Optimised packet delivery across a transport network

A method of prioritizing packets for delivery over a transport network interconnecting nodes of a mobile network, where a guaranteed minimum information rate over the transport network is specified for the mobile network, the method comprising:

• for each bearer to be injected into the transport network from the mobile network, specifying a bearer information rate and marking packets up to that rate as conformant with the bearer information rate and marking packets exceeding that rate as non-conformant with the bearer information rate;
• converging a plurality of traffic type streams from the mobile network, each traffic type stream comprising a plurality of bearers;
• maintaining a first token “bucket” in a memory device and filling the bucket with tokens at said minimum information rate;
• maintaining second token buckets in a memory device, for each of the traffic type streams, and filling the second token buckets with tokens overflowing from the first token bucket;
• inspecting packets of the converged traffic type streams to identify packets marked as conformant and non-conformant, and
• for packets of the converged traffic stream types that are marked as conformant, maintaining that marking if there are sufficient tokens in the first and second buckets and deducting an appropriate number of tokens from the bucket(s), and for each packet marked as non-conformant, re-marking the packets as conformant only if there are sufficient tokens in the second bucket associated with the traffic type stream to which the packet belongs,
• wherein said transport network prioritizes the delivery of packets marked as conformant over those packets marked as non-conformant.

An apparatus for interconnecting nodes of a mobile network to a transport network, where a minimum information rate over the transport network is specified for the mobile network, the apparatus comprising:

• a plurality of first interfaces coupled to said mobile network for receiving therefrom respective traffic type flows;
• a second interface coupled to said transport network for sending a converged traffic stream towards said transport network;
• and
• a packet handler for inspecting packets of the incoming traffic type streams to identify packets marked as conformant and non-conformant, and comprising a memory device maintaining a token “bucket” having a fill threshold for each traffic type stream, the packet handler filling the bucket with tokens at said minimum information rate and, for a given packet of a given stream marked as non-conformant, re-marking that packet as conformant if the bucket fill level exceeds the bucket fill threshold defined for the associated traffic type stream;
• wherein said transport network prioritizes the delivery of packets marked as conformant over those packets marked as conformant.

An apparatus for interconnecting nodes of a mobile network to a transport network, where a minimum information rate over the transport network is specified for the mobile network, the apparatus comprising:

• a plurality of first interfaces coupled to said mobile network for receiving therefrom respective traffic type flows;
• a second interface coupled to said transport network for sending a converged traffic stream towards said transport network;
• and
• a packet handler for inspecting packets of the incoming traffic type streams to identify packets marked as conformant and non-conformant, comprising a memory device maintaining a first token “bucket” the packet handler filling the first token bucket with tokens at said minimum information rate and maintaining second token buckets for each of the traffic type streams, the packet handler filling the second token buckets with tokens overflowing from the first token bucket;
• wherein, for packets of the converged traffic stream types that are marked as conformant the packet handler maintains that marking if there are sufficient tokens in the first and second buckets and deducts an appropriate number of tokens from the bucket(s), and for each packet marked as non-conformant, the packet handler re-marks the packets as conformant only if there are sufficient tokens in the second bucket associated with the traffic type stream to which the packet belongs, and
• wherein said transport network prioritizes the delivery of packets marked as conformant over those packets marked as conformant.