Flow State Aware QoS Management Without User Signalling

A system utilizing a packet network node comprising:

• an input for receiving one or more packets;
• means for detecting congestion in said packet network node relating to any flow or group of flows and associated limits of network capacity assigned to such a flow or group of flows;
• means for detecting excessive packet bursts or jitter in said packet network node relating to any flow or group of flows and associated limits of burstiness or jitter assigned to such a flow or group of flows;
• a communication identifier store for storing a set of communication identifiers;
• means for detecting communication announcement packets received at said input, and responsive to said detection to store within said communication identifier store, a communication identifier included in said communication announcement packet;
• means for detecting new flows that have commenced without a communication announcement packet received at said input, and responsive to said detection to store within said communication identifier store, a communication identifier;
• means for removing, on a predetermined condition being met, a “vulnerable to discard” status associated with a communication identifier from said communication identifier store prior to the cessation of the communication;
• means for delaying said arriving packets;
• means for identifying either a delayed packet or latest received packet that should be discarded when burstiness or jitter detection means determine that such a deletion is required on any flow or group of flows;
• means that will automatically select for discard of a packet of a flow that is vulnerable to discard or, if none, then any packet that has lowest preference priority within the delayed or latest arriving set of packets associated with the said flow or group of flows;
• means for, upon the detection of congestion caused by any flow or group of flows as determined by said congestion detection means, identifying packets received at said input belonging to a communication associated with one of said communication identifiers stored in said communication identifier store;
• and forward packets such that packets without the “vulnerable to discard” status within said group of flows associated with the said congestion are forwarded in preference to packets belonging to flows of the same group that contain the “vulnerable to discard” status;
• means for classifying a new flow that has commenced without a communication announcement packet, comprising:
• means for determining any policy associated with the new flow, based upon header information carried in the packet at any layer of encapsulation, or information associated the physical link on which the packet arrived;
• means for assigning both an initial minimum guaranteed rate and an additional rate whose value is not guaranteed to be sustained but allows the use of additional spare capacity;
• means for frequently reviewing the amount of additional spare capacity that can be assigned to any said flow that has commenced without a communication announcement packet, and means to assign and police any revised additional spare capacity plus minimum guaranteed capacity against the rate of forwarding of bytes along said flow;
• means for measuring the forwarding rates of any flow including means to commence such a measurement for a fixed interval when and if required, as determined through said policy information;
• and
• means to update for any flow or group of flows the assigned rate limits or preference priorities or vulnerability to discard based on the result of one or more measurements of the forwarding rate of any said flow or group of flows, including means to revise the policed rate(s) of the flow or group of flows based on both current minimum guaranteed rate(s) and current additional available rate(s), where either of these components of assigned capacity may be zero.

A packet network node including a packet communications source comprising:

• means for generating one or more communication announcement packets, comprising:
• means for determining any policy information that can be derived for a new flow that has commenced without a communication announcement packet;
• and
• means for including flow identifier information in the header of said generated communication announcement packet which is the same flow identifier that is found in the arriving packet of a new flow that had started without a communication announcement packet;
• means arranged in operation to send said generated communication announcement packets along any output link, either being the same output link that will be chosen for the other packets of the corresponding flow, or any other link depending on policy information.