Description
A 1000BASE-SX transceiver is a plug-in SFP module that turns an empty fiber port into a 1 Gbps link over multimode fiber. This listing is Sophos part ITFZTCHSX, for the SFP ports on Sophos XGS firewalls and FleXi Port modules.
Before you order: Sophos sells SFP transceivers separately from XGS firewalls, so the SFP ports are empty out of the box. You need one transceiver at each end of the link. Use 1000BASE-SX at both ends, on multimode fiber. SX and LX are both 1 Gbps, but mixing them on one link is outside the standard.
Specifications
| Sophos part number | ITFZTCHSX |
|---|---|
| Interface standard | IEEE 802.3 1000BASE-SX |
| Form factor | SFP |
| Data rate | 1 Gbps |
| Media | Multimode fiber |
| Wavelength | 850 nm nominal (IEEE range 770 to 860 nm) |
| Connector | Duplex LC |
| Reach in the standard | Up to 550 m on 50 µm multimode (OM2 or better); 220 to 275 m on older 62.5 µm fiber (275 m on OM1) |
| Listed range for this Sophos part | 550 m (as listed by Avanet) |
| Sophos requirement for XGS rack-model fiber ports (XGS 2100 and up) | UL-approved Laser Class I transceivers rated 3.3 V DC, 1 W maximum (Sophos) |
| How it is sold | One-time hardware purchase, not a subscription |
Wavelength, media and reach for 1000BASE-SX come from the IEEE 802.3 standard (IEEE 802.3 summary). We could not find a public Sophos datasheet for this part number; Sophos keeps its compatibility list in KBA-000005164 on the Sophos support site.
Which Sophos ports it fits
| Sophos appliance or module | Port |
|---|---|
| XGS 108(w) | 1 x SFP, 1 Gbps (Sophos) |
| XGS 118(w), XGS 128(w) | 1 x SFP, 1 Gbps (Sophos) |
| XGS 138 | 2 x SFP+, listed at 1/10 Gbps; ask us to confirm a 1 Gbps part for this port (Sophos) |
| XGS 2100, XGS 2300 | Ports F1 and F2, SFP (Sophos) |
| XGS 3100, XGS 3300 | Ports F3 and F4, SFP (F1 and F2 are SFP+, listed at 1/10 Gbps; ask us before using a 1 Gbps part there) (Sophos) |
| FleXi Port modules | 8 port GbE SFP; 2 port GbE bypass + 4 port GbE SFP (Sophos) |
The XGS 88 has no SFP port. Sophos rates FleXi Port module SFP+ ports for 1 Gbps only with transceivers that support both 1 and 10 Gbps, so this 1 Gbps part belongs in an SFP port. On XGS 2100 to 3300 FleXi Port modules, Sophos requires the same speed configuration on every SFP+ port of the module (Sophos operating instructions, Sophos help).
Sophos Switch models also take SFP or SFP+ transceivers bought separately (Sophos). Send us the switch model and we confirm the right part before you order.
How to use it
- Check the port. Sophos lists its SFP ports at 1 Gbps. It lists the SFP+ ports on the XGS 138, XGS 3100/3300 (F1 and F2) and XGS 5500/6500 at 1/10 Gbps, the XGS 4300/4500 SFP+ ports as 10 GE, and FleXi Port module SFP+ ports as dual-rate when the transceiver supports both rates. The table above lists the Sophos ports.
- Match the far end. The device at the other end needs a 1000BASE-SX optic on multimode fiber. Use the same standard at both ends; mixing optic types is outside the standard and is not supported.
- Use the right cable. Connect a multimode duplex LC patch cord (50 µm OM2, OM3 or OM4 for the full 550 m).
- Insert the transceiver. Sophos: push the module carefully into the port until it engages, and the interface is ready for use straight away. To remove it, unplug the cable first, then pull the module out (Sophos instructions).
- Set the port in Sophos Firewall. Go to Network > Interfaces, edit the port, and open Advanced settings > Port settings. Set speed, duplex and auto-negotiation to match the device at the other end; Sophos warns that a speed mismatch with a third-party router or switch can cause errors, disconnections or slow performance (Sophos help).
- Plan uplinks to save ports. Putting the ISP handoff or the switch-to-firewall uplink on an SFP or SFP+ port keeps a copper port free on the firewall, and on the switch too if it also uses an SFP port for the link. Our firewall sizer shows which XGS models have the ports you need.
Compare Sophos transceivers
The ten Sophos transceivers in our store, side by side. Reach figures are the IEEE 802.3 values for each standard; the highlighted row is this product.
Swipe sideways to see every column.
| Transceiver | Part number | Port | Speed | Media and wavelength | Reach | Best for |
|---|---|---|---|---|---|---|
| 1GbE copper | ITFZTCHTC | SFP | 1 Gbps | Copper, RJ45 | 100 m (copper) | Turning a spare SFP port into an extra copper port, or a short copper uplink to a switch |
| 1GbE copper | HA1BCT00ZZPCAA | SFP | 1 Gbps | Copper, RJ45 | 100 m (copper) | Turning a spare SFP port into an extra copper port, or a short copper uplink to a switch |
| 1GbE fiber, short range | ITFZTCHSX | SFP | 1 Gbps | Multimode fiber, 850 nm, LC | 550 m (multimode) | Fiber runs inside a building, such as a switch closet to the server room |
| 1GbE fiber, short range | HA1BSF00ZZPCAA | SFP | 1 Gbps | Multimode fiber, 850 nm, LC | 550 m (multimode) | Fiber runs inside a building, such as a switch closet to the server room |
| 1GbE fiber, long range | ITFZTCHLX | SFP | 1 Gbps | Single-mode fiber, 1310 nm, LC | 5 km (single-mode) | Links between buildings, and ISP or carrier fiber handoffs that use single-mode |
| 1GbE fiber, long range | HA1BLF00ZZPCAA | SFP | 1 Gbps | Single-mode fiber, 1310 nm, LC | 5 km (single-mode) | Links between buildings, and ISP or carrier fiber handoffs that use single-mode |
| 10GbE fiber, short range (dual rate) | ITFZTCHXF | SFP+ | 10 Gbps | Multimode fiber, 850 nm, LC | 300 m OM3, 400 m OM4 | 10 Gbps links inside a building, such as firewall to core switch or server rack |
| 10GbE fiber, short range (dual rate) | HAGBSF00ZZPCAA | SFP+ | 10 Gbps | Multimode fiber, 850 nm, LC | 300 m OM3, 400 m OM4 | 10 Gbps links inside a building, such as firewall to core switch or server rack |
| 10GbE fiber, long range (dual rate) | ITFZTCHLR | SFP+ | 10 Gbps | Single-mode fiber, 1310 nm, LC | 10 km (single-mode) | 10 Gbps links between buildings, and 10 Gbps ISP handoffs on single-mode |
| 10GbE fiber, long range (dual rate) | HAGBLF00ZZPCAA | SFP+ | 10 Gbps | Single-mode fiber, 1310 nm, LC | 10 km (single-mode) | 10 Gbps links between buildings, and 10 Gbps ISP handoffs on single-mode |
Which one do you need?
- Under 100 m, copper cable already in place: 1GbE copper (1000BASE-T).
- Inside one building on multimode fiber: 1000BASE-SX at 1 Gbps, or 10GBASE-SR at 10 Gbps.
- Between buildings, or an ISP handoff on single-mode fiber: 1000BASE-LX at 1 Gbps, or 10GBASE-LR at 10 Gbps.
Before you order
- One transceiver per link end. A firewall connected to a switch over fiber needs two: one for each device.
- Fiber patch cords and the device at the far end are separate. Tell us the far-end make and model and we check the optic type.
- Rack models can add SFP ports with an 8 port GbE SFP FleXi Port module.
We also list Sophos part HA1BSF00ZZPCAA, sold under the same standard name (1000BASE-SX). Sophos does not publish a cross-reference between the two part numbers. If a quote, tender or existing order names a part number, order that one; if not, ask us which is in stock.
Frequently asked questions
Which Sophos firewalls does the ITFZTCHSX fit?
It fits Sophos SFP ports: the single SFP port on the XGS 108, 118 and 128, ports F1 and F2 on the XGS 2100 and 2300, ports F3 and F4 on the XGS 3100 and 3300, and the SFP ports on GbE FleXi Port modules. Sophos lists the XGS 138 SFP+ ports at 1/10 Gbps but does not say which 1 Gbps transceivers it supports there, so ask us before ordering for an XGS 138. The XGS 88 has no SFP port.
How far can a 1000BASE-SX transceiver reach?
The IEEE 1000BASE-SX standard specifies up to 550 m on 50 micrometer multimode fiber and 220 to 275 m on older 62.5 micrometer fiber.
Do I need a transceiver at both ends of the link?
Yes. Each end of a fiber link needs its own transceiver, and both should use the same standard. One transceiver goes in the Sophos port; the switch, router or ISP device at the far end needs a matching one.
What is the difference between 1000BASE-SX and 1000BASE-LX?
Both run at 1 Gbps. 1000BASE-SX uses 850 nm light on multimode fiber for runs up to about 550 m, usually inside a building. 1000BASE-LX uses 1310 nm light on single-mode fiber for runs up to 5 km in the standard, such as between buildings. The two cannot be mixed on one link.
Will a third-party transceiver work in a Sophos firewall?
Sophos keeps a list of its own and tested third-party transceivers in knowledge base article KBA-000005164. Sophos staff have said that other third-party transceivers with similar coding might work but have not been tested, so they are not recommended. For a supported setup, use a Sophos part.
Is a Sophos transceiver a subscription?
No. It is a one-time hardware purchase. There is no term or renewal on the transceiver itself.
All Sophos XGS add-on modules and transceivers · Sophos XGS firewalls · Compare XGS models · Glossary
Get the right optic, first time
Send us the firewall or switch model, the far-end device and the cable you have. A Nuformat specialist confirms the part and quotes in CAD or USD, usually within two to three business days.
Request a quotePort, installation and configuration details from Sophos documentation; reach and wavelength from the IEEE 802.3 standard. Sources: Sophos, Operating Instructions XGS 88(w)/108(w); Sophos, Operating Instructions XGS 118(w)/128(w)/138; Sophos, Operating Instructions XGS 2100/2300/3100/3300; Sophos, Operating Instructions XGS 5500/6500; Sophos, XGS 1U firewalls product page; Sophos Firewall help, Edit physical interface (port settings); Sophos, Operating Instructions Sophos Switch series; Sophos KBA-000005164, Sophos and third-party transceivers/SFPs compatibility list; Sophos Community, SFP compatibility (Sophos staff reply); IEEE 802.3 Gigabit Ethernet media summary (Wikipedia); Avanet, Sophos 1000Base-SX fiber transceiver listing. Checked October 5, 2026. Pricing and availability confirmed by Nuformat at the time of quotation.