Finding latency through a physical network in a virtualized network

Patent metadata

Field	Value
Publication number	US-9596159-B2
Application number	US-201514788398-A
Country	US
Kind code	B2
Filing date	Jun 30, 2015
Priority date	Jun 6, 2012
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

Techniques are described for determining latency in a physical network that includes a number of network devices over which packets travel. A virtual network controller receives a plurality of messages from a plurality of network devices in a network, each of the messages including a packet signature comprising a hash of an invariant portion of an original packet that uniquely identifies the original packet, an identifier of one of the plurality of network devices from which the respective message was received, and a timestamp indicating a time an original packet was processed by the network device from which the respective message was received. The virtual network controller determines a latency of a physical network path in the network based on analysis of contents of the identified messages having a common packet signature.

First claim

The invention claimed is:

1. A method comprising:
receiving, from a virtual network controller, by a network device having a virtual network agent and a virtual network switch of a plurality of interconnected virtual network switches connected to the virtual network controller by an overlay network, information specifying packet characteristics of packets to be analyzed and a time period during which to apply the packet characteristics;
in response determining that a time the information is received is later than the time period during which to apply the packet characteristics, ignoring, by the virtual network agent, the received information; and
in response to determining that the time period during which to apply the packet characteristics has not passed:
installing, by the virtual network agent and based on the information, a packet classifier to the virtual network switch;
responsive to determining that a received packet matches the specified characteristics, by the virtual network agent, determining a hash of an invariant portion of the packet that uniquely identifies the packet to obtain a packet signature; and
forwarding, to the virtual network controller, a message that specifies: (1) the packet signature, (2) an identifier of the network device, and (3) a timestamp indicating a time the packet was processed by the network device.

2. The method of claim 1 , wherein the identifier of the network device comprises an identifier of the virtual network switch.

3. The method of claim 1 , wherein the invariant portion of the packet comprises a payload of the packet.

4. The method of claim 1 , wherein the received information specifies the time period during which to apply the packet characteristics by specifying a start time and an end time.

5. The method of claim 1 , further comprising disabling the installed packet classifier at the specified end time.

6. The method of claim 1 , wherein the packet characteristics comprise a source address and destination address of the packets to be analyzed.

7. A network device comprising:
a virtual network agent configured to receive, from a virtual network controller, information specifying packet characteristics of packets to be analyzed and a time period during which to apply the packet characteristics;
a virtual network switch of a plurality of interconnected virtual network switches connected to the virtual network controller by an overlay network,
wherein the virtual network agent is configured to, in response to determining that a time the information is received is later than the time period during which to apply the packet characteristics, ignore the received information, and
wherein the virtual network agent is configured to, in response to determining that the time period during which to apply the packet characteristics has not passed:
install, to the virtual network switch, a packet classifier based on the information specifying packet characteristics of packets to be analyzed and the time period;
responsive to determining that a received packet matches the specified characteristics, determine a hash of an invariant portion of the packet that uniquely identifies the packet to obtain a packet signature; and
forward, to the virtual network controller, a message that specifies: (1) the packet signature, (2) an identifier of the network device, and (3) a timestamp indicating a time the packet was processed by the network device.

8. The network device of claim 7 , wherein the identifier of the network device comprises an identifier of the virtual network switch.

9. The network device of claim 7 , wherein the invariant portion of the packet comprises a payload of the packet.

10. The network device of claim 7 , wherein the received information specifies the time period during which to apply the packet characteristics by specifying a start time and an end time.

11. The network device of claim 7 , wherein the virtual network agent is configured to disable the installed packet classifier at the specified end time.

12. The network device of claim 7 , wherein the packet characteristics comprise a source address and destination address of the packets to be analyzed.

13. A non-transitory computer-readable medium storing instructions that when executed cause one or more processors of a network device to:
receive, from a virtual network controller, information specifying packet characteristics of packets to be analyzed and a time period during which to apply the packet characteristics;
in response to determining that a time the information is received is later than the time period during which to apply the packet characteristics, ignore the received information; and
in response to determining that the time period during which to apply the packet characteristics has not passed:
install a packet classifier on the network device based on the information specifying packet characteristics of packets to be analyzed and the time period;
responsive to determining that a received packet matches the specified characteristics, and by the virtual network agent, determining a hash of an invariant portion of the packet that uniquely identifies the packet to obtain a packet signature; and
forwarding, to the virtual network controller, a message that specifies: (1) the packet signature, (2) an identifier of the network device, and (3) a timestamp indicating a time the packet was processed by the network device.

Assignees

• Juniper Networks Inc

Inventors

• Ghose Tirthankar
• Nakil Harshad Bhaskar
• Ramesh Nd

Classifications

• H04L41/12

  Discovery or management of network topologies · CPC title

• H04L69/22

  Parsing or analysis of headers · CPC title

• H04L49/70

  Virtual switches · CPC title

• H04L43/028

  by filtering · CPC title

• H04L45/586

  of virtual routers · CPC title