Tracking packet sequence numbers
View Patent ↗Methods, traffic receivers, and computer readable storage media for testing network connections are disclosed. A traffic receiver coupled to a network under test may receive a packet. A packet group identification number (PGID and a sequence number (SN) may be extracted from the received packet. Data associated with the PGID may be retrieved from a memory, the data including a next expected sequence number (NESN), a start of run (SOR), a number of in-order packets (NIO) and a number of duplicate packets (NDP). When SN is equal to NESN, NESN and NIO may be incremented. When SN is less than NESN and SN is greater than or equal to SOR, NDP may be incremented. When SN is greater than NESN, SOR may be set to SN, NESN may be set to SN plus one, and NIO maybe incremented. Updated data may be stored in the memory.
1. A method performed by a traffic receiver coupled to a network under test, comprising:
receiving a stream of packets via the network under test, two or more packets from the stream of packets containing a first packet group identification number (PGID); and
for each of the two or more packets containing the first PGID:
extracting a sequence number (SN) from the received packet;
retrieving data associated with the first PGID from memory within or coupled to the traffic receiver, the data including a next expected sequence number (NESN), a start of run (SOR), a number of in-order packets (NIO) and a number of duplicate packets (NDP);
updating the data, updating the data comprising:
comparing SN to NESN to determine if SN is equal to, less than, or greater than NESN,
when SN is equal to NESN, incrementing NESN and incrementing NIO,
when SN is less than NESN, comparing SN to SOR and, when SN is greater than or equal to SOR, incrementing NDP, and
when SN is greater than NESN, setting SOR to SN, setting NESN to SN plus one, and incrementing NIO; and
storing the updated data in the memory.
2. The method of claim 1 , wherein the data associated with the first PGID includes a number of lost packets (NLO), updating the data further comprising:
when SN is greater than NESN, increasing NLO by a value equal to SN minus NESN.
3. The method of claim 2 , wherein the data associated with the first PGID includes a number of reordered packets (NRO) and a number of late packets (NLA), updating the data further comprising:
when SN is less than NESN and SN is less than SOR:
comparing SN to NESN minus a predetermined late threshold (LT),
when SN is greater than or equal to NESN minus LT, incrementing NRO and decrementing NLO, and
when SN is less than NESN minus LT, incrementing NLA and decrementing NLO.
4. The method of claim 3 , wherein the data associated with the first PGID includes LT.
5. A traffic receiver comprising:
memory to store data associated with a plurality of packet groups; and
logic coupled to the memory, the logic configured to:
receive a stream of packets from a network under test, two or more packets from the stream of packets containing a first packet group identification number (PGID) identifying a first packet group from the plurality of packet groups; and
for each packet containing the first PGID:
extract a sequence number (SN) from the received packet;
retrieve data associated with the first packet group from the memory, the data including a next expected sequence number (NESN), a start of run (SOR), a number of in-order packets (NIO) and a number of duplicate packets (NDP);
update the data, updating the data comprising:
comparing SN to NESN,
when SN is equal to NESN, incrementing NESN and incrementing NIO,
when SN is less than NESN, comparing SN to SOR and, when SN is greater than or equal to SOR, incrementing NDP, and
when SN is greater than NESN, setting SOR to SN, setting NESN to SN plus one, and incrementing NIO; and
store the updated data in the memory.
6. The traffic receiver of claim 5 , wherein
the data associated with the first packet group includes a number of lost packets (NLO), and
updating the data further comprising, when SN is greater than NESN:
increasing NLO by a value equal to SN minus NESN.
7. The traffic receiver of claim 6 , wherein
the data associated with the first packet group includes a number of reordered packets (NRO) and a number of late packets (NLA), and
updating the data associated with the first packet group further comprising, when SN is less than NESN and SN is less than SOR:
comparing SN to NESN minus a predetermined late threshold (LT) to determine if SN is greater than or equal to NESN minus LT or less than NESN minus LT,
when SN is greater than or equal to NESN minus LT, incrementing NRO and decrementing NLO, and
when SN is less than NESN minus LT, incrementing NLA and decrementing NLO.
8. The traffic receiver of claim 7 , wherein the data associated with the first packet group includes LT.
9. A computer-readable non-transitory storage medium storing data that, when used to program to one or more programmable devices, causes the one or more programmable devices to be configured as a traffic receiver comprising logic configured to:
receive a stream of packets from a network under test, two or more packets from the stream of packets containing a first packet group identification number (PGID) identifying a first packet group from the plurality of packet groups; and
for each packet containing the first PGID:
extract a sequence number (SN) from the received packet;
retrieve data associated with the first packet group from a memory, the data including a next expected sequence number (NESN), a start of run (SOR), a number of in-order packets (NIO) and a number of duplicate packets (NDP);
update the data, updating the data comprising:
comparing SN to NESN,
when SN is equal to NESN, incrementing NESN and incrementing NIO,
when SN is less than NESN, comparing SN to SOR and, when SN is greater than or equal to SOR, incrementing NDP, and
when SN is greater than NESN, setting SOR to SN, setting NESN to SN plus one, and incrementing NIO; and
store the updated data in the memory.
10. The computer-readable non-transitory storage medium of claim 9 , wherein
the data associated with the first packet group includes a number of lost packets (NLO), and
updating the data further comprising, when SN is greater than NESN:
increasing NLO by a value equal to SN minus NESN.
11. The computer-readable non-transitory storage medium of claim 10 , wherein
the data associated with the first packet group includes a number of reordered packets (NRO) and a number of late packets (NLA), and
updating the data further comprising, when SN is less than NESN and SN is less than SOR:
comparing SN to NESN minus a predetermined late threshold (LT) to determine if SN is greater than or equal to NESN minus LT or less than NESN minus LT,
when SN is greater than or equal to NESN minus LT, incrementing NRO and decrementing NLO, and
when SN is less than NESN minus LT, incrementing NLA and decrementing NLO.
12. The computer-readable non-transitory storage medium of claim 11 , wherein the data associated with the first packet group includes LT.
13. A method performed by a traffic receiver coupled to a network under test, comprising:
receiving a stream of packets via the network under test, each packet a member of a packet group from a plurality of packet groups, each packet containing a packet group identification number (PGID) identifying the respective packet group and a sequence number (SN) defining a relative transmission order within the respective packet group, at least some of the plurality of packet groups including two or more packets; and
for each received packet:
extracting the PGID and the SN from the received packet;
retrieving data associated with the packet group identified by the extracted PGID from memory within or coupled to the traffic receiver, the data including a next expected sequence number (NESN), a start of run (SOR), a number of in-order packets (NIO) and a number of duplicate packets (NDP);
updating the data, updating the data comprising:
comparing SN to NESN to determine if SN is equal to, less than, or greater than NESN,
when SN is equal to NESN, incrementing NESN and incrementing NIO,
when SN is less than NESN, comparing SN to SOR and, when SN is greater than or equal to SOR, incrementing NDP, and
when SN is greater than NESN, setting SOR to SN, setting NESN to SN plus one, and incrementing NIO; and
storing the updated data in the memory.
14. The method of claim 1 , wherein the data associated with the packet group identified by the extracted PGID includes a number of lost packets (NLO), updating the data further comprising:
when SN is greater than NESN, increasing NLO by a value equal to SN minus NESN.
15. The method of claim 2 , wherein the data associated with the packet group identified by the extracted PGID includes a number of reordered packets (NRO) and a number of late packets (NLA), updating the data further comprising:
when SN is less than NESN and SN is less than SOR:
comparing SN to NESN minus a predetermined late threshold (LT),
when SN is greater than or equal to NESN minus LT, incrementing NRO and decrementing NLO, and
when SN is less than NESN minus LT, incrementing NLA and decrementing NLO.
16. The method of claim 3 , wherein the data associated with the packet group identified by the extracted PGID includes LT.