The next hop redirection explicitly or implicitly changes the next hop for the traffic flow within the same service ID (routing context) or a different service ID (routing context).
If the next hop is not explicitly provided, the next hop is selected automatically, according to the routing lookup in the referenced service ID.
The generic Gx directive:
Charging-Rule-Install <AVP Header: 1001>
Charging-Rule-Definition <AVP Header: 1003>
Charging-Rule-Name <AVP Header: 1005>
Alc-Next-Hop :: <AVP Header: 1023>
Alc-Next-Hop-IP <AVP Header: 1024>
Alc-V4-Next-Hop-Service-id <AVP Header: 1025>
Alc-V6-Next-Hop-Service-id <AVP Header: 1026>
This action overwrites the routing table lookup based on the destination IP and sets the next hop to the:
IPv4/6 address within the same service ID
IPv4/6 address within a different service ID
The next hop search is indirect, which means that if the explicitly provided next hop in the PCC rule cannot be found in the routing table, then an additional routing table lookup is performed to find the path (next hop) to the indirect next hop from the PCC rule.
If only the service-id is specified in PCC rule (without the next hop), then the next hop is selected from the specified service-id based on the destination IP address of the packet.