Re-routing of diameter commands

A diameter routing unit configured to route diameter commands of a data packet session using a diameter protocol in a mobile communications network, the diameter routing unit comprising:

• a storage circuit configured to store information about which policy and charging control unit is handling which data packet session and to store information about a presence of an additional diameter routing unit which routes diameter commands of the diameter protocol to the same pool of policy and charging control units as the diameter routing unit;
• an input/output circuit configured to receive a diameter command for a data packet session;
• a control circuit configured to check whether information is present in the storage circuit about which policy and charging control unit is handling the session to which the received diameter command belongs;
• wherein the control circuit is configured to:
• determine whether to forward the received diameter command to a policy and charging control unit handling the packet data session or to the additional diameter routing unit based respectively on whether or not information about which policy and charging control unit is handling the data packet session is present in the storage unit;
• forward the received diameter command according to the determination.

A method, performed by a system comprising a diameter routing unit and an additional diameter routing unit, to route diameter commands of a data packet session using a diameter protocol in a mobile communications network, each of the diameter routing units comprising a storage unit storing information which policy and charging control unit is handling which data packet session and the storage unit of the diameter routing unit storing information about a presence of the other diameter routing unit, the diameter routing units routing diameter commands to the same pool of policy and charging control units, the method comprising:

• receiving, at the diameter routing unit, a diameter command for a data packet session;
• determining, by the diameter routing unit, whether to forward the received diameter command to a policy and charging control unit handling the packet data session or to the additional diameter routing unit based respectively on whether or not information about which policy and charging control unit is handling the data packet session is present in the storage unit of the diameter routing unit;
• forwarding, by the diameter routing unit, the received diameter command according to the determination;
• checking, at the additional diameter routing unit if the received diameter command is forwarded to additional diameter routing unit, whether information is present in the storage unit of the additional diameter routing unit about which policy and charging control unit is handling the session to which the received diameter command belongs, and if so, the additional diameter routing unit:
• identifying the policy and charging unit handling the session;
• and
• forwarding the received diameter command to the identified policy and charging control unit in accordance with the stored information.

A system comprising:

• a diameter routing unit and an additional routing unit, each of the diameter routing units configured to route diameter commands of a data packet session using a diameter protocol to the same pool of policy and charging control units in a mobile communications network, each of the diameter routing units comprising a storage unit storing information about which policy and charging control unit is handling which data packet session and the storage unit of the diameter routing unit storing information about a presence of the additional diameter routing unit;
• wherein the diameter routing unit comprises:
• an input/output circuit configured to receive a diameter command for a data packet session,
• a control circuit configured to:
• determine whether to forward the received diameter command to a policy and charging control unit handling the packet data session or to the additional diameter routing unit based respectively on whether or not information about which policy and charging control unit is handling the data packet session is present in the storage unit of the diameter routing unit;
• forward the received diameter command according to the determination;
• wherein the additional diameter routing unit comprises:
• an input/output circuit configured to receive the forwarded diameter command;
• a control circuit configured to check whether information is present in its storage unit about which policy and charging control unit is handling the session to which the forwarded diameter command belongs, and if so:
• identify the policy and charging control unit which is handling the session;
• and
• forward the forwarded diameter command to the identified policy and charging control unit in accordance with the stored information.