You are here

What is the speed of the optical module? How to choose?

Submitted by yunseo on Tue, 08/23/2022 - 17:46

  With the rapid growth of traffic,the data center has been upgraded and expanded on a large scale,so people's demand for optical modules is also increasing.In order to meet the needs of different rate networks and application environments,optical modules with different transmission rates are available in the market.Since some Xiaobai users who have just entered the communication industry do not know how to check the rate of the optical module,this article will briefly describe the method of checking the rate of the optical module and how to select it.

  What are the optical module rates?What do you think?

  The optical module rate refers to the number of bits(bits)of data transmitted per second,in MB/s and GB/s.At present,the speed of optical modules in the market generally ranges from 100MB/s to 400gb/s.The common transmission rates are 100MB/s,1GB/s,10Gb/s,25gb/s,40Gb/s,100GB/s and 400gb/s.According to the different transmission rates,the optical modules can be divided into 100base optical modules(i.e.,100m optical modules),1g optical modules(i.e.,gigabit optical modules),10G Optical Modules(i.e.,10G Optical Modules),25g optical modules,40g optical modules,100g optical modules and 400g optical modules.Then,how to identify the speed of optical modules with different transmission rates?The viewing method is as follows:

  Method 1

  The most intuitive and fast way to check the optical module speed is to check the model name on the optical module label.The model name on the optical module label generally contains the basic parameters such as the package form,speed,wavelength and transmission distance of the optical module.Therefore,when we get the optical module,we can first check the model name of the optical module to identify its speed.For example,the model name of the fast(FS)10G Optical module is sfp-10gsr-85,where 10g means its transmission rate is 10Gbps.

  10G Optical module

  The naming rules of different manufacturers may be different,but the meaning of the code is basically the same.Users who are not clear about this naming rule can refer to the following table:

  SFP represents the packaging form of optical module,Ge represents the rate of Gigabit,LH represents the transmission distance of long distance,and SM represents the transmission mode of single mode.

  Method 2

  If the label of the optical module is accidentally lost,we can initially judge the package type and speed of the optical module through its appearance,and then obtain the speed of the optical module by reading the DDM information of the optical module.

  1、Determine the package type of optical module

  Compared with the optical modules developed in the early stage,the current optical modules present small-size characteristics.Taking the fast(FS)optical module as an example,we will first teach you how to judge the package type of the optical module according to its size.

  (1)SFP series optical modules(i.e.100M/1g/10g/25g)have the same size as SFP series optical modules,for example,the appearance and size of Gigabit modules and 10g modules are the same.The size aspect ratio of SFP series optical module is 56.5*13.9mm,and the pull ring is short and attached to the optical module shell.The early 10g XFP/x2/xenpak optical module is larger than the SFP series optical module,with length width ratio of 77.7*8.5mm,91.1*36mm and 115.2*36mm respectively.The pull ring of XFP optical module is the shortest,while the X2/xenpak optical module has no pull ring.

  (2)Qsfp series optical modules(i.e.40g/100g)have the same size as qsfp series optical modules,such as 40g qsfp+optical modules and 100g qsfp28 optical modules.The dimension aspect ratio of qsfp series optical module is 78*18.35mm.Compared with SFP series optical module,its pull ring is longer and extends outside the shell.The size of the early 100g CFP/cfp2/cfp4 optical module is larger than that of the qsfp series optical module.Its length width ratio is 126.79*13.6mm,107.5*41.5mm and 92*21.5mm respectively,and there is no pull ring design.

  (3)Qsfp-dd series optical module(i.e.400g)the size of qsfp-dd series optical module is slightly larger than that of qsfp optical module,with an aspect ratio of 92.9*16.42mm.Its pull ring also extends outside the shell,but is shorter than that of qsfp series optical module.

  In general,we can distinguish the package and speed of the optical module from its size and pull ring length.The common SFP series optical modules have the smallest size and the shortest pull ring.The qsfp-dd optical module has the largest size and the pull ring is longer than the SFP series optical module.The qsfp series optical module has the smallest size and the longest pull ring.

  Optical module package type

  2、Read optical module DDM information

  After the package type and speed of the optical module are preliminarily identified by its appearance,the speed can be obtained by reading the DDM information of the optical module.The optical module DDM information includes parameter information such as optical module type,transmission rate and center wavelength.After the user inserts the optical module into the switch,the user can read the DDM information on the switch to view the rate of the optical module.Take Huawei switch as an example:

  Execute the command display translator[interface interface type interface number|slot slot ID]to view the optical module information on the device interface.As shown in Figure 1000_ Base means that the speed of the optical module is 1Gbps.

  Read optical module DDM information

  However,not all optical modules support querying DDM information.It is best to confirm whether the optical module has this function before querying.

  How to select different speed optical modules

  The packaging form,transmission distance and application range of different rate optical modules are different,so the selection needs to be based on the actual application environment.The following table is an introduction to the main application scope of different speed optical modules:

  In addition to considering the actual application environment,it can also consider the port rate and package type of equipment(such as switches).The port rate of the equipment shall be the same as that of the optical module.However,the equipment with the same port rate also has ports of different package types.Therefore,it is also necessary to consider whether the equipment is compatible with the optical module.
module synonym
sfp transceiver
optical transceiver