Method and apparatus to determine whether a network is quality of service enabled

• US 7,397,801 B2
• Filed: 04/08/2005
• Issued: 07/08/2008
• Est. Priority Date: 04/08/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Zuberi, Khawar M., Jourdain, Mathias
• Primary Examiner(s): Yao; Kwang Bin
• Assistant Examiner(s): Elpenord; Candal
• Application Number:
  US11/101,962
• Publication Number:
  US 20060227713A1
• Time in Patent Office: 1,187 Days
• Field of Search: 370/241, 370229-230, 370/395.41, 370/395.42, 370/395.43, 370/248, 370/236, 370/395.21
• US Class Current: 370/395.21
• CPC Class Codes: H04L 1/242 by comparing a transmitted test signal with a locally generated replica
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 43/55 Testing of service level quality, e.g. simulating service usage
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/115 using a dedicated packet
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 47/35 by embedding flow control information in regular packets, e.g. piggybacking

Abstract

A method and apparatus to determine whether a network is quality of service enabled is disclosed. The method may send a variety of test packets through a network and depending on how the network handles the packets, a determination may be made whether the network does not support packets with quality of service identification, tolerates packets with quality of service identification or supports packets with quality of service identification.

Claims

1. A method of determining whether a network path is quality of service (QoS) enabled comprising:

on a sink side, when receiving traffic from an unknown source sending noise to the source using a socket comprising;

sending n large packets back to back where n is at least 1;

and on a source side sending test probes to the sink comprising;

sending a large high priority probe packet with an oversized flag;

waiting for notification that the large high priority packet has entered the network;

sending y normal priority packets where y is greater than or equal to 1;

waiting for notification that these normal priority packets have entered the network;

sending at least one high priority probe packet;

waiting for notification that the high priority packet has entered the network;

reviewing the packets sent and received and if no large packet was received after a plurality of sends, determining that the network fabric does not support QoS;

reviewing the packets sent and received and if all packets were received in the order sent, determining that the path tolerates QoS enabled traffic; and

reviewing the packets sent and received and if all the sent packets were received and a later sent higher priority packet was received prior to a lower priority earlier sent packet, determining that QoS is supported.

2. The method of claim 1, further comprising when enough packets are received to ascertain the QoS properties of the path, stop the method.

3. The method of claim 1, further comprising comparing the order of packets received to the order the packets were sent.

4. The method of claim 1, further comprising sending all packets as close to one another as possible.

5. The method of claim 1, wherein a large probe is the largest possible size possible according to the fabric used before any priority indications are added.

6. The method of claim 1, wherein incoming probe packets from the same source comprise a sequence number of a new packet that is that incrementally larger than the previously received packet and the incoming packet sequence number is used to compare to the sent packet sequence number to determine if the sequence of the sent packets changed during transit.

7. A method of determining whether a network path is quality of service (QoS) enabled comprising:

on a sink side, when receiving traffic from an unknown source;

storing an Internet Protocal (“

IP”

) address and source port of the source;

creating a user datagram protocal (“

UDP”

) socket;

connecting this socket to the source IP address and source port received; and

sending noise to the source using this socket comprising;

sending n large packets back to back where n is greater than 1;

repeating the send; and

validating the order of packets received from each source;

and on a source side;

connecting a first datagram socket and a second datagram socket to the same remote port of the sink;

tagging the traffic on the first or the second socket with higher priority values than those used by the noise sent by the sink; and

sending test probes to the sink comprising;

sending a large high priority probe packet using a mechanism by which it is possible to track which packet was oversized;

waiting for notification that the large high priority packet has entered the network;

sending y best-effort priority large probe packets using the second socket where y is greater than or equal to 1;

sending one best-effort priority small probe packets using the second socket;

waiting for notification that all these sends have entered the network;

sending a small high priority probe packet on the first socket; and

waiting for notification that the send of the small high priority packet has entered the network;

reviewing the packets sent and received and if no large packet was received and some later sent lesser priority packets have been received after a plurality of sends, determining that the network fabric does not support QoS;

reviewing the packets sent and received and if all packets were received in the order sent, determining that the path tolerates QoS enabled traffic; and

reviewing the packets sent and received and if all the sent packets were received and a later sent higher priority packet was received prior to a lower priority earlier sent packet, determining that QoS is supported.

8. The method of claim 7, further comprising when enough packets are received to ascertain the QoS properties of the path, stop the method.

9. The method of claim 7, further comprising comparing the order of packets received to the order the packets were sent.

10. The method of claim 7, further comprising sending all packets as close to one another as possible.

11. The method of claim 7, wherein a large probe is the largest possible size possible according to the fabric used before any priority indications are added.

12. The method of claim 7, wherein a probe packet comprises:

an oversized field when selected indicates that the packet is oversized for the fabric used;

a train size field that indicates the number of packets that are part of this train; and

a sequence number that is incrementally larger than the previously sent packet.

13. The method of claim 7, wherein incoming probe packets from the same source comprise a sequence number of a new packet that is that incrementally larger than the previously received packet.

14. The method of claim 7, wherein a first incoming probe packets from the same source is at least 1500 bytes before a 802.1p tag is applied which will make the packet 1504 bytes and the oversized flag will be set.

15. The method of claim 7, wherein incoming probe packets from the same source have a train size field that can only be used for the last packet of a train of probes and wherein the train size field will be set to the number of packets that were immediately sent before this packet incremented by one.

16. The method of claim 7, wherein the remainder of the incoming probe packets from the same source will be filled with random data.

17. The method of claim 7, wherein the noise from the sink will be re-sent every 10 ms until source disconnects or up to 200 ms.

18. The method of claim 7, further comprising using a Traffic Control (“

TC”

) api to create a flow to mark with Differentiated Service Code Point (“

DSCP”

) and tag with 802.1p the traffic with priority values.