Buying an OLT does not mean you have to buy a rack unit. A village committee building, one hotel floor, a single block in a campus, or a small remote branch office might serve only a few dozen to a couple hundred users. Hauling in a high-capacity central office just eats rack space and budget. For those cases a 1-port or 2-port fiber OLT is the right answer: it compresses the PON ports, uplink, and remote management a central office needs into a small box that lights up ONUs the moment you connect fiber.
Below, we use the real specs of Rayin's L101P (1-port) and L102P (2-port) mini OLT to show, in one pass, what a 1-port or 2-port ultra-small central office actually measures, how many users it carries, and where it differs from the big iron.
A home optical modem is a user-side terminal that serves one subscriber. A large OLT is a multi-slot central office in a server room carrying thousands of users. A 1-port or 2-port OLT sits in the middle tier: it has the full central-office feature set — downstream PON, upstream aggregation, remote management — but with physical size and port count pressed to the minimum.
Not every "small" box is the same. Using Rayin's own L101P (1-port) and L102P (2-port) specs, here is where 1-port and 2-port actually diverge.
Rayin built the L101P and L102P into the same 239 × 132 × 44 mm 1U chassis, both at ≤2 kg; the only difference is the number of PON ports — the 1-port drives 128 subscribers, the 2-port drives 256. Rather than shrinking the 1-port and stretching the 2-port, keeping one 1U slim-box size makes deployment uniform: the same footprint in a wiring closet, a stairwell, or a cabinet. Domestic OLT vendors have matured these 1-port and 2-port small models over the last few years, and the price sits well below imported gear.
Dimension | Home optical modem | 1/2-port OLT (ultra-small central office) | 4/8/16-port 1U OLT | Large-capacity rack |
Positioning | User-side terminal | Very-low-density central office | Mid-density central office | Core central office |
PON ports | 1 (upstream) | 1–2 (downstream) | 4–16 (downstream) | Dozens to hundreds |
Form factor | Desktop box | Desktop / wall-mount / small rack | 19-inch 1U | Multi-U blade |
ONUs served | — | 128–256 | 512–2048 | Thousands+ |
Power redundancy | None | Optional dual power | Common 1+1 | Always |
Typical scene | Home | Village single building / hotel floor / branch | Campus / aggregation | Metro core |
GPON runs up to 1:128 per port; EPON commonly 1:64. So the ceiling for a 1-port or 2-port OLT is clear:
1-port GPON → 128 ONUs
2-port GPON → 256 ONUs
2-port EPON → 128 ONUs
Those are theoretical maximums. In real deployment, leave about 20% headroom — if you plan for 80 subscribers, don't fill the port to its 128; keep some for later expansion and for optical-power fluctuation. A 1-port or 2-port small OLT carrying one to two hundred users is the most common configuration in village-connectivity, hotel, and branch scenarios.
Split ratio: the market offers both 1:128 and 1:64 access ratios; pick based on your actual situation.
ONU compatibility: an OLT often has to mix ONUs from different brands. Insist on standard OMCI / OAM; don't buy into a private protocol that locks you in, or you'll be held hostage when swapping terminals later.
Uplink bandwidth: 1-port GPON delivers 2.5 G down / 1.25 G up. If the uplink port isn't 10G, bandwidth jams. Rayin's L101P / L102P give 1 × SFP+ 10GE uplink, which is far roomier; a 2-port model aggregating two PON uplinks needs an even larger uplink.
Temperature range: wall-mounted in an air-conditioned-less wiring closet, summer can top 50°C. A unit rated -20~60°C shrugs off a normal closet; a model with a narrower range needs guaranteed ventilation.
Village connect / single building: one village committee building with dozens to a hundred surrounding households — a 1-port OLT wall-mounted saves the server room, and Rayin's L101P class is the typical fit for an OLT FTTH rollout.
Hotel floor / single building: one floor or one building with a few hundred rooms — a 2-port OLT splits the two PONs across different floors, easy to expand and isolate.
Single-split monitoring backhaul: a front-end of one to two hundred IP cameras aggregated to one split point; a small OLT downstream to ONUs hauls video back, simpler than pulling cable to every point.
Remote small site / temporary node: no air conditioning, no dedicated ops.
Rayin's 1-port OLT approach follows this same very-low-density thinking; for specific models and port combinations, ask the vendor for a datasheet to compare.
Model | PON ports | Form / size | Power | Operating temp | Split ratio | Notes |
Rayin L101P | 1 × GPON (SFP) | 239×132×44 mm, ≤2 kg, 1U rack / desktop | AC 100–240V, DC 12V/2A | -20~60°C | 1:128 | 2×GE + 1×SFP+ 10GE uplink, 128 ONU, metal casing |
Rayin L102P | 2 × GPON (SFP) | 239×132×44 mm, ≤2 kg, 1U rack / desktop | AC 100–240V, DC 12V/2A | -20~60°C | 1:128 | 2×GE + 1×SFP+ 10GE uplink, 256 ONU, metal casing |
1、How do I choose between 1-port and 2-port OLT?
A single split point with users in one building is fine on a 1-port OLT. If you want two PONs in one box (different floors / different buildings), or a little redundancy on a key node, go 2-port. The price gap is small; the difference is mainly whether you can split.
2、How many households can a 1-port OLT serve?
Rated 1:128, meaning 128 ONUs. In practice, plan around 100 with headroom for stability.
3、EPON or GPON for 1-port / 2-port?
New build wanting higher bandwidth and 1:128 density → GPON. Expanding a legacy EPON network on a cost-sensitive basis → EPON; a 2-port EPON model is the EPON path.
4、Can a 2-port OLT act as redundancy?
Strictly, the two PON ports are independent splits, not hot-standby failover. But they spread users across two links, so one link failure hits only half. For true zero interruption, you need PRP/HSR or the big iron.
5、Will wall-mount without AC break it?
Check the operating temperature. A -20~60°C unit handles a normal closet; a narrower-range model needs shaft ventilation or it trips high-temp protection in summer.
6、What if power drops?
Pick a model with dual power. Rayin's L101P / L102P both support DC input.
A 1-port or 2-port model is not a "shrunken big device" — it is a compact central office redesigned for very-low-density scenes: ports pressed to 1–2, size to palm-sized, budget down too, yet the PON, uplink, and management you expect are all there. Match PON type, port count, split ratio, uplink, power, and temperature, and you basically can't go wrong.
For more on small OLT products, visit Rayin's website at www.szrayin.com.
Customer Manager at Shenzhen Rayin Technology Co., Ltd.
