GPON vs EPON: Differences, Speeds and Which to Choose

By Madan Kc, ISP/GPON engineer at DG Link Network · Updated 5 November 2026

Quick answer: GPON and EPON are both passive optical networks that share one fibre between many customers. GPON (ITU-T G.984) gives 2.488 Gbps down and 1.244 Gbps up per PON port and usually splits to 64 customers. EPON (IEEE 802.3ah) gives 1.25 Gbps both ways and usually splits to 32. For a new network, choose GPON unless you already own EPON gear or your market sells only EPON equipment. The two cannot be mixed on the same PON port.

What GPON and EPON have in common

Both are PON (passive optical network) technologies. One fibre leaves the OLT in your exchange, passes through passive splitters that need no power, and reaches many customers. Each customer has an ONU or ONT. Both use the same light wavelengths: about 1490 nm downstream and 1310 nm upstream. If you want the full picture of how this reaches a home, read how an ISP network works from OLT to home.

GPON vs EPON side by side

GPON and EPON compared (typical figures)
Item	GPON	EPON
Standard	ITU-T G.984	IEEE 802.3ah (1000BASE-PX)
Downstream line rate	2.488 Gbps	1.25 Gbps
Upstream line rate	1.244 Gbps	1.25 Gbps
Usable throughput	About 2.4 Gbps down / 1.2 Gbps up	About 1 Gbps each way (8b/10b coding overhead)
Typical split ratio	1:64 (up to 1:128 in the standard)	1:32 (1:64 possible with the right optics)
Reach	Up to 20 km	10 km (PX10) or 20 km (PX20)
Framing	GEM encapsulation of Ethernet, voice and TDM	Native Ethernet frames
ONU authentication	Serial number (and optional password)	MAC address
Next upgrade	XG-PON / XGS-PON (10G)	10G-EPON

Figures are the standard values. Real speed also depends on your OLT, optics, split ratio and how many customers share a port.

How they differ in practice

Bandwidth per customer

GPON has more downstream capacity per port and supports a larger split, so each customer gets more headroom at a similar cost per port. EPON’s 1.25 Gbps is shared by up to 32 customers, which is fine for ordinary plans but tighter when many people stream at the same time.

Simplicity

EPON is plain Ethernet, so it is easy to understand and cheap to build. GPON adds its own framing layer (GEM) and service profiles, which is a little more to learn but gives better control of quality of service, VLANs and voice.

Provisioning

On GPON you register each ONT by serial number and attach line and service profiles. On EPON you register by MAC address. Both are done on the OLT: see the Huawei OLT complete setup guide for GPON and the BDCOM OLT complete setup guide for a common EPON platform.

Splitters and power budget

A 1:64 split loses more light than a 1:32 split, so check your budget before you promise a split ratio. Use the fiber splitter calculator to estimate loss per branch.

Compatibility

A GPON ONT will not register on an EPON OLT, and the reverse. Some vendors sell combo ONUs that can run in either mode, but the OLT port itself is one or the other. Mixing vendors on the same OLT can also fail, so test one unit before you buy a batch.

Which one should you choose?

Choosing between GPON and EPON
Your situation	Pick
New network, plans of 100 Mbps or more	GPON
You want a clear path to 10G	GPON, then XGS-PON
You already run EPON OLTs and ONUs	Stay on EPON; add combo ONUs where you can
Very tight budget and low-speed plans	EPON can be cheaper, but check ONU availability
You need voice and business services	GPON

My advice for a new ISP is GPON. It is the more common choice for new FTTH builds, the ONT range is wide, and you will find more spares and guides.

How to tell which one you have

Check the label on the ONT: it says GPON, EPON or XPON (combo).
On the OLT, GPON ports are shown as gpon interfaces and EPON ports as epon interfaces.
An ONT that never registers and shows a steady PON light but no link may be the wrong type, or the fibre may be at fault. See ONT red LOS light: what it means and how to fix it.

Troubleshooting ONUs? Start with Huawei OLT ONU offline / LOS troubleshooting or BDCOM ONU offline / LOS troubleshooting.

FAQ

Is GPON faster than EPON?

Yes on the downstream: 2.488 Gbps against 1.25 Gbps per PON port. Upstream is close, 1.244 Gbps against 1.25 Gbps.

Can I use a GPON ONT on an EPON OLT?

No. The protocols differ, so the ONT will not register. A combo (XPON) ONU can switch between the two.

What is the split ratio of GPON and EPON?

GPON is usually 1:64 and EPON usually 1:32. Your optical power budget decides what is safe on a real network.

Which is cheaper, GPON or EPON?

EPON equipment is often a little cheaper, but GPON’s larger split and wider ONT choice usually make it the better value for new builds.

Is there anything faster than GPON?

Yes. XG-PON and XGS-PON give 10 Gbps, and 10G-EPON is the EPON equivalent.

Sources: ITU-T G.984 (GPON) and IEEE 802.3ah (EPON) standards, plus my own experience running both on ISP networks. Figures are typical; check your vendor’s datasheet.