As we all know, the SFP optical transceiver is a hot plug compact component that provides optical fiber connections for optical networks.They support fiber optic switches, which are commonly known as FC switches, SONET/SDH networks, gigabit Ethernet switches, high-speed computer links, and CWDM and DWDM interfaces.When connecting with the switch, the optical signal intensity of the SFP optical transceiver is the key parameter to ensure the normal operation of the whole link.But do you know how to measure the signal strength of the SFP optical transceiver?How to check the signal intensity of SFP optical transceiver in the actual operation?

What is the importance of the signal intensity of the SFP optical transceiver?

In general, the signal intensity of SFP optical transceiver includes Tx power and Rx power.Tx power represents the transmitted power signal, and Rx power represents the received power signal.In general, SFP optical transceiver can work normally only the two values are within a specific range. Take GLC-SX-MM 1000BASE-SX SFP as an example, the range of transmitting power is -3 ~ -9.5dBm, and the range of receiving power is 0 ~ -17dbm.If Tx or Rx is in the range of -30dbm or lower, the signal is not actually sent or received.

The strength of the optical signal directly determines that the network can work normally. If the received power is not strong enough, there will be no signal in the optical link. Therefore,some long-distance transmission scenarios require an optical amplifier to enhance the signal.If the power of the sending end is too strong, it will cause damage to the SFP optical transceiver. So the stability of the optical signal intensity is very important for the stable connection.

How to measure the signal strength of the SFP optical transceiver?

Generally speaking, when we buying the SFP optical transceiver, the power information of the product will be described. There are two methods for measuring the intensity of the optical signal, microwave and dBm. The former uses the power to measure the optical signal strength, and the latter uses the decibel to describe the signal strength. Different vendors may use one of them to describe the power of the signal. For example, Cisco switches typically use dBm to measure power, and Brocade switches use mW (microwave).

There is a conversion formula between the two:

dBm---mW:mW=10dBm/10

mW---dBm:dBm=10*（LogmW）

It should be noted that during the transmission process, the optical signal will attenuate. In order to guarantee the transmission quality, network operators also need to pay attention to the optical transceiver attenuation, which is the acceptable range of optical transceiver

Maximum acceptable signal attenuation of 8Gbps: -13.8dBm

Maximum acceptable signal attenuation of 4Gbps: -15.4dBm

Maximum acceptable signal attenuation for 2Gbps: -18.2dBm

How to view the optical signal strength of SFP optical transceiver supplied by ETU-Link?

Need to make sure whether the SFP optical transceiver is working normally, you can view its data table. Usually, the SFP optical transceiver data table provides key information such as link range, fiber type, output power, and received power.Cisco and Brocade SAN switches provide a command-based interface reference for users to view detailed information about SFP optical transceiver, including SFP optical transceiver speed, serial number, part number, optical signal strength, and so on. (First:Cisco, second:Brocade)

From the above results we can know that cisco and brocade have different ways of marking signal strength.However, both of them provide the current signal intensity and the effective optical signal intensity range of the SFP optical transceiver.As long as the signal intensity of the SFP optical transceiver is within the effective range, the SFP optical transceiver can work normally.

All SFP optical transceivers supplied by ETU-Link have go through strict quality inspection process. In addition, we also provide perfect after-sales service,If you receive the quality problems of the products, you can return them according to the process. We provide three-year warranty service, if you want to know more details, please visit our website: www.etulinktechnology.com