GLC-T vs GLC-TE: 1000BASE-T Copper SFP Differences and Replacement

The only meaningful difference between the Cisco GLC-T and GLC-TE is the operating temperature range. The GLC-T is a commercial-temperature module (0 to 70 degrees C / 32 to 158 degrees F); the GLC-TE is an extended-temperature module (-5 to 85 degrees C / 23 to 185 degrees F). Both are 1000BASE-T copper SFP transceivers with an RJ-45 connector that run Gigabit Ethernet up to 100 m over Category 5/5e cabling. Electrically and mechanically they are identical and interchangeable in the same port. The GLC-T has been announced End-of-Sale by Cisco, and the GLC-TE is Cisco's named replacement, so for any purchase today you should buy the GLC-TE. It drops straight into the same supported switches and routers with no configuration change.

The short answer: temperature range and lifecycle

If you only remember one thing, remember this: the GLC-T and GLC-TE are the same 1000BASE-T copper SFP, and the single spec that separates them is operating temperature. The GLC-T is rated for a commercial range of 0 to 70 degrees C. The GLC-TE is rated for an extended range of -5 to 85 degrees C. Everything else a buyer cares about is identical: both are Small Form-Factor Pluggable (SFP) modules with an RJ-45 jack, both deliver Gigabit Ethernet over copper, both reach 100 m on Category 5/5e or better, and both support auto-negotiation and Auto-MDI/MDIX.

The practical reason this comparison comes up at all is lifecycle. Cisco announced the GLC-T as End-of-Sale, and it named the GLC-TE as the replacement part. The GLC-TE carries the wider temperature window and currently has no published end-of-life milestone, which is exactly why Cisco consolidated onto it. So the modern, orderable, drop-in part is the GLC-TE. If you are quoting new hardware, you are quoting GLC-TE.

GLC-T vs GLC-TE spec comparison

Side by side, the modules are nearly indistinguishable on paper apart from the temperature rating and where each one sits in its lifecycle. The table below is the at-a-glance version buyers actually use when reconciling an old bill of materials against what they can order today.

Note the row that matters most operationally: temperature. A GLC-T sitting in a climate-controlled wiring closet will run for years; the same module in an unconditioned outdoor cabinet, a factory floor, or a transit enclosure is the one that fails on the first cold morning. That is the gap the GLC-TE closes, and it is why Cisco felt comfortable retiring the GLC-T behind a single extended-temperature SKU.

Is the GLC-TE a true drop-in replacement?

Yes. The GLC-TE is mechanically and electrically a one-for-one swap for the GLC-T. Same SFP form factor, same RJ-45 copper interface, same 1000BASE-T behavior, same 100 m reach. You pull the old GLC-T, slide in the GLC-TE in the same cage, and the link comes up with no configuration change required on a platform that already accepted the GLC-T.

This is the cleanest kind of refresh: there is no IOS-XE or NX-OS command to re-enter, no interface re-profiling, and no media-type juggling. If your running config referenced the port by interface (not by a transceiver-specific OID or hardcoded media assumption), the GLC-TE simply inherits the same port role. The only thing changing is the part number on the next purchase order and the temperature headroom in the closet or cabinet.

Supported platforms and the 10/100 caveat

Both modules are designed for Cisco switches and routers that take standard SFP ports across the Catalyst switching line, Nexus data-center switches, and ASR/ISR routers with SFP-capable interfaces. Because the GLC-TE is the sanctioned replacement, anywhere a port previously accepted a GLC-T it will accept a GLC-TE. The authoritative way to confirm fit for a specific chassis and software train is the platform's transceiver compatibility matrix, but for the legacy-to-replacement swap the rule of thumb holds: GLC-T port equals GLC-TE port.

One caveat trips up buyers who expect a copper SFP to behave like a fixed RJ-45 switch port. On most Catalyst and Nexus platforms, a 1000BASE-T copper SFP like the GLC-T/GLC-TE negotiates at 1000 Mbps only in the SFP cage. The 10/100/1000 auto-negotiation marketing language describes the PHY's capability, but many Cisco switch platforms do not pass 10 or 100 Mbps through these copper SFPs. If you need a 10 or 100 Mbps copper handoff, do not assume the SFP delivers it. Plan for gigabit, and validate against the specific platform's documentation before you commit a design that depends on lower speeds. For environments mixing media types and speeds, it is worth getting the full optics and transceiver list right up front; you can browse current Cisco copper and fiber SFP options in our optics and transceivers catalog.

Which one to buy today

For any new order, buy the GLC-TE. It is the active part, it carries the wider -5 to 85 degrees C temperature window, and it drops into every port that took a GLC-T. There is no scenario in a new purchase where the commercial-only GLC-T is the better pick over the GLC-TE; the GLC-TE is a strict superset on temperature at parity on everything else.

The GLC-T still appears in three situations: legacy bills of materials written before the End-of-Sale, used and refurbished inventory, and spares pools that were stocked years ago. If you are maintaining an existing fleet, those GLC-T units are fine to keep running inside their commercial temperature limits; you do not need to rip them out. But when one fails or you expand, the replacement is the GLC-TE. If your deployment is genuinely harsh, outdoor, or industrial, also evaluate the industrial-temperature copper SFP variant (rated to -40 degrees C) rather than stretching the GLC-TE past its extended rating.

Reconciling an old parts list, standardizing a spares kit, or sizing a refresh across many closets is exactly where a partner saves you a re-order. Browse current copper SFP stock in our optics and transceivers catalog, or if a switching refresh is driving the optics decision, start from the Cisco switches catalog. When you are ready for pricing and TAA-compliant sourcing, request a quote and we will map your legacy GLC-T lines to current GLC-TE part numbers.