Method and apparatus for managing transport of delay-sensitive packets

Patent metadata

Field	Value
Publication number	US-11206219-B2
Application number	US-201716762670-A
Country	US
Kind code	B2
Filing date	Nov 13, 2017
Priority date	Nov 13, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

A method of managing transport of packets transmitted over a time division multiplexed, TDM, link in a network. The method performed at a second network node comprises: receiving ( 102 ) blocks of data from a first network node. Data from one packet is received in a plurality of blocks and a first block from a packet has a time-stamp indicating arrival time of the packet at the first network node. The blocks are multiplexed for transmission over the TDM link. The method also comprises: queuing ( 106 ) the received blocks and if a block from the top of the queue ( 108, 110 ) has a time-stamp ( 110 —yes) and a maximum allowed latency has been exceeded ( 112 ) the method discards ( 116 ) blocks containing data from the same packet as the block with said time-stamp if there is at least one block containing data from another packet in the queue ( 114 —yes). An apparatus is also disclosed.

First claim

The invention claimed is:

1. A method of managing transport of packets transmitted over a time division multiplexed, TDM, link in a network, the method performed at a second network node and comprising:
receiving blocks of data from a first network node, wherein data from one packet is received in a plurality of blocks and a first block from a packet has a time-stamp indicating an arrival time of the packet at the first network node, the blocks being multiplexed for transmission over the TDM link;
queuing the received blocks in a queue;
checking a block from a top of the queue;
determining that the checked block has a time-stamp;
using the time-stamp of the checked block to determine if a maximum allowed latency, of a packet for which the checked block contains data, has been exceeded; and
responsive to determining that the maximum allowed latency has been exceeded and that there is at least one block containing data from another packet in the queue, discarding blocks containing data from the same packet as the checked block.

2. The method according to claim 1 , further comprising:
checking another block from a top of the queue;
determining that said another block has a time-stamp;
using the time-stamp of said another block to determine if a maximum allowed latency, of a packet for which said another block contains data, has been exceeded;
responsive to determining that the maximum allowed latency, of the packet for which said another block contains data, has not been exceeded:
assembling the packet for which said another block contains data, using the first and remaining blocks containing data from that packet; and
delivering said assembled packet to a destination egress port of the second network node.

3. The method according to claim 1 , further comprising:
checking another block from a top of the queue;
determining that said another block has a time-stamp;
using the time-stamp of said another block to determine if a maximum allowed latency, of a packet for which said another block contains data, has been exceeded;
responsive to determining that the maximum allowed latency, of the packet for which said another block contains data, has been exceeded and that there is no block containing data from another packet in the queue:
assembling the packet for which said another block contains data, using the first and remaining blocks containing data from that packet; and
delivering said assembled packet to a destination egress port of the second network node.

4. The method according to claim 3 , further comprising:
after starting to assemble the packet for which said another block contains data, finding a new block with a time-stamp in the queue; and
responsive to finding the new block with the time-stamp in the queue, stopping assembly of the packet for which said another block contains data and discarding the blocks from the packet being assembled.

5. The method according to claim 1 , wherein each block comprises a first label identifying a destination egress port at the second network node.

6. The method according to claim 5 , wherein the first label further identifies an ingress port at the first network node.

7. The method according to claim 1 , wherein each block comprises a second label identifying an ingress port at the first network node.

8. The method according to claim 1 , wherein each block comprises a third label identifying a packet from which data is carried in the block.

9. The method according to claim 1 , wherein a last block with data from a packet comprises a fourth label identifying said block as the last block of the packet.

10. The method according to claim 1 , further comprising checking if there is at least one block containing data from another packet in the queue by checking if there is at least one time-stamped block in said queue.

11. The method according to claim 1 , further comprising discarding, without queuing, incoming blocks which do not have a matching time-stamped block in the queue or in an output packet assembler.

12. The method according to claim 1 , wherein a message transmitted from the first network node to the second network node occupies more than one packet, wherein the blocks containing data from the packets of said message comprise a fifth label identifying said message, and wherein the method comprises discarding blocks with the same fifth label responsive to determining that the maximum allowed latency has been exceeded for at least one of the packets of said message.

13. The method according to claim 1 , wherein a packet comprises an eCPRI, evolved-Common Public Radio Interface, message or a plurality of concatenated eCPRI messages.

14. A second network node for managing transport of packets transmitted over a time division multiplexed, TDM, link in a network, the second network node comprising:
a processor and a memory, the memory containing instructions executable by the processor such that the second network node is operative to:
receive blocks of data from a first network node, wherein data from one packet is received in a plurality of blocks and a first block from a packet has a time-stamp indicating an arrival time of the packet at the first network node, the blocks being multiplexed for transmission over the TDM link;
queue the received blocks in a queue;
check a block from a top of the queue;
if the checked block has a time-stamp, determine if a maximum allowed latency has been exceeded using the time-stamp; and
if the maximum allowed latency has been exceeded according to said determining and there is at least one block containing data from another packet in the queue, discard blocks containing data from the same packet as the block with said time-stamp.

15. The second network node according to claim 14 , the memory containing instructions executable by the processor such that the second network node is operative to, if it is determined that the maximum allowed latency has not been exceeded:
assemble a packet using the first and remaining blocks containing data from the packet; and
deliver said assembled packet to a destination egress port of the second network node.

16. The second network node according to claim 14 , the memory containing instructions executable by the processor such that the second network node is operative to, if it is determined that the maximum allowed latency has been exceeded and there is no block containing data from another packet in the queue:
assemble a packet using the first and remaining blocks containing data from the packet; and
deliver said assembled packet to a destination egress port of the second network node.

17. The second network node according to claim 16 , the memory containing instructions executable by the processor such that the second network node is operative to stop the assembling and discard the blocks containing data from the packet if, after starting to assemble the packet, a new block with a time-stamp is found in the queue.

18. The second network node according to claim 14 , the memory containing instructions executable by the processor such that the second network node is operative to check if there is at least one block containing data from another packet in the queue by checking if there is at least one time-stamped block in said queue.

19. The second network node according to claim 14 , wherein a packet comprises an eCPRI, evolved-Common Public Radio Interface, message or a plurality of concatenated eCPRI messages.

20. A network comprising:
a first network node; and

Assignees

• Ericsson Telefon Ab L M

Inventors

• Debenedetti Paolo
• Stracca Stefano

Classifications

• H04L47/283 Primary

  in response to processing delays, e.g. caused by jitter or round trip time [RTT] · CPC title

• H04L2012/5652

  Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly · CPC title

• H04L47/32

  by discarding or delaying data units, e.g. packets or frames · CPC title

• H04L47/36

  by determining packet size, e.g. maximum transfer unit [MTU] · CPC title

• H04L47/564 Primary

  Attaching a deadline to packets, e.g. earliest due date first · CPC title