Flow control in a virtualized communication network

A method of determining oversubscription of a first virtualized network function for enabling flow control in the virtualization of at least one node in a communication network, where the first virtualized network function has packet handling resources comprising at least one queue and being a downstream network function located downstream from at least one second upstream network function in a packet flow between the network functions, the method being performed by flow control functionality in a device for determining oversubscription and comprising:

• monitoring said at least one queue;
• determining if the first virtualized network function is oversubscribed based on said monitoring;
• and
• generating, in case the first virtualized network function is determined to be oversubscribed, an instruction (RCI) for at least one upstream network function to change its transmission rate to the first virtualized network function in order to reduce the oversubscription.

A computer program product for determining oversubscription of a first virtualized network function in order to enable flow control in the virtualizing of at least one node in a communication network, where the first virtualized network function has packet handling resources comprising at least one queue and is a downstream network function located downstream from at least one second upstream network function in a packet flow between the network functions, the computer program product comprising a non-transitory computer readable medium storing a computer program comprising code which, when executed on at least one processor, cause the at least one processor to:

• monitor said at least one queue;
• determine if the first virtualized network function is oversubscribed based on said monitoring;
• and
• instruct, in case oversubscription is being determined, at least one virtualized upstream network function to change its transmission rate to the first virtualized network function in order to reduce the oversubscription.