Ixia IEEE 1588 test plan

IXIA 测试1588

Ixia IEEE 1588 Test Plan

随着IEEE 1588作为一种网络时钟同步技术被随着越来越多的网络设备支持，实现对该技术的测试变得越来越紧迫。本文介绍Ixia如何实现对IEEE 1588的测试。

Ixia solution current Features

– IEEE 1588 version 2.2 in IPV4 (multicast) support – Two-step clocks support

– Mixed (non-PTP) traffic along with PTP traffic. Ixia ports will have the

ability to throttle transmit based on flow control packets being received. – 1 clock per port support

– Ports can be configured in Master or Slave mode manually.

– Histogram reporting Slave clock OFFSET from master is provided in

the form of plot along with PTP messages transmitted and received. – – – –

Aggregate statistics

Session/Per Interface stats

Per Interface configuration via protocol interfaces Negative testing

Programmable follow up messages in % of sync messages. See

how dropping 10-90% (sending 100% of sync messages) of follow-up messages affects the DUT

Sending follow-up messages with a bad packet

Purposely send data with timestamps that include jitter (Trying

to force sync failure)

– Ability to compose or decode PTP messages from IxExplore

– Support on LSM1000XMV/XMVR Family of 4, 8, 12 and 16 ports,

ASM1000XMV12X with EEPROM upgrade

– Minimum IXOS requirement: 5.30 EA

Future feature:

– – – – –

Multiple clocks per port Sync-E

Status per clock

Best Master algorithm support Peer Delay mechanism support

IXIA 测试1588

Suggest test topology:

1. 功能测试

Port 1 and port 2 are connected back to back

Port 11 and port 12 are connected to the two end of one network as following:

IXIA 测试1588

Step 2

对每个interface配置PTP属性

点击“PTP edit”目录栏的Edit按扭进行每个接口的PTP熟悉配置。

Master clock port:

如果选中，接口工作在 master模式；没有选中，接口工作在slave模式。

其中“message intervals”里面的3个值定义了PTP里面的Sync, Delay request, Annouce

IXIA 测试1588

报文周期发送时间, 前缀Log表示结果以幂来表示。因此3类报文缺省interval的时间都为1秒。

Announce receipt timeout:

announceInterval that must pass without receipt of an Announce message Number of

before the Announce Receipt Timeout event occurs

在slave 模式的接口上，建议修改为2。用缺省值0无法成功协商。

Step 3.

确认接口工作在正确的master/slave模式下面。

IXIA 测试1588

Clock offset/time slope/mean path delay 3个值给出了时钟的统计值。 这些参数的解释如下：

Anup Jethra：

From my understanding, each of 703s is boundary clock. If that is the case then first 703 will sync to Ixia Master clock. Second 703 will sync to first 703 and so on. Ixia slave port will sync to third 703. On Ixia slave port, mean path delay is the one between third 703 and Ixia slave. Clock offset is the overall clock offset between Ixia Master and Ixia Slave accounting for the entire PTP path.

If 703s were transparent clock, then Mean path delay would be the total path delay between Ixia master and Ixia slave - residence time between in each of 703s. In other words, mean path delay would be delay between Ixia Master and first 703 + delay between first 703 and 2nd 703 + delay between 2nd 703 and 3rd 703 + delay between 3rd 703 and Ixia slave. Clock offset would still be between Ixia Master and Ixia slave.

Time slope is between Ixia master and Ixia slave for both cases.

对于slave模式的接口，可以记录Clock offset/time slope/mean path delay 3个值变化的历史值。Clear -> start->save, 将记录结果存放到用户指定的excel文件。

IXIA 测试1588

PTPHistogram-2200000000000000_0.xl

该ASM1000XMV12卡的IxExplore

的配置保存如下。

ASM

XMV12_1588.zip

可以将XM机框链接AFD模块，将GPS时钟作为机框的时钟源。

这种情况下，Ixia master端口发出的PTP报文的timestamp就是GPS的timestamp。

2. Negative test:

修改master mode下的接口里面的Negative testing parameter参数，然后在PTP discovery information里面查看是否会对时钟有影响。 PTP discovery information里面的报文统计可以通过IxExplore里面的“clear statistics”清除。

IXIA 测试1588

3. 编辑PTP报文发送

除了在IxRouter里面可以创建PTP接口进行测试外，在IxExplore里面可以定义无状态的PTP格式的数据流进行功能测试。

To activate the PTP feature, begin at the Frame Data tab of the Stream Properties

Note: When a stream is configured as PTP, the Destination Address on the Streams properties DA/SA tab will be deactivated and grayed out, due to the fact that Ethernet, IPv4 and UDP transmission of PTP packets relies on a reserved Destination Address.

2. Choose Ethernet II, IPv4, and PTP/UDP/IP. (A Warning message will occur, regarding frame size.)

3. Change the Frame Size to 128 (so that it is long enough to accommodate the PTP header). 4. Click Edit.

RTP statistics:

PTP port-level statistics can be collected by checking in the Statistics tab

IXIA 测试1588

IXIA 测试1588

Appendix A- Protocol interface help message

Area

Characteristics

Field

Domain Number

Description

The domain is identified by an integer in the range of 0 to 255.

Priority 1

A user configurable designation that a clock belongs to an ordered set of clocks from which a master is selected. A user configurable designation that provides finer grained ordering among otherwise equivalent clocks. A specific PTP port on a PTP node

Defines the clock offset in nanoseconds. Master sends PTP messages with Start Offset added to the clock. Identifies a clock

Priority 2 Port Number Start Offset(s) Clock Ident …… 此处隐藏：7273字，全部文档内容请下载后查看。喜欢就下载吧 ……