Signalling congestion

16) A method of signalling congestion being caused by data items received at a network element in a communications network, the network element having a queue having a length, the method comprising steps of:

• identifying, in respect of each of a plurality of received data items, whether or not said data item is capable of carrying a congestion indication;
• determining, at each of a plurality of different times, respective queue length characterisations, each said queue length characterisation being determined according to a function such as to depend on a current or recent measurement inferring the length of the queue;
• assigning congestion indications to data items identified as being capable of carrying congestion indications with a probability dependent on the most recent of said queue length characterisations;
• and
• applying a sanction in respect of data items identified as not being capable of carrying congestion indications with a probability dependent on probabilities determined in dependence on queue length characterisations determined at a plurality of different times, the probability determined in dependence on the most recent queue length characterisation being more strongly weighted in the assigning of congestion indications to data items identified as being capable of carrying congestion indications than it is in the applying of sanctions in respect of data items identified as not being capable of carrying congestion indications.

17) A method of signalling congestion being caused by items requiring service or capacity from a shared resource, the shared resource having a queue having a length, the method comprising steps of:

• identifying, in respect of each of a plurality of said items, whether or not said item is capable of carrying a congestion indication;
• determining a first queue length characterisation, said first queue length characterisation being determined according to a first function such as to depend on measurements inferring the length of the queue at a plurality of different times;
• determining a second queue length characterisation, said second queue length characterisation being determined according to a second function such as to depend on a current or recent measurement inferring the length of the queue, the most recent queue length being more strongly weighted in said second function than it is in said first function;
• applying a sanction in respect of items identified as not being capable of carrying congestion indications in dependence on said first queue length characterisation;
• and
• assigning congestion indications to items identified as being capable of carrying congestion indications in dependence on said second queue length characterisation.