Testing Seven-Speed 400/200/100/50/40/25/10GbE using a Spirent TestCenter dX3 or pX3 QSFP-DD Test Module or Appliance
The first part of this Article addresses initially establishing link, the second part addresses Performance Testing up to 400 Gbps, and lastly the video addresses using the Spirent TestCenter Application's L1 Service, enjoy!
This Article is in reference to the following Test Modules and Appliances:
Datasheet: Spirent dX3 2-Port Seven-Speed 400/200/100/50/40/25/10GbE QSFP-DD Test Module
Datasheet: Spirent dX3 8-Port Seven-Speed 400/200/100/50/40/25/10GbE QSFP-DD Appliance
Datasheet: Spirent pX3 2-Port Seven-Speed 400/200/100/50/40/25/10GbE QSFP-DD Test Module
Datasheet: Spirent pX3 8-Port Seven-Speed 400/200/100/50/40/25/10GbE QSFP-DD Appliance
Spirent now supports CMIS Rev 4.0, however, the main issue you’ll have if any is initially establishing link. Besides no cable being plugged in, the transceiver not being properly inserted, or using an unintended transceiver, this is usually the result of an “emphasis” issue (i.e., Pre-emphasis Tap, Main Tap, and Post-emphasis Tap). So if link comes up initially, then you can skip this first half. But should link fail, try these tips relative to the Port’s Advanced tab:
1) Well first of all wait a few minutes longer, take a break and come back.
2) Auto detect works with Auto Negotiate on the General tab and is the default setting, so that you have already tried.
3) Manual, which disables Auto Negotiate, can be used if Auto detect fails and presents the user with the following preset values: Optical, 0-1 Meter Copper, 2 Meter Copper, and Loopback. Don’t forget to “Apply” after making changes!
4) Advanced also works with Auto Negotiate on the General tab and allows the user to enter the TX deemphasis pre tap, TX deemphasis post tap, and TX main tap swing. Select “Advanced” then select the General tab’s “Link Training Resolved Settings” and select “Apply LT Settings to Port”. But feel free to change these settings yourself if it still doesn’t link. Don’t forget to “Apply” after making changes!
5) See attached below from Spirent engineering which speaks of a “Bathtub” method to find emphasis values.
6) Still not working, please reach out to Spirent Support.
Once you have link, Performance Testing up to 400 Gbps is still conducted as it has always been, just now at faster speeds; and similarly for Emulation. Keep in mind though that scale and supported counters are based on DX3 and PX3 class PGA architecture; see the Datasheet sheet links above. But most users won’t notice any difference from other modules.
Attached and below you see the Maximum Frame Rates for Ethernet table filled in for all higher rates too. Frame sizes listed are those for RFC2544's 7 recommended Ethernet Sizes. The table attached below also allows you to replace "Any#" in column J with a custom # for ‘odd’ frames sizes (i.e., those not specified by RFC 2544).
For a demonstration of using the Spirent TestCenter Application's L1 Service, select the Video Play Button below:
If you need more information on this topic, please reach out to Asim Rasheed.
Series: Essentials of Courses