Define public gateway migration protocol

[gnarea]

Executive summary

When a user changes the public gateway to which their private gateway is connected, incoming parcels to the private gateway will get lost because they'll continue to be sent to the old public gateway.

The problem you're trying to solve

Service providers can limit this disruption by incorporating this change in their protocol, but this isn't because services shouldn't be concerned with this and there will still be a period of disruption until the endpoint peers update their config.

The solution you'd like

The old public gateway should be notified about the migration; either by the private gateway or the new public gateway. Once this notification is received, the old public gateway should:

• Refuse PDC parcels bound for the private gateway, and provide the PDC client with the address of the new gateway.
• Refuse GSC/CRC requests from the private gateway or on its behalf.
• Deliver all the queued parcels bound for the private gateway to the new public gateway. Redelivery may be attempted. All undelivered parcels should then be deleted.

After N days, the old public gateway should delete all the information it held about the private gateway, including the migration information.

If the private gateway registers with the old public gateway later, the latter should delete the migration information.

Any alternatives you've considered?

No