How To Select A Right Cisco 10G SFP + Optical Module?

Aug 17 , 2022 1021

As we all know, the 10G fiber networks are already common in telecommunication networks, and 10G switches are being widely used by users. According to statistics, Cisco switches are the most common one. If you are using a Cisco switch, you will need to select a Cisco compatible optical module, such as an SFP optical module or an SFP+ optical module. If you don't know how to transfer between optical and electrical signals, please read the following carefully and it will help you.

The 10G fiber network is now mature. For different 10G network applications, the 10G IEEE standard has different standards. Before you purchase a Cisco 10G SFP+ optical module, you should first understand the 10G IEEE standard and the naming rules for Cisco optical modules.

The naming of Cisco optical modules is not a random arrangement of letters and numbers, but a strictly logical naming system. By understanding these naming rules, you can quickly determine the type, speed, transmission distance, and media type of the optical module.

Basic structure of Cisco optical module naming

The naming of Cisco optical modules usually consists of several parts, mainly containing the following elements:

SFP-XXXX-TYPE. the type of SFP module, which refers to a small pluggable optical module;

XXXX indicates the speed or transmission distance of the module (such as 10G, 40G, 100G, etc.);

TYPE indicates the specific fiber type, transmission distance or wavelength.

To help you understand, let's take a few common optical modules as examples:

SFP-10G-SR: 10G speed, short range (Short Range).

SFP-10G-LR: 10G speed, Long Range.

SFP-10G-ZR: 10G speed, Extended Reach.

10G IEEE standard

The IEEE defines different transmission distances and transmission media in the 10G standard. For example, a 10GBASE-SR optical module can transmit 300 meters in short distance in OM3 multimode fiber, while a 10GBASE-LR optical module can transmit over 10 kilometers in a single mode fiber. It can also be used for standards for 10G transmission in copper cables such as 10GBASE-CR and 10GBASE-T. The table below lists the most commonly used 10G network transmission standards.

Cisco 10G SFP+ Optical Module Product Name

The naming system for Cisco 10G SFP+ optical modules is closely related to IEEE standards. Here are a few examples of Cisco 10G SFP+ optical module names for a better description.

For regular 10G SFP+ optical modules, Cisco uses standard keyword naming conventions. For special optical modules, Cisco has established a mature naming system.

For paired BiDi SFP+ optical modules, the letters "D" and "U" indicate the two optical modules used together at each end of the fiber optic link. For example, the SFP-10G-BXD-I & SFP-10G-BXU-I is a pair of BiDi optical modules that support transmission distances of up to 10km. Additional numbers are used to mark the transmission distance of the BiDi optical module. The SFP-10G-BX40D-I and SFP-10G-BX40U-I are a pair of optical modules that support transmission distances of up to 40km.

For CWDM 10G SFP+ and DWDM SFP+ optical modules, the wavelength increases with the part number. For example, the part number of the CWDM-SFP10G-1470 is CWDM SFP+, which has a working wavelength of 1470 nm. If you want a CWDM SFP+ optical module that operates at 1550 nm, the CWDM optical module should have a CWDM-SFP10G-1550. Since all DWDM SFP+ optical modules use a wavelength of approximately 1500 nm, the first two digits 1 and 5 must be eliminated in the product number of the Cisco DWDM SFP+ optical module. For example, the DWDM SFP+ standard optical module DWDM-SFP10G-61.41 has an operating wavelength of 1561.41 nm.

For SFP+ direct-connect high-speed cables and SFP+ active cables, including cable lengths, Cisco names optical modules by integrating IEEE standards and quantities. The Cisco SFP-10G-AOC2M is a 2 meter long 10G SFP+ active cable.

Depending on the application requirements, Cisco offers several types of 10G SFP+ optical modules. Here are some common models and their applicable scenarios:

SFP-10G-SR: It is suitable for short-distance transmission and is usually applied between racks in data centers. Its transmission distance is usually within 300 meters, which is suitable for high-density and low-latency requirements.

SFP-10G-LR: Suitable for long-distance transmission, covering a range of 10 kilometers, widely used for cross-building network connectivity, and suitable for campus network or metro network deployment.

SFP-10G-ER: This module can achieve up to 40km of transmission, and is mainly used for connectivity between enterprises or data centers with wide geographic distribution, suitable for cross-city data transmission needs.

SFP-10G-ZR: The transmission distance can reach up to 80 km, suitable for cross-city high-speed data transmission scenarios, and is usually used for connectivity between Internet service providers or large-scale data centers.

Different module types have their unique advantages, so when choosing one, the decision must be based on the actual needs of your organization. If your data center or enterprise network only requires high-speed transmission over short distances, then SR modules may be sufficient. For businesses that require long distance transmission, LR, ER or even ZR modules are more appropriate.

Advantages of Cisco Compatible SFP+ Optical Modules

In addition to IEEE standards and transmission distances, there are other factors that should be considered when choosing the right 10G SFP+ optical module, such as compatibility and cost.

Although Cisco can give users multiple choices on switches and 10G SFP+ optical modules, not every SFP+ optical module can be used on the Cisco SFP+ interface. Before selecting a Cisco SFP+ optical module, you must ensure that this SFP+ optical module is compatible with the switch.

The second important factor is the cost of SFP+ optical modules. SFP+ optical modules are a small part of the entire fiber network, but SFP+ optical modules are very useful. Cisco original SFP+ optical modules are usually expensive. Therefore, choosing a cost-effective optical module is critical. In fact, the original optical module is not the only choice for users, there are many third-party modules that are compatible with Cisco switches. In general, the price of third-party optical modules is more competitive than the original brand. 

Need Cisco switches SFP+ optical modules? Please feel free to contact linknewnet customer service.