Q & A: More about SH Link’s Optical transceivers

From time to time, we receive different questions about Optical Transceivers from our customers. their questions may be yours, thus, we conclude some and list here for your reference:

1: Q: Is SH optical module MSA (Multi-Source Agreement) compatible?

    A: Yes, all our SFP Modules comply with MSA.

2: Q: Will the module work if we don’t use DDM funtion?

     A: The module will still work well no matter you use DDM or not. DDM is meant that you can read and monitor the module working status by managed siwtch.

Tip: DDM is digital diagnostic monitoring, it’s functions are as follows:
             a.Monitoring the working temperature
             b.Monitoring the working voltage
             c.Monitoring the working current
             d.Monitoring the TX and RX Power
             e.Show the factory information of the optical transceiver
             f.Prompt warning/alarm

3: Q: Whether SH optical transceivers can be applied on switch made by our own?

     A: If there is no special code, such as Cisco, Huawei, HP… SH Link’s optical transceivers can work with general switches.

4: Q: In SH optical transceiver datasheet, why I cannot see A0L and A2L information?

     A: In our datasheet, A0H and A2H information are shown. A0L and A2L information are usually set by the factory and can not be changed by customers, so it will not show in the datasheet.

5: Q: What is “Stressed Sensitivity”? What is the difference between “Receiver Sensitivity” and “Stressed Sensitivity”?

     A: Receiver Sensitivity (Unstressed) is the amount of power required to maintain a synchronized link within the BER as per FC-PI or IEEE 802.3 standards.

          Stressed receiver sensitivity (SRS) is the same as unstressed but with a link operating at line-rate. 

Generally, the transmit power of the sending side minus the link loss budget needs to sit between the stressed receiver sensitivity and maximum input power. If the power level falls below the SRS the Bit Error rate will increase.

Receiver Sensitivity
• Sensitivity: the minimum optical input power to the receiver for which it will deliver an acceptable Bit Error Rate (BER).
• Overload: the maximum optical input power to the receiver for which it will deliver an acceptable BER. Overload can also be defined by an acceptable limit on jitter.
• Dynamic Range: the range of optical input powers for which the receiver will deliver acceptable performance.

Stressed Receiver Sensitivity (SRS)
• A stressed transmitter test signal is created that includes vertical and horizontal eye closure.
• The particular optical standard (Fibre Channel or Ethernet) typically describes how the stress is created and how much vertical and horizontal eye closure is required.
• The receiver is then tested with this signal to ensure that it meets the specified BER.

6: Q: Why does 155Mbps SFP show as 100Mbps when we test it?

     A: 100M is in Ethernet and 155M is in SONET/SDH, these are two different protocols. Our 155M SFP maximum supports 155Mbps, whether it showing as 155M or 100M depends on the switch.

For more questions, you can contact us anytime: support@shlinkco.com

We’ll update such information now and then, so if you have any opinions, do not hesitate to contact us. Sharing is valuable for both of us. 🙂