Method and device for detecting 1588 time error between network elements

Patent metadata

Field	Value
Publication number	US-9331837-B2
Application number	US-201214356205-A
Country	US
Kind code	B2
Filing date	Apr 18, 2012
Priority date	Nov 30, 2011
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A method and a device for detecting a 1588 time error between network elements are disclosed. The method includes: a 1588 time network is established for an entire network; when it is required to detect a 1588 time error between a network element and its opposite network element, the network elements transmit, probe packets, each including a local timestamp to each other; and the network element receiving a probe packet calculates, according to a preset time difference algorithm, a time difference between the local timestamp and the timestamp in the probe packet, determines, according to the time difference, whether there is a failure in a detection path, and reports an alarm when there is a failure in the detection path. The disclosure prevents erroneous time transmission due to the time error, thus ensuring the network stability.

First claim

The invention claimed is:

1. A method for detecting a 1588 time error between network elements, the method comprising:
establishing a 1588 time network for an entire network;
when a detection of a 1588 time error between a network element and an opposite network element of the network element starts, transmitting between the network element and the opposite network element, probe packets each including a timestamp;
calculating, by the network element receiving a probe packet from the opposite network element according to a preset time difference algorithm, a time difference between a local timestamp and the timestamp in the probe packet; and
determining, according to the time difference, whether there is a failure in a detection path and when there is a failure in the detection path, reporting an alarm.

2. The method according to claim 1 , further comprising:
when the network element and the opposite network element on which the 1588 time error is to be detected are not adjacent network elements, configuring, according to a time path between the network element and the opposite network element, a detection path for current detection.

3. The method according to claim 2 , wherein:
the probe packet is transmitted/received between the network element and the opposite network element through a passive port or a master port; or
the probe packet is transmitted between the network element and the opposite network element in a Transparent Clock (TC) mode.

4. The method according to claim 1 , wherein:
the probe packet is transmitted/received between the network element and the opposite network element through a passive port or a master port; or
the probe packet is transmitted between the network element and the opposite network element in a Transparent Clock (TC) mode.

5. The method according to claim 1 , wherein the time difference algorithm is implemented by subtracting the timestamp in the probe packet from the local timestamp.

6. The method according to claim 1 , wherein the determining, by the network element, whether there is a failure in a detection path comprises:
determining whether the time difference is greater than a preset time difference threshold; and
when the time difference is greater than the preset time difference threshold, indicating there is a failure in the detection path.

7. A method for detecting a 1588 time error between network elements, the method comprising:
establishing a 1588 time network for an entire network;
when a detection of a 1588 time error between a network element and an opposite network element of the network element starts, transmitting between the network element and the opposite network element, probe packets each including a timestamp;
calculating, by the network element receiving a probe packet from the opposite network element according to a preset time difference algorithm, a time difference between a local timestamp and the timestamp in the probe packet;
determining, according to the time difference, whether there is a failure in a detection path and when there is a failure in the detection path, reporting an alarm; and
when the network element and the opposite network element on which the 1588 time error is to be detected are not adjacent network elements, configuring, according to a time path between the network element and the opposite network element, a detection path for current detection, wherein:
when the 1588 time is ETH1588, the detection path configuration is implemented by configuring a Virtual Local Area Network (VLAN) switched domain among network elements in the time path by means of layer 2 unicast; and
when the 1588 time is IP15888, the detection path configuration is implemented by configuring Internet Protocol (IP) routing on network elements in the time path by means of layer 3 unicast.

8. The method according to claim 7 , further comprising:
before the network element calculates the time different, determining whether the timestamp in the probe packet is balanced and symmetric; and
when the timestamp in the probe packet is unbalanced or asymmetric, performing asymmetry compensation on the timestamp in the probe packet.

9. The method according to claim 8 , further comprising:
before the network element transmits the probe packet to the opposite network element, transmitting hello information to the opposite network element; and
after receiving Resp information returned by the opposite network element, transmitting the probe packet to the opposite network element at a preset transmission rate.

10. A method for detecting a 1588 time error between network elements, the method comprising:
establishing a 1588 time network for an entire network;
when a detection of a 1588 time error between a network element and an opposite network element of the network element starts, transmitting between the network element and the opposite network element, probe packets each including a timestamp;
calculating, by the network element receiving a probe packet from the opposite network element according to a preset time difference algorithm, a time difference between a local timestamp and the timestamp in the probe packet;
determining, according to the time difference, whether there is a failure in a detection path and when there is a failure in the detection path, reporting an alarm before the network element calculates the time different, determining whether the timestamp in the probe packet is balanced and symmetric; and
when the timestamp in the probe packet is unbalanced or asymmetric, performing asymmetry compensation on the timestamp in the probe packet.

11. The method according to claim 10 , further comprising:
before the network element transmits the probe packet to the opposite network element, transmitting hello information to the opposite network element; and
after receiving Resp information returned by the opposite network element, transmitting the probe packet to the opposite network element at a preset transmission rate.

12. A device for detecting a 1588 time error between network elements, the device comprising:
a processor; and
a memory for storing instructions executable by the processor;
wherein the processor is configured to:
establish a 1588 time network,
when a detection of a 1588 time error between a network element and an opposite network element of the network element starts, transmit between the network element and the opposite network element, probe packets each including a timestamp,
calculate, according to a preset time difference algorithm, a time difference between a local timestamp and the timestamp in the probe packet, and
determine, according to the time difference, whether there is a failure in a detection path, and report an alarm when there is a failure in the detection path.

13. The device according to claim 12 , wherein:
the processor is further configured to:
provide a user with an interface for setting a transmission rate and store user setting and when the network element and the opposite network element on which the 1588 time error is to be detected are not adjacent network elements, configure, according to a time path between the network element and the opposite network element, a detection path for current detection;
before transmitting the probe packet to the opposite network element, transmit hello information to the opposite network element;
before calculating the time different, determine whether the timestamp in the probe packet is balanced and symmetric and when the timestamp in the probe packet is unbalanced or asymmetric, perform asymmetry compensation on the timestamp in the probe packet; and
determine whether

Assignees

• Xu Jianxin
• He Li
• Zte Corp

Inventors

• Xu Jianxin
• He Li

Classifications

• H04L7/0016 Primary

  correction of synchronization errors · CPC title

• H04J3/14 Primary

  Monitoring arrangements {(for SDH/SONET rings H04J3/085)} · CPC title

• H04L43/106

  using time related information in packets, e.g. by adding timestamps · CPC title

• H04J3/0667

  Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864) · CPC title

• H04L41/064

  involving time analysis · CPC title