Tag Archives: SFP Transceiver

A Glance At Cisco Single Mode SFP Specification

SFP(small form-factor pluggable) transceivers compact, hot-pluggable transceiver used for bothtelecommunication and data communications applications. They are an interface with a motherboard, router, switch or optical media converter. Link connection into a fiber optic or copper cabling. SFP transceivers are designed to support SONNET, Fiber Channel, Gigabit Ethernet or similar standards. There are both multi-mode and single mode SFP transceiver types. There are also many vendors manufacturing SFP transceivers like major brand Cisco. Cisco SFP transceivers also have Cisco multi-mode SFP and Cisco single mode SFP transceiver types. The following text will mainly focus on Cisco single mode SFP.

cisco singlemode sfp

An Outline of Cisco SFP Transceiver

The industry-standard Cisco SFP transceivers are mainly used to link equipment in telecommunication and data communications like switches and routers. They support applications like 2G/4G Fiber Channel, SONET/SDH Network, Gigabit Ethernet, High-speed computer links, and with CWDM and DWDM interfaces. Cisco SFP have many types, such as 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, 1000BASE-EX, 1000BASE-ZX, or 1000BASE-BX10-D/U on a port-by-port basis. Among them, 1000BASE-T SFP operates on standard Cat 5 UTP copper cabling of link lengths up to 100 m; 1000BASE-SX SFP only operates on multimode fibers; 1000BASE-LX/LH SFP operates on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers; 1000BASE-EX SFP only operates on long reach standard single-mode fibers; 1000BASE-ZX SFP operates on long-reach standard single-mode fibers; 1000BASE-BX10-D and 1000BASE-BX10-U SFP operate on a single strand of standard SMF. So we can see that Cisco single mode SFP consists of 1000BASE-EX SFP, 1000BASE-ZX SFP, 1000BASE-BX10-D and 1000BASE-BX10-U SFP.

cisco sfp

A Sketch of Cisco Single Mode SFP Transceiver

Cisco single mode SFP has much tighter tolerances for optics used. The core is smaller and the laser wavelength is narrower. This means that SMF has the capability for higher bandwidth and much longer distances in transmission. Cisco single mode SFP (SMF SFP) work mainly in 1310nm and 1550nm wavelength and is mostly used in long distances transmission environment reaching 2km, 10km, 40km, 60km, 80km and 120km. The color coded bale clasp and color arrow on label are generally blue, yellow or purple. And the color of compatible fiber optic patch cord is yellow.

Cisco Single Mode SFP Specification

Here is a specification chart of Cisco single mode SFP transceivers.

Model Number Transceiver Description
GLC-ZX-SM= 1000BASE-ZX SFP transceiver module for SMF, 1550-nm wavelength, dual LC/PC connector
GLC-BX-D= 1000BASE-BX10 SFP module for single-strand SMF, 1490-nm TX/1310-nm RX wavelength, single LC/PC connector
GLC-BX-U= 1000BASE-BX10 SFP module for single-strand SMF, 1310-nm TX/1490-nm RX wavelength, single LC/PC connector
GLC-BX40-D-I 1000BASE-BX10 SFP module for single-strand SMF, 1550-nm TX/1310-nm RX wavelength, single LC/PC connector
GLC-BX40-U-I 1000BASE-BX10 SFP module for single-strand SMF, 1310-nm TX/1550-nm RX wavelength, single LC/PC connector
GLC-BX80-D-I 1000BASE-BX10 SFP module for single-strand SMF, 1570-nm TX/1490-nm RX wavelength, single LC/PC connector
GLC-BX80-U-I 1000BASE-BX10 SFP module for single-strand SMF, 1490-nm TX/1570-nm RX wavelength, single LC/PC connector
GLC-BX40-DA-I 1000BASE-BX10 SFP module for single-strand SMF, 1490-nm TX/1310-nm RX wavelength, single LC/PC connector
GLC-2BX-D= Dual-channel 1000BASE-BX10 SFP module for single-strand SMF, 1490-nm TX/1310-nm RX wavelength, two single LC/PC connectors
GLC-EX-SMD= 1000BASE-EX SFP transceiver module for SMF, 1310-nm wavelength, extended operating temperature range and DOM support, dual LC/PC connector
SFP-GE-Z= 1000BASE-ZX SFP transceiver module for SMF, 1550-nm wavelength, extended operating temperature range and DOM support, dual LC/PC connector
GLC-ZX-SM-RGD 1000BASE-ZX SFP transceiver module for SMF, 1550-nm wavelength, industrial Ethernet, dual LC/PC connector
GLC-ZX-SMD= 1000BASE-ZX SFP transceiver module for SMF, 1550-nm wavelength, dual LC/PC connector


From the above introduction, you must have a well understanding about Cisco single mode SFP. When choosing SFP modules, you should consider whether it matches the switch port and the cable you have prepared. If you have multimode cable, then you can choose 1000BASE-SX or 1000BASE-LX/LH SFP. If you use single-mode fiber cable, you should select what I’ve mentioned above. While if your cable is copper category, you have to use 1000BASE-T SFP such as GLC-T SFP. On condition that your budget doesn’t allow you to buy original brand module, you can buy the third-party optics from FS.COM with Cisco, Avago, HP and other compatible brands. All the optics have gone through test for 100% compatibility.

How to Upgrade From 10GbE to 40GbE for Multimode Fiber?

To cope with the never-ending requirement for higher bandwidth, people are looking to migrate from 10G Ethernet to 40G Ethernet, whilst keeping their fiber infrastructure in compliance. However, the ability to migrate from 10G to 40G hinges on knowing the nature and length of the backbone cable. If you don’t know the overall length of the circuit, connector style (LC, 12 or 24 fiber MPO) or the fiber type (OM2, OM3, OM4, SM, etc.), you will trigger some mistakes during the migration. Then the following passage provides instantaneous access to detailed information about upgrading from 10G to 40G over multimode fiber.

Migrating from 10GbE to 40GbE for multimode fiber will require a lot more fibers and a different type of connector. Because 10G SR transceivers require 2 fiber strands per 10G link, 40G SR4 and CSR4 transceivers require a minimum of 8 fiber strands, and often 12 fiber strands in practice. The reason for this requirement is that 40G SR4 and CSR4 transceivers use 4 parallel fiber pairs (8 fiber strands) at 10Gbps each for a total of 40G full duplex. What’s more, 10G SR transceivers operate over dual-fiber multimode fiber (MMF) with LC connectors, and 40G SR protocols, such as SR4 and CSR4, operate over MMF ribbon with MPO connectors. As a result, 40G MPO-based SR4 transceivers cannot reuse aggregation fiber infrastructure built for 10G connectivity requiring fiber cabling infrastructure to be redesigned and replaced. The following text provides two cost-effective solutions for upgrading to 40G network.

Scenario 1—if upgrading from 10G to 40G, one or more of the LC Duplex cassette(s) can be replaced with 12 MPO adapters. The MPO adapters are designed to fit in the same opening as the cassettes. This easy upgrade path uses the 8-fiber harness cable to connect to the 10G SFP+. From Figure 1, we can see that 4 10G SFP+ modules like SFP-10GB-SR  are connected with MPO adapter by MTP harness cable. It does not require any additional space and reuses the same patch panels. Additional 12-fiber cable assemblies (or any fiber counts in multiples of 12 fibers) are provided as needed for backbone or horizontal cabling.

10G SFP+ module connects MTP harne

Scenario 2—if it is required to add some 40G connections while retaining the 10G connections, like Figure 2 shows, use one MPO/MTP LGX Cassette to connect four 10G SFP+ links. Then a Type-B female MPO/MTP trunk cable should be used between the cassette and 40G QSFP+ transceiver. QSFP+ transceiver like QSFP-40G-SR4 is needed here to provide a cost-effective solution for smoothly migrating to 40G connectivity.

one MPO LGX Cassette to connect four 10G SFP+ links

Recommended Information
At the end of the passage, I want to stress some factors that you should take into consideration when upgrading from 10G to 40G for multimode fiber.

  • Media type—the type of cable and connector, such as LC or MPO, 12 or 24 strand fiber cable.
  • Wiring pattern—12 and 24 strand cables won’t have the same wiring patterns, and it’s essential to track the wiring pattern coming out of trunk cable A and know whether it’s compatible going into trunk cable B.
  • Performance level—whether it is a 40 or 100GbE cable, OM3 or OM4. This also provides details about the expected performance of a cable assembly.
  • Insertion and cleaning—the number of insertions is used as an indicator of how often a particular fiber should be cleaned – if the fiber has been re-connected four or five times, it’s a good idea to clean it to remove dust or oil.
  • Length of cable—the intelligent connectors enable the database to add up all the components on a circuit and see if the circuit exceeds the length budgets for 10, 40, or 100GbE. Even if the circuit segments are different lengths, it will base the length determination on the media type and expected performance level.

To upgrade from 10G to 40G directly, there are several factors we should look to. And I hope the above two scenarios will be helpful to you. Fiberstore provides a variety of 40G cables and parallel QSFP+ transceivers to help you achieve 10G to 40G migration easily. We also offer all kinds of specification mulitmode or single-mode MTP to LC break out cables. For more information, please feel free to contact us.

Cisco GLC-SX-MM/GLC LH SM Transceiver Compatible 1000BASE-SX SFP Transceiver Module

SFP (Small Form-Factor Pluggable Plus) fiber transceiver modules make the fiber optic network or fiber-Ethernet network easier to upgrade or maintain, users can replace a single SFP module during the process instead of replace the whole board with many modules on it. SFP transceiver are different types working with different wavelength for various kinds of distances. SX SFP use 850nm for max 550 meters, LX SFP use 1310nm for max 10km, ZX SFP could reach 80km. There is also copper SFP that use a RJ45 interface. DOM function for SFP is optional, it help users detect real time SFP working status SFP transceiver is an innovative, next-generation transceiver module.

Cisco SFP Modules is also hot plugable, it is an upgraded version fiber optic transceiver, it represents the trend to be smaller and more flexibility. Cisco Compatible SFP includes a wide range of the transceivers with different working wavelength and distance. In the following list I will introduce you some information about GLC SX MM Transceiver and GLC LH SM Transceiver.

GLC SX MM Transceiver


Cisco GLC-SX-MM is 1000Base-SX SFP fiber optic transceiver for multimode fiber and it works at 850nm wavelength. GLC SX MM SFP is hot swappable module that fit for Gigabit Ethernet port or slot and link the port with the network, whose interface is dual LC for optical. GLC SX MM is about 1.3 cm x 5.7 cm x 0.9 cm in dimension, and 75g in weight. The GLC SX MM transceivers are compatible with SFP Multi-Source Agreement (MSA), 1000Base SX standard for Gigabit Ethernet and SFF-8472.

The GLC SX MM transceiver consists of three sections: a VCSEL laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. All modules satisfy class I laser safety requirements. The GLC SX MM SFP transceivers are high performance, cost effective modules supporting data-rate of 1.25Gbps and 550m transmission distance with MMF.

GLC LH SM Transceiver

Cisco GLC-lH-SM SFP fiber optic transceiver working at 1300nm wavelength, GLC LH SM is suit for both multimode optical fiber and single mode optical fiber, it is small size transceiver with LC interface and it is hot swappable, easy to use, no need further configuration. GLC LH SM is used in Gigabit network and its max working distance is 10km over SMF or 550meters over MMF, data transfer rate at 1Gbps and it works based on IEEE 802.3z standards.
The GLC LH SM transceiver consists of three sections: a FP laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. All modules satisfy class I laser safety requirements.
SFP fiber optic transceivers are upgraded version of its former GBIC transceivers, Cisco SFP transceiver adopt LC interface and its size is only about half of GBIC, thus Cisco SFP fiber transceivers fit for dense installations.

1000BASE-X Media Components

The following set of media components are used to build a 1000BASE-X fiber optic segment:

1. Fiber optic cable

2. Fiber optic connectors

Gigabit Ethernet fiber optic segments use pulses of laser light instead of electrical currents to send Ethernet signals. This approach has several advantages. For one thing, a fiber optic link segment can carry Gigabit Ethernet signals for considerably longer distances than twisted-pair media can. The standard specifies that a full-duplex 1000BASE-LX segment must be able to reach as far as 5,000 meters (16,404 feet, or a little over 3 miles). However, most vendors sell “long haul” versions of 1000BASE-LX equipment that are designed to reach as far as 10 km (6.2 miles) on single-mode fiber. Vendors have also developed “extended reach” versions of 1000BASE-LX single-mode interfaces that can send signals over distances of 70-100 kilometers or more.

In large, multibuilding campuses, the fiber distances can add up fast, as the fiber cables may not be able to take the most direct route between buildings on the campus and a central switching location. Therefore, these long-reach transceivers can be quite useful. The LX interfaces are essential when it comes to building metropolitan area network(MAN) links, in which Gigabit Ethernet is used to provide network services between sites on a city-wide basis.

Fiber optic cable

Both 1000BASE-SX and 1000BASE-LX fiber optic media segments require two strands of cable: one for transmitting and one for receiving data. The required signal crossover, in which the transmitting and one for reciving data. The required signal crossover, in which the transmit signal (TX) at one end is connected to the receive signal (RX) at the ther end, is performed in the fiber optic link. (Related products in: 10GBASE-LR XFP)

Maximum segment lengths for 1000BASE-SX and 1000BASE-LX are dependent on a number of factors. Fiber optic segment lengths in the Gigabit Ethernet system will vary depending on the cable type and wavelength used.

Fiber optic connectors

The original standard recommended the use of duplex SC fiber optic connectors for both 1000BASE-SX and 1000BASE-LX fiber optic media segments. Figure 1 shows a duplex SC connector. Although the standard can recommend a connector, vendors can use other fiber optic connectors as long as they are not forbidden in the standard. For examle, when the 1000BASE-X media systems first became available, vendors used the compact MT-RJ connector on 1000BASE-SX ports.

21   Figure 1, Duplex SC connector
Figure 2 shows the MT-RJ connector, which provided both fiber connections in a space the size of an RJ45 connector. Because the MT-RJ connector takes up about half the space required by the SC connectors, this allowed vendors to provide more 1000BASE-SX ports on swithch.

22 Figure 2, MT-RJ connector


1000BASE-X transceivers

Some vendors used the Gigabit Interface Converter (GBIC), which was an earlier form of transceiver module that allowed the customer to support either the 1000BASE-SX or 1000BASE-LX media types on a single port. The GBIC is a small, hot-swappable module that provides the media system signaling components for a Gigabit Ethernet port.

More recently, vendors have developed a small form-factor pluggable (SFP) transceiver, which can be purchased to support several different kinds of Ethernet fiber optic media systems.

The SFP Transceiver is a small module the plugs into a seitch port and uses a small fiber optic connector called the LC connector. Figure 3 shows the smaller LC fiber optic plug, which is used for connections to SFP fiber optic transceivers.


23Figure 3, Duplex LC fiber optic plug