6.1 Overview

ADN-AE, ASN/MN-CSE and the serving CSE (SCS) communicate after completion of the underlying 3GPP network bearer establishment and discovery of the serving CSE (SCS). Data can then traverse between the oneM2M entities over the IP connection in the underlying 3GPP network over the 3GPP Gi/SGi interface. Figure 6.1-1 depicts the connectivity between the ADN-AE, ASN/MN-CSE and the CSE (SCS).

Figure 6.1-1: Connectivity Establishment between ASN/MN-CSE or ADN-AE and CSE (SCS)

For ADN/ASN/MN initiated connectivity establishment, it is assumed that there is no connectivity previously established, i.e. no association between the ASN/MN-CSE or ADN-AE and the serving CSE (SCS) exists. When the ASN/MN-CSE or ADN-AE needs to send data to the serving CSE (SCS) it first discovers the serving CSE (SCS), which is located in a packet data network, and establishes a connection. Two methods can be used, as follows:

1. Use of DHCP and DNS.
2. Pre-configuration.

For serving CSE (SCS) initiated connectivity establishment, it is assumed that there is no connectivity previously established between the ASN/MN-CSE or ADN-AE and the serving CSE (SCS). When the serving CSE (SCS) needs to contact the ASN/MN-CSE to send data or request data, connectivity between them is established. This connectivity is triggered by the serving CSE (SCS).

The ASN/MN-CSE or ADN-AE requests the DNS server address from the DHCP server followed by requesting the serving CSE IP address from the DNS server.