SFP Transceiver Module Troubleshooting

SFP (small form-factor pluggable) is a compact, hot-pluggable transceiver module used for both telecommunication and data communications applications. With the increasing high speed data transmission demands of people, products, such as SFP+, CFP and QSFP/QSFP+ etc. have shared the market. Nonetheless, SFPs have still played an important role in telecommunication and data communication.
As a widely and commonly used component in data transmission, due to the incorrect operation or other factors, it is hard to avoid facing the faults in using SFP, and sometimes even result in a bad situation and heavy loss. This paper will help you to diagnose the SFP problems (take Cisco for example) and give some resolution tips. I hope it would be acted as a learning tool and a reference source for both new and experienced technicians who work in this field.
To diagnose SFP problems, you can get statistics from the browser interface, the CLI (Command Line Interface) or an SNMP (Simple Network Management Protocol) workstation. The most common SFP problems include these aspects:
.Poor performance
.No connectivity
.Corrupted software
Poor Performance (or Excessive Errors)
Possible Cause:
The possible causes of this problem include that cabling distance is exceeded or port statistics show excessive frame check sequence (FCS), late-collision, or alignment errors.
Reduce the cable length to within the recommended distances.
See your SFP module documentation for cabling guidelines.
No connectivity
Possible Cause:
This problem is most likely related to cabling. Using incorrect or bad cable, or incorrect cable wiring, or STP (Shielded Twisted Pair) checking for possible loops may probably lead to this problem.
Verify the pinouts are correct for the proper application of cables.
Replace the cable with a tested good cable.
Wait 30 seconds for the port LED to turn green.
Corrupted software
The corrupted software here we mentioned include the following three situations.
1.The port is placed in error-disabled state after SFP is inserted.
Possible Cause:
This problem is usually caused by bad or non-Cisco-approved SFP module(ie. the incompatible SFP).
Remove the SFP module from the switch and replace it with a Cisco-approved module. Use the irrdisable recovery cause GBIC-invalid global configuration command to verify the port status, and enter a time interval to recover from the error-disable state. The best advice is to use the Cisco original SFP or 100% Cisco compatible SFP (If you decide to use a third-party SFP, please ensure that your supplier is assured) that is adapted to the switch.
2.Device does not recognize the SFP module.
Possible Cause:
This problem is generally related to the SFP installation. Situations, such as SFP is installed upside dowm or does not snap into the slot can cause this problem.
Verify that the SFP module is not installed upside down.
Remove the SFP module. Inspect for physical damage to the connector, the module, and the module slot.
Replace the SFP module with a known good SFP module.
3.Excessive errors found in port statistics.
Possible Cause:
Bad adapter in attached device or STP checking for possible loops can cause this problem.
Run adapter card diagnostic utility and wait 30 seconds for the port LED to turn green.
Some common error message of Cisco Switch When Using With SFP Module
Error Message: Transceiver module inserted in port
Explanation: The online insertion and removal (OIR) facility detected a newly inserted transceiver module for the interface specified in the error message.
Error Message: INIT_FAILURE: Detected for transceiver module in port, module disabled
Explanation: An initialization failure occurred for the transceiver module for the interface specified in the error message. This condition could be caused by software, firmware, or hardware problem. As a result of the error, the module is disabled.
Recommended Action: Try reseating the module. Hardware replacement should not occur first occurrence. Before requesting hardware replacement, review troubleshooting logs with a technical support representative.
Error Message: NOT_IDENTIFIED: Detected for transceiver module in %s, module disabled
Explanation: The transceiver module for the interface specified in the error message could not be identified and may not be compatible with the interface. The transceiver module specified in the error message contains a transceiver code which could not be correctly interpreted. As a result of the error, the module is disabled.
Recommended Action: Replace the module with a compatible transceiver.
Error Message: UNSUPPORTED-TRANCEIVER: Unsupported SFP transceiver found on board. Warranty/support may void
Explanation: The transceiver module for the interface specified in the error message is not a Cisco supported module. As a result of the error, the module is disabled. When Cisco determines that a fault or defect can be traced to the use of third-party transceivers installed by a customer or reseller, then, at Cisco’s discretion, Cisco may withhold support under warranty or a Cisco support program. In the course of providing support for a Cisco networking product Cisco might require that the end user install Cisco transceivers if Cisco determines that removing third-party parts will assist Cisco in diagnosing the cause of a support issue.

SFP Transceiver Signals and Types

The SFP transceiver holds a Printed track Board that partners with the SFP electronic connector in the service configuration.
A “base transceiver station” (BTS) is a bit of outfits that eases wireless information exchange amid exploiter out fits (UE) and a network. UEs are implements like protable telephones (handsets), Wireless native loop telephones, computers with wireless Internet connectivity.
The network may be that of whatever of the wireless information exchange applications of tools and methods like GSM, CDMA, wireless native circle, WIFI, WiMAX either different ample zone network (WAN) technics.
BTS is as well referenced to like the broadcast center facility (RBS), point B(in 3G Networks) either, plainly, the center facility (BS). For conversation of the 3GPP Long TERM Evolution normal the shortening EnodeB for developed point B is extensively applied.
Though the expression BTS may be appropriate to whatever of the wireless information exchange norms, it is normally related with portable information exchange applications of tools and methods like GSM and CDMA. In this heed, a BTS forms piece of the center facility self-contained system within larger system (BSS) elaborations for configuration administration. It might as well have outfits for encrypting and decrypting information exchanges, range filtrating implements (band go filters), etcetera. Antenas might as well be deemed like parts of BTS in common feel as they some dissimilar turnaround and dissimilar areas of the cell (in the situation of sectorised center stations). A BTS is managed by a progenitor center facility regulator by way of the center facility command purpose (BCF). The BCF is executed like a separate component either even integrated in a TRX in firm center stations. The BCF delivers a transactions and upkeep (OM) link to the network administration configuration (NMS), and organizes operative states of every one TRX, as well like code managing and alert gathering. The fundamental construction and purposes of the BTS stays the similar notwithstanding of the wireless technologies.
RF module – Transceiver modules
An RF Transceiver component includes either a sender and recipient. The track is characteristically developed aimed at Half-duplex working, though Full twofold components are accessible, characteristically at a developed outlay expected to the appended difficulty.
Small form-factor pluggable transceiver – Types
SFP transmitters and receivers are accessible with a diversity of sender recipient kinds, permitting consumers to choose the suitable transceiver for every one link to supply the needed ocular get to over the accessible ocular fiber sort (e.g. Multi-mode fiber either single-mode fiber). Optical SFP components are normally accessible in some dissimilar categories:
For multi-mode fiber, with black either ecru removal lever
SX – 850nm, for a greatest of 550m at 1.25Gbit/s (Gigabit Ethernet) either 150m at 4.25Gbit/s (Fibre Channel). Related product: 1000BASE SX SFP.
For single-mode fiber, with azure removal lever
LX – 1310nm, for spaces up to 10km (e.g. Cisco GLC-LX-SM-RGD).
EX – 1310nm, for spaces up to 40km.
ZX – 1550nm, for spaces up to 80km.
EZX – 1550nm, for spaces up to 120km.
BX – 1490nm/1310nm, Single Fiber Bi-Directional Gigabit SFP Transceivers, matched as “BS-U” and “BS-D” for Uplink and Downlink correspondingly, as well for spaces up to 10km. Variations of bidirectional SFPs are as well produced that employ 1550nm in one management.
1550nm 40km (XD), 80km (ZX), 120km (EX either EZX)
SFSW – Single Fiber Single Wavelength transmitters and receivers, for bi-directional SFPs are a sole fiber. Coupled with CWDM, those duple the flow thickness of fiber ties.
CWDM and DWDM transmitters and receivers at different wavelengths attaining different greatest distances.

Should We Use Third-Party Compatible SFP Transceiver?

Many customers tend to use third-party compatible Cisco SFP transceivers to save costs on these expensive modules. But there maybe a problem that the Cisco’s new line switches do not support third-party SFPs. When inserting an SFP transceiver into Cisco switches to connect network backbone, you will find it doesn’t match an official Cisco product. Then you will stumble across the following error:
%PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found in Gi1/0/0
%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port 65538 has bad crc
The Catalyst switch disables the GBIC port. That’s because Cisco Catalyst switches are configured by default not to work with non -Cisco SFPs. When a third-party SFP inserted into the port, the switch immediately recognize it doesn’t match. And it will throw the above error message and disables the port.
Except the error, Cisco tends to be very strict about the warranty requirements for the third-party components including SFP transceivers. The details are as following: When Cisco determines that a fault or defect can be traced to the use of third-party transceivers installed by a customer or reseller, then, at Cisco’s discretion, Cisco may withhold support under warranty or a Cisco support program. In the course of providing support for a Cisco networking product Cisco may require that the end user install Cisco transceivers if Cisco determines that removing third-party parts will assist Cisco in diagnosing the cause of a support issue.
That means if you use a third-party transceiver and it causes actual damage. Cisco may refuse warranty support. If the transceiver is merely suspected of being at fault, they may refuse support until you install a supported Cisco-branded transceiver.
Now you may ask “Are the third-party compatible transceivers safe?”. The answer is yes. Most third-party transceivers are made and assembled in exactly the same plants assembling officially-branded transceivers. In a matter of speaking, an official Cisco transceiver and a third-party transceiver are the same, aside from the branding. In fact, the transceivers don’t have any real way of failing that would also damage a switch. So there is no problem to use third-party compatible transceiver.
Compatible SFP transceiver modules offered by fiber-mart.com are third-party and fully compatible with major brands (Cisco, HP, NETGEAR, Finisar, Juniper, etc.) and backed by a Lifetime Warranty. fiber-mart.com have a large selection of compatible SFP modules in stock and can ship within 24 hours.


How to Install and Remove a SFP Transceiver?

SFP is short for small form-factor pluggable. It’s a compact, hot-pluggable transceiver used for telecommunication and data communications. The form factor and electrical interface are specified by a multi-source agreement (MSA). It interfaces a network device motherboard (for a switch, router, media converter or similar device) to a fiber optic or copper networking cable. SFP transceivers can support SONET, Gigabit Ethernet, Fibre Channel, and other communications standards. SFP transceivers are upgraded from the traditional version with more flexibility but a smaller size.
Sometimes you may encounter the affairs like the installation and removing of a SFP transceiver. The following will tell you how to install and remove a SFP transceiver.
Install a SFP Transceiver
The following steps tell how to install a SFP transceiver:
Attach an ESD-preventive wrist strap to your wrist and to the ESD ground connector or a bare metal surface on your chassis. SFP modules are static sensitive. Wear an ESD-preventive wrist strap so that it can prevent ESD damage.
Remove the dust cap and save for future use.
Ensure the SFP transceiver in the correct orientation for your device.
Insert the SFP module into the socket. Be sure that the SFP module is in the right position before inserting.
Observe the LED. If the LED turns green, it means the transceiver and the device establishes link successfully. While if the LED is off, there may be an installing problem with the adapter.
Remove a SFP Transceiver
To remove a SFP transceiver (see the picture), the following procedures you should bear in mind:
Attach an ESD-preventive wrist strap to your wrist and to a bare metal surface on the chassis.
Disconnect the network cable from the SFP transceiver.
Remove the SFP transceiver carefully from the module slot.
Place the removed the SFP module in a static shielding bag.
The above is about how the installation and removing of a SFP transceiver. One of the most famous brands Cisco SFP transceiver, which offers a convenient and cost effective solution in the adoptions of data center, campuses, metropolitan area, ring networks and storage networks is also suitable to these steps in applications.
At last, SFP transceivers are dust sensitive. So store the devices with plugs to avoid getting dust into the installed optical bores. And clean the optic surfaces of the fiber optical cables before the insertion. But you should better not insert or remove a SFP module until it’s necessary. Because it’s not good for keeping the useful life with repeated removals or insertions of a SFP transceiver.

What Does DOM Mean for a SFP Transceiver?

If you take a look at the description of a SFP transceiver module, you will see the “DOM support” appeared in the product details. What does it mean? In fact, DOM or Digital Optical Monitoring as the words implies, is used for monitoring some parameters of the transceiver, which can help to identify the location of the fiber link failure, simplify maintenance, improve system reliability. Obviously a SFP with DOM function is high-ender than one without it. This is why most of modern optical SFP transceivers support DOM functions. To have a further understanding of DOM, some detailed information will be introduced in the following passage.
What Is DOM Support?
As noted before, DOM is a feature allowing users to monitor parameters of the transceiver module in real-time, such as temperature, supply voltage, laser bias current as well as transmit and receive optical power. Measurement of these parameters can help network administrators to check and ensure that the module is functioning correctly. Nowadays SFP transceivers are using DOM to perform transceiver monitoring and troubleshooting operation. For example, the DOM function that Cisco GLC-SX-MMD transceiver support can assist network designers in detecting and digitizing parameter signals on circuit board in the inside of this Cisco SFP module. But how to generate DOM function for your optical transceiver?
How to Use DOM
In order to be able to take advantage of DOM capability, both the device and the platform must support the feature. When the transceiver module is DOM-enabled, a minimum software version may be required to support the feature in each platform. And there are five steps you should follow when conducting the DOM function in a SFP module.:
1. Enable example: Router> enable (Enables the privileged EXEC mode. Enter your password if prompted.)
2. Configure terminal example: Router#configure terminal (Enters the global configuration mode.)
3. Transceiver type all example: Router (config) #transceiver type all (Enters the transceiver type configuration mode.)
4. Monitoring example: Router (config-xcvr-type) #monitoring (Enables monitoring of all optical transceivers.)
5. Monitoring interval example: Router (config-xcvr-type) #monitoring interval 500 ((Optional) Specifies the time interval for monitoring optical transceivers. Valid range is 300 to 3600 seconds, and the default value is 600 seconds.)
To sum up, these three commands can used to turn on/off DOM for all transceivers type in the system:
Router (config) #transceiver type all
Router (config-xcvr-type) #monitoring
Router (config-xcvr-type) #end
Once enabled, DOM can be accessed via CLI using “show interface transceiver command”. Off all the five values, two mostly used and relevant values are TX and RX power, temperature is also used sometimes. The operating range of these three values is unique across all modules and is available in the data sheet.
Additional Information
DDM and RGD are another two common abbreviations appeared in transceiver modules’ product specifications. So, what does they refer to?
DDM, short for Digital Diagnostics Monitoring, is a technology used in SFP transceivers in order to give the end user the ability to monitor real-time parameters of the SFPs. Such parameters include optical output power, optical input power, temperature, laser bias current, and transceiver supply voltage etc.
What Is a ‘Rugged’ (RGD) Transceiver Module?
These are enhanced transceiver modules which have been designed for greater durability, and can operate under more extreme conditions. Rugged transceivers may feature enhanced ESD protection, and extended operating temperature range. Rugged transceiver modules often have “-RGD” in their product number to assist in their identification.
After going through this passage, you may have a better understanding of DOM. Before purchasing the SFP transceiver, you should read all the product details carefully because not all the transceivers can support DOM like GLC-LH-SM. Find a reliable vendor will avoid those problems. Fiberstore, as a professional telecommunication manufacturer, is aimed at providing first-class online service and high-quality products to all customers. Our SFP modules are fully compatible with Cisco, Huawei, ZTE, HP, Jumper and other brands. If you have any requirement about our products, please contact us directly.

The Solution to SFP Transceiver Module Connections

by http://www.fiber-mart.com

Recently I met a trouble that when I want interconnect WS c2960 24 TC L + 2 SFP with 1000base LH GLC LH SMD or GLC LH SM to WS C3750G 12S + 12 SFP ports, and I do not know which model of GLC LH SMD or GLC LH SM want to select, and I am going to use single mode fiber optic cable 1310m 9/125. If I need single mode SMD (2 fiber counts) or single fiber. I just want to find out WS C3750G12S + 12 SFP ports that 12 SFP ports are SM or SMD use LC connector. The solution to SFP transceiver module connections will be provided in this article.
In fact, I received several answers, someone says, the price between the 2 usually the same but GLC LH SMD SFP transceiver module supports additional option of DOM (digital optical monitoring). So he uses GLC LH SMD, as for which fiber cable, just use the single fiber cable, but I think so I use SMD how can I use single fiber cable, this is one way direction and i think i should use single mode duplex (2 fiber count). And can connect single mode duplex (2 fiber count) fiber cable to WS C3750G 12S.
Then someone from fiber-mart.com answered me that both the GLC LH SM and GLC LH SMD SFP transceiver module supports the IEEE 802.3 1000Base LX/LH standard and be good for compatible with each other. The difference between the two is the case that the GLC-LH-SMD transceiver has additional support for Digital Optical Monitoring capability. As for the second question, 1000base fx sfp, 1000base sx sfp, 1000base lx lh sfp, 1000base zx sfp, 1000base bx10 sfp, DWDM and CWDM SFP transceiver module: LC fiber connectors (single-mode or multimode fiber); 10GBASE-SR, LR, LRM, CX1 (v02 or higher) SFP+ Transceivers: LC fiber connectors (single-mode or multimode fiber).
Then if you have such similar problems, hope it can help you, and there I have a small tips for us, if you want to know where to get sfp transceiver and reach these effects, fiber-mart.com is a good place to get them, I found it do a professional site, and the price also reasonable, It is worth mentioning that fiber-mart.com is doing a big sales.