Systems and methods for handling telescopic FQDNs

1. A method performed by a first node implementing a first network function (NF) in a visited network (VPLMN) for communicating with a third node implementing a second NF in a home network (HPLMN), the method comprises:

determining that the third node should be communicated with;

sending towards a second node implementing a Security Edge Protection Proxy (SEPP) in the visited network, a request fora telescopic Fully Qualified Domain Name (FQDN) for the third node in the home network to be used by the first node in the visited network to communicate with the third node in the home network, the request comprises a FQDN of the third node in the home network;

receiving, from the second node, the telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label to be used by the first node to communicate with the third node; and

communicating with the third node in the home network via the second node in the visited network using the received telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label.

2. The method of claim 1 further comprising: communicating with the third node in the home network by sending to the second node in the visited network a service request comprising the received telescopic FQDN for the third node.

3. The method of claim 2 wherein the service request is any one of: a discovery request, Oauth2 Access Token Request or a subscription request.

4. The method of claim 1 , further comprising one or more of the following: the first node implements a visited Network Repository Function (NRF); the second node implements a visited SEPP; and the third node implements a home NRF.

5. The method of claim 1 further comprising: communicating with the third node by sending a service request to another node (SEPP2) using the telescopic FQDN to communicate with the third node.

6. A method performed by a second node implementing a Security Edge Protection Proxy (SEPP) in a visited network (VPLMN) for enabling communication with a third node implementing a second Network Function (NF) in a home network (HPLMN), the method comprises:

receiving, from a first node implementing a first NF in the visited network, a request for a telescopic Fully Qualified Domain Name (FQDN) for the third node in the home network to be used by the first node in the visited network to communicate with the third node in the home network, the request comprises a FQDN of the third node in the home network;

generating the telescopic FQDN;

transmitting, to the first node, the telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label to be used by the first node to communicate with the third node; and

enabling communication with the third node in the home network using the telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label.

7. The method of claim 6 , further comprising one or more of the following: the first node implements a visited Network Repository Function (NRF); the second node implements a visited SEPP; and the third node implements a home NRF.

8. The method of claim 6 further comprising: receiving the service request from the first node, which service request comprises the received telescopic FQDN for communicating on behalf of the first node with the third node using the telescopic FQDN.

9. A first node implementing a first network function (NF) in a visited network (VPLMN) for communicating with a third node implementing a second NF in a home network (HPLMN), the first node comprising:

processing circuitry configured to:

determine that the third node should be communicated with;

send towards a second node implementing a Security Edge Protection Proxy (SEPP) in the visited network, a request for a telescopic Fully Qualified Domain Name (FQDN) for the third node in the home network to be used by the first node in the visited network to communicate with the third node in the home network, the request comprises a FQDN of the third node in the home network;

receive, from the second node, the telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label to be used by the first node to communicate with the third node; and

communicate with the third node in the home network via the second node in the visited network using the received telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label.

10. A second node implementing a Security Edge Protection Proxy (SEPP), in a visited network (VPLMN) for enabling communication with a third node implementing a second Network Function, NF, in a home network (HPLMN), the second node comprising:

processing circuitry configured to:

receive, from a first node implementing a first NF in the visited network, a request for a telescopic Fully Qualified Domain Name, FQDN, for the third node in the home network to be used by the first node in the visited network to communicate with the third node in the home network, which request comprises a FQDN of the third node in the home network;

generate a telescopic FQDN;

transmit, to the first node, the telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label to be used by the first node to communicate with the third node; and

enable communication with the third node in the home network using the telescopic FQDN for the third node wherein the FQDN for the third node in the home network is flattened to a single label.