGN provides no other functionality.
6.2.2 Involved functional entities – originating
Figure 6.2.1 shows the functional entities involved in the originating scenario in support of IP VPN interconnection.
Figure 6.2.1: Originating scenario for IP VPN interconnection
6.2.3 Involved functional entities – terminating
Figure 6.2.2 shows the functional entities involved in the terminating scenario in support of IP VPN interconnection.
Figure 6.2.2: Terminating scenario for IP VPN interconnection
6.2.4 Interoperability with other scenarios
Subclauses 6.2.2 and 6.2.3 can be used in conjunction with the IP VPN tunnel providing a virtual leased line to an NGCN to provide interoperability. Thus subclause 6.1.2 is also intended to interoperate with subclause 6.2.3, and subclause 6.1.3 to interoperate with subclause 6.2.2.
Interoperability with other business communication scenarios is not possible.
NOTE: Interconnection with other scenarios is not possible, because there is no IPsec IP VPN termination in the NGN to support interworking the IP VPN tunnel.
6.2.5 Emergency calls
In this scenario, emergency calls have to be supported entirely within the NGCN, and some other scenario provided for delivery to the NGN if required.
6.2.6 Configuration / provisioning issues
The IP level communication between the TE CNG and the NGCN can be provided using a number of mechanisms. The simplest mechanism is to configure peer IP addresses or FQDNs, and appropriate credentials for the security mechanism in use, in the IPsec terminations IP VPN termination. The configuration of this information is outside the scope of the present document.
There are no configuration requirements for supporting this scenario in the NGN.
6.2.7 Security issues
Security is provided by appropriate security mechanism between the IP VPN endpoints, e.g. use of IPsec or TLS. The NGN provides no security mechanisms.
6.2.8 Charging issues
Not applicable.
6.2.9 Transport control issues
The TE CND interfaces to the NGN using an IPsec IP VPN termination and the CNG.
NASS can be used, e.g. to support the allocation of a IP address to the CNG, and the authentication of the CNG as an endpoint.
RACS can be used by the NGN to control enforcement of policies within the transport layer. These policies are pushed to the RACS by the NASS at each time the CNG attaches to the NGN.
NOTE: The RACS could have similar functionality to the above based on receipt of the policies from the management plane.
There is no support by functionality in the NASS and RACS.