Highly available data-processing network functions for radio-based networks

1. A system, comprising:

an elastic network interface that receives all inbound network traffic from an external network destined for a radio-based network, including inbound network traffic directed to a plurality of ranges of network addresses;

a plurality of tunnel hosts, individual tunnel hosts being configured to consistently route network traffic corresponding to a respective range of the plurality of ranges of network addresses to a respective user plane function (UPF) of a plurality of UPFs that process the network traffic before forwarding the network traffic to a plurality of user devices on the radio-based network; and

a plurality of route reflectors, individual route reflectors of the plurality of route reflectors receiving routing information from the plurality of UPFs and forwarding the routing information to the plurality of tunnel hosts, the routing information comprising border gateway protocol (BGP) advertisements obtained through respective BGP peering sessions between the individual route reflectors and the plurality of UPFs.

2. The system of claim 1 , wherein the routing information includes a backup route corresponding to a backup UPF of the plurality of UPFs, the backup route corresponding to a particular range of the plurality of ranges of network addresses that is normally routed to another UPF of the plurality of UPFs.

3. The system of claim 2 , wherein the backup UPF is at a first edge location, and the other UPF is at a second edge location.

4. The system of claim 2 , wherein the backup UPF is at a regional data center location, and the other UPF is at an edge location.

5. The system of claim 1 , further comprising a route advertiser, wherein when executed the route advertiser further causes at least one computing device to at least:

advertise a route to the plurality of ranges of network addresses to the external network, the route being to the elastic network interface.

6. The system of claim 1 , further comprising a control plane for the radio-based network that is cellularized into a plurality of control plane cells that operate independently.

7. A system, comprising:

at least one computing device;

an elastic network interface that receives all inbound network traffic from an external network destined for a radio-based network, including inbound network traffic directed to a first range of network addresses and a second range of network addresses;

a tunnel host executable in the at least one computing device, wherein when executed the tunnel host causes the at least one computing device to at least:

receive network traffic from the external network directed at the first range of network addresses corresponding to a plurality of user devices on the radio-based network via the elastic network interface;

determine a first instance of a plurality of instances of a data-processing network function, the first instance handling the first range of network addresses; and

forward the network traffic to the first instance; and

a route reflector that receives receiving routing information from the plurality of instances of the data-processing network function and forwards the routing information to the tunnel host, the routing information comprising border gateway protocol (BGP) advertisements obtained through respective BGP peering sessions between the route reflector and the plurality of instances of the data-processing network function.

8. The system of claim 7 , further comprising another tunnel host, wherein when executed the other tunnel host further causes the at least one computing device to at least:

receive other network traffic from the external network directed at the second range of network addresses corresponding to another plurality of user devices on the radio-based network via the elastic network interface;

determine a second instance of the plurality of instances of the data-processing network function, the second instance handling the second range of network addresses; and

forward the other network traffic to the second instance.

9. The system of claim 7 , further comprising a tunnel control plane, wherein when executed the tunnel control plane further causes the at least one computing device to at least:

launch the tunnel host and another tunnel host in a cloud computing resource;

assign the first range of network addresses to the tunnel host; and

assign the second range of network addresses to the other tunnel host.

10. The system of claim 7 , wherein when executed the route reflector further causes the at least one computing device to at least:

advertise a route for the first range of network addresses to the tunnel host; and

advertise a backup route for the first range of network addresses to the tunnel host.

11. The system of claim 7 , wherein when executed the tunnel host further causes the at least one computing device to at least:

receive outbound network traffic from the first instance; and

forward the outbound network traffic to the external network.

12. The system of claim 7 , wherein when executed the tunnel host further causes the at least one computing device to at least:

determine that a second instance of the plurality of instances of the data-processing network function handles at least a portion of the first range of network addresses after a configuration change;

forward the network traffic to the second instance instead of the first instance;

obtain state information regarding the network traffic from the first instance; and

provide the state information to the second instance.

13. The system of claim 7 , wherein the tunnel host is operated by a cloud service provider, the first instance is on a private network operated by a customer of the cloud service provider, and the customer operates the radio-based network.

14. The system of claim 7 , wherein the data-processing network function is a user plane function (UPF) to process the network traffic before sending the network traffic to the plurality of user devices.

15. A method, comprising:

consistently routing, by a tunnel host executed in at least one computing device, network traffic associated with a range of network addresses in a radio-based network to a first instance of a data-processing network function instead of a second instance of the data-processing network function;

detecting a problem with the first instance of the data-processing network function;

redirecting, by the tunnel host, additional network traffic associated with the range of network addresses from the first instance of the data-processing network function to the second instance of the data-processing network function;

receiving, by at least one route reflector executed in the at least one computing device, routing information indicating that the second instance of the data-processing network function handles the range of network addresses from the second instance of the data-processing network function, wherein the routing information comprises border gateway protocol (BGP) advertisements obtained through a BGP peering session between the at least one route reflector and the second instance of the data-processing network function; and

sending, by the at least one route reflector, the routing information to the tunnel host.

16. The method of claim 15 , further comprising consistently routing, by another tunnel host executed in the at least one computing device, other network traffic associated with a different range of network addresses in the radio-based network to the second instance of the data-processing network function instead of the first instance of the data-processing network function.

17. The method of claim 15 , further comprising advertising, by the at least one route reflector, a default route to reach an external network via the tunnel host.

18. The method of claim 15 , wherein the routing information is sent by the at least one route reflector to the tunnel host in response to a poll from the tunnel host.

19. The system of claim 7 , wherein the routing information includes a backup route corresponding to a second instance of the plurality of instances of the data-processing network function, the backup route corresponding to the first range of network addresses that is normally routed to the first instance.

20. The method of claim 15 , wherein the routing information indicates a backup route to a third instance of the data-processing network function for the range of network addresses.