Service provision in scenarios with network address translation

A method for operating a policy control entity configured to control policy rules for a data packet session of a user in a cellular network, the method comprising:

• receiving a policy request from a session control entity requesting at least one policy rule for the data packet session;
• determining the at least one policy rule for the data packet session, the determining comprising determining that the policy control entity be informed about an address translation carried out in a user plane on the data packets of the data packet session;
• and
• transmitting a policy response to the session control entity, the policy response comprising the at least one policy rule which comprises a request to provide information about the address translation carried out in the user plane on the data packets of the data packet session.

A method for operating a user plane entity configured to handle a user plane of a data packet session of a user in a cellular network, the method comprising:

• receiving rules for handling the data packet session from a session control entity, the rules comprising a translation detection rule by which the user plane entity is requested to inform the session control entity about the address translation that has taken place in the user plane;
• storing the received rules with the translation detection rule;
• receiving data packets of a new data packet session;
• determining that the received rules apply to the new data packet session, and that an address translation has to be carried out in the data packets of the new data packet session;
• translating at least one network address in the data packets of the new data packet session in which a first network address of the data packets is replaced by a second network address of the data packets different from the first network address;
• and
• transmitting a session report to the session control entity, the session report comprising binding information with the first network address of the data packets before the address translation and the second network address different from the first network address after the address translation.

A session control entity configured to control a data packet session of a user in a cellular network, the session control entity comprising a memory and at least one processing unit, the memory containing instructions executable by the at least one processing unit to configure the session control entity to:

• transmit a policy request to a policy control entity of the cellular network, requesting at least one policy rule for the data packet session;
• receive a policy response from the policy control entity including the at least one policy rule for the data packet session, the policy response further comprising a request to provide information about an address translation carried out in a user plane on the data packets of the data packet session;
• and
• transmit rules for handling the data packet session to a user plane entity configured to handle the user plane of the data packet session, the rules comprising a translation detection rule by which the user plane entity is requested to inform the session control entity about the address translation that has taken place in the user plane.

A policy control entity configured to control policy rules for a data packet session of a user in a cellular network, the policy control entity comprising a memory and at least one processing unit, the memory containing instructions executable by the at least one processing unit to configure the policy control entity to:

• receive a policy request from a session control entity requesting at least one policy rule for the data packet session;
• determine the at least one policy rule for the data packet session, the determining comprising determining that the policy control entity be informed about an address translation carried out in a user plane on the data packets of the data packet session;
• and
• transmit a policy response to the session control entity, the policy response comprising the at least one policy rule which comprises a request to provide information about the address translation carried out in the user plane on the data packets of the data packet session.

A user plane entity configured to handle a user plane of a data packet session of a user in a cellular network, the user plane entity comprising a memory and at least one processing unit, the memory containing instructions executable by the at least one processing unit to configured the user control entity to:

• receive rules for handling the data packet session from a session control entity, the rules comprising a translation detection rule by which the user plane entity is requested to inform the session control entity about the address translation that has taken place in the user plane;
• store the received rules with the translation detection rule;
• receive data packets of a new data packet session;
• determine that the received rules apply to the new data packet session, and that an address translation has to be carried out in the data packets of the new data packet session;
• translate at least one network address in the data packets of the new data packet session in which a first network address of the data packets is replaced by a second network address of the data packets different from the first network address;
• and
• transmit a session report to the session control entity, the session report comprising binding information with the first network address of the data packets before the address translation and the second network address different from the first network address after the address translation.