Congestion control monitoring
In a first aspect, a method of a device configured to monitor congestion for incoming data packets is provided. The method comprises determining whether or not a bit rate of incoming data packets indicated to be sent from a node capable of scalable congestion control exceeds a predetermined bit rate threshold value being lower than a maximum allowable bit rate of outgoing data packets from the device; and if so selectively marking the outgoing data packets as being subjected to congestion, wherein the marking is performed by less frequently marking outgoing data packets having a bit rate closer to the predetermined bit rate threshold value and more frequently marking outgoing data packets having a bit rate closer to the maximum allowable bit rate.
1 . A method of operation by a device configured for operation in a communication network, the method comprising:
transmitting outgoing data packets corresponding to incoming data packets of a packet flow originating from a node that is capable of scalable congestion control;
determining whether or not a bit rate of the incoming data packets exceeds a predetermined bit rate threshold value that is lower than a maximum allowable bit rate applicable to the packet flow; and
responsive to the bit rate of the incoming data packets exceeding the predetermined bit rate threshold value, applying congestion marking to a fraction of the outgoing data packets, and determining the fraction based on an extent to which the bit rate of the incoming data packets exceeds the predetermined bit rate threshold value.
2 . The method of claim 1 , wherein the fraction becomes one-hundred percent upon the bit rate reaching the maximum allowable bit rate.
3 . The method of claim 2 , wherein, for a bit rate range going from the predetermined bit rate threshold value to the maximum allowable bit rate, the fraction increases linearly from zero percent to one-hundred percent.
4 . The method of claim 2 , wherein the fraction is computed based on the difference between the bit rate of the incoming data packets and the predetermined bit rate threshold value.
5 . The method of claim 1 , further comprising determining that the node is capable of scalable congestion control based on an indication included in the incoming data packets.
6 . The method of claim 1 , wherein the scalable congestion control comprises Low Latency Low Loss Scalable Throughput (L4S).
7 . The method of claim 1 , wherein applying the congestion marking comprises, for each outgoing data packet marked, setting an Explicit Congestion Notification (ECN) flag in an outgoing data packet header to “11”.
8 . The method of claim 1 , wherein the device is one of a User Plane Function (UPF) being configured to receive the predetermined bit rate threshold value and the maximum allowable bit rate from a Policy Control Function (PCF), a Gateway General Packet Radio Service Support Node (GGSN) being configured to receive the predetermined bit rate threshold value and the maximum allowable bit rate from a Home Location Register (HLR), and a Packet Data Network Gateway (PGW) being configured to receive the predetermined bit rate threshold value and the maximum allowable bit rate from a Policy and Charging Rules Function (PCRF).
9 . The method of claim 1 , further comprising limiting a bit rate of the outgoing data packets to the maximum allowable bit rate by either discarding or buffering at least some of the incoming data packets.
10 . A non-transitory computer readable medium storing computer program instructions that, when executed by a processor of a device in a communication network, configure the device to:
transmit outgoing data packets corresponding to incoming data packets of a packet flow originating from a node that is capable of scalable congestion control;
determine whether or not a bit rate of the incoming data packets exceeds a predetermined bit rate threshold value that is lower than a maximum allowable bit rate applicable to the packet flow; and
responsive to the bit rate of the incoming data packets exceeding the predetermined bit rate threshold value, apply congestion marking to a fraction of the outgoing data packets, and determine the fraction based on an extent to which the bit rate of the incoming data packets exceeds the predetermined bit rate threshold values.
11 . A device comprising:
a memory storing instructions; and
a processor to execute the instructions, whereby the processor controls the device to:
transmit outgoing data packets corresponding to incoming data packets of a packet flow originating from a node that is capable of scalable congestion control;
determine whether or not a bit rate of the incoming data packets exceeds a predetermined bit rate threshold value that is lower than a maximum allowable bit rate applicable to the packet flow; and
responsive to the bit rate of the incoming data packets exceeding the predetermined bit rate threshold value, apply congestion marking to a fraction of the outgoing data packets, and determine the fraction based on an extent to which the bit rate of the incoming data packets exceeds the predetermined bit rate threshold value.
12 . The device of claim 11 , wherein the fraction becomes one-hundred percent upon the bit rate reaching the maximum allowable bit rate.
13 . The device of claim 11 , wherein the processor further controls the device to determine that the node is capable of scalable congestion control based on an indication included in the incoming data packets.
14 . The device of claim 11 , wherein, for a bit rate range going from the predetermined bit rate threshold value to the maximum allowable bit rate, the fraction increases linearly from zero percent to one-hundred percent.
15 . The device of claim 11 , wherein the fraction is computed based on the difference between the bit rate of the incoming data packets and the predetermined bit rate threshold value.
16 . The device of claim 11 , wherein the scalable congestion control comprises Low Latency Low Loss Scalable Throughput (LAS).
17 . The device of claim 11 , the device applies the congestion marking by setting an Explicit Congestion Notification (ECN) flag in an outgoing data packet header to “11”.
18 . The device of claim 11 , wherein the device is one of a User Plane Function (UPF) being configured to receive the predetermined bit rate threshold value and the maximum allowable bit rate from a Policy Control Function (PCF), a Gateway General Packet Radio Service Support Node (GGSN) being configured to receive the predetermined bit rate threshold value (TM) and the maximum allowable bit rate from a Home Location Register (HLR), and a Packet Data Network Gateway (PGW) being configured to receive the predetermined bit rate threshold value and the maximum allowable bit rate from a Policy and Charging Rules Function (PCRF).
19 . The device of claim 11 , wherein the device is controlled to limit the bit rate of the outgoing data packets to the maximum allowable bit rate by discarding or buffering at least some of the incoming data packets.