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Transceivers (SFP)

Network transceivers are Small Form-factor Pluggable (SFP) devices that convert electrical signal into a transmission across a network link. These hot-swappable modules plug into a network switch, router or server port, to convert these signals. That makes them incredibly important for enterprise IT businesses.

At ITinStock, we stock a range of high-quality new and refurbished transceivers covering all major form factors and speeds, including SFP (1GbE), SFP+ (10GbE), SFP28 (25GbE), QSFP+ (40GbE), QSFP28 (100GbE), and XFP (10GbE), as well as Direct Attach Copper (DAC) and Active Optical Cable (AOC) assemblies. We stock transceivers from Cisco, HPE, Dell, Juniper, Arista, and more.
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Benefits of Network Transceivers

Network transceivers are pluggable, meaning they give you the flexibility for different media types used for every link in your network. For example, a single switch can have its ports populated with short-reach multimode SFP+ modules for intra-rack connections, long-reach single-mode SFP+ modules for cross-building fibre links, and QSFP+ modules for high-bandwidth uplinks to the aggregation layer, all at the same time. Because transceivers are hot-swappable, they can be changed without powering down the switch or causing any disruption to other active ports.

When it comes to short-distance connections in a rack, Direct Attach Copper (DAC) cables and Active Optical Cables (AOCs) offer a cost-effective solution. DAC cables can cover distances up to around 7 metres at a lower cost and power draw than optical transceivers, whereas AOCs use active optical fibre with integrated connectors that extend this to around 100 metres. Both are widely used for server-to-switch and switch-to-switch connections within a data centre.

Why Choose Refurbished Transceivers from ITinStock?

At ITinStock, we are happy to discuss any bespoke configurations for your transceiver requirements, whether that's a specific form factor, speed, reach, fibre type, or vendor compatibility. Each of our refurbished transceivers undergoes rigorous testing, in which optical performance, EEPROM data integrity, and link-up behaviour are verified to ensure the module performs to specification. We can deliver quickly to the UK and worldwide using our courier partners. Our expert support team is on hand to help with any pre-sales questions and compatibility queries you may have.

Complement Your Transceiver Setup

Maximise your networking investment with these complementary IT components:

  • Networking Switches We stock refurbished switches from Cisco, Dell, HPE, Juniper, Arista, Extreme Networks, and more. Why not pair your switch with the right optics?
  • Network Modules We have a vast range of line cards and expansion modules for modular switch and router chassis. Browse our Network Modules for more.
  • Rack Servers Many of our servers have optional network cards including SFP+ or QSFP+ ports that require transceivers for fibre uplinks. Check out our full range of refurbished servers for more.

Frequently Asked Questions

What is an SFP, and what transceiver form factors do you stock?
SFP stands for Small Form-factor Pluggable. It is a compact, hot-swappable transceiver module that plugs into a dedicated port on a switch, router, or server NIC to provide a single network link over fibre or copper. The SFP family has evolved through several generations, each offering higher speeds in the same or similar physical footprint. We stock all major form factors: SFP (up to 1GbE), SFP+ (10GbE), SFP28 (25GbE), QSFP+ (40GbE), QSFP28 (100GbE), and XFP (10GbE, an older form factor larger than SFP+ still found in legacy equipment). We also stock Direct Attach Copper (DAC) and Active Optical Cable (AOC) assemblies in SFP+, QSFP+, and QSFP28 form factors for short-distance rack and row connections. If you need a specific form factor, speed, or reach not currently listed, contact our team and we will check availability.

What is the difference between SFP, SFP+, SFP28, and QSFP28, and which do I need?
The key difference between these form factors is speed. SFP supports up to 1GbE and is used in older switches and for lower-speed uplinks. SFP+ supports up to 10GbE and remains one of the most widely used transceiver types in enterprise networks. SFP28 supports 25GbE and uses the same physical footprint as SFP+, making it the natural upgrade path from 10G to 25G access without changing switch hardware. QSFP+ supports 40GbE using four 10G lanes in a single, slightly larger module, commonly used for switch-to-switch uplinks and spine connections. QSFP28 supports 100GbE using four 25G lanes and is now the standard choice for high-speed data centre uplinks and spine-leaf interconnects. As a general guide: for connecting access switches to servers, SFP+ or SFP28 are typical; for inter-switch uplinks and spine connections, QSFP+ or QSFP28 are the right choice. If you are unsure which form factor your equipment requires, check the port labelling on your switch or contact our team.

What is the difference between single-mode and multimode transceivers?
Single-mode and multimode refer to the type of fibre optic cable the transceiver is designed to work with, and they are not interchangeable. Multimode fibre has a larger core diameter and is used for shorter distances, typically up to 300 metres for 10GbE (OM3 fibre) or 400 metres (OM4 fibre). Multimode transceivers use a lower-cost VCSEL light source and are the standard choice for connections within a building or data centre. Single-mode fibre has a much smaller core diameter and supports much longer transmission distances, from 10 km for standard LR (Long Range) modules up to 40 km or 80 km for extended-reach ER and ZR modules. Single-mode transceivers use a laser light source and are more expensive than multimode equivalents, but they are the only practical option for connecting buildings, campuses, or sites over long distances. If you are connecting devices within the same rack or data centre room, multimode SFP+ (SR) modules are usually the right choice. If you are connecting across a campus or between buildings, single-mode (LR) modules are required.

Do transceivers need to be the same brand as my switch?
Not necessarily, but it is an important consideration. Most major switch vendors, including Cisco, Juniper, HPE, and Dell, code their switches to check the EEPROM data on inserted transceivers and may generate error messages, log warnings, or in some cases refuse to activate a port if a non-vendor-coded module is detected. Cisco switches, for example, display an 'unsupported transceiver' warning when a non-Cisco-coded module is inserted, though in most cases the port will still operate. Some vendors allow third-party transceivers to be used without restriction. For complete compatibility and to avoid any risk of warning messages or port behaviour differences, we recommend using vendor-branded transceivers that match your switch platform where possible. Our stock includes vendor-branded transceivers from Cisco, HPE, Dell, Juniper, Arista, and others, allowing you to match the transceiver brand to your switch. If you are unsure what is compatible with your specific switch model, our team at ITinStock can advise before you order.

Does ITinStock offer warranty on refurbished IT equipment?
Yes. All our refurbished IT equipment - servers, storage, networking and components, are thoroughly inspected and tested before dispatch to make sure they function as intended. In the event that any equipment develops a fault or arrives damaged through no fault of the customer, we offer a 3-year warranty on all refurbished equipment covering repair or replacement. Please speak with our account managers and customer service team for full warranty terms and conditions.

Find Your Ideal Transceiver Today

Browse our complete range of refurbished transceivers or contact our team for expert advice on selecting the right optic for your switch, router, or server.

Phone: +44 (0)20 4631 3555
Email: hello@itinstock.com

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