Relationship of ONT and OLT in GPON Network
Gigabit passive optical network (GPON) is a point-to-multipoint access mechanism providing end-users with the ability to consolidate multiple services onto a single fiber transport network. To realize this technology, many devices are used to support the network, such as optical splitter, ONT, OLT, etc. In this article, we will mainly discuss the functions of ONT and OLT in the GPON network.
Gigabyte Passive Optical Network, known as GPON, relies on fiber optic cables to deliver video, data, and voice signals. GPON networks are currently the leading form of Passive Optical Networks (PONs), and offer up to a 1:64 ratio on a single optical fiber, meaning, a single fiber from the OLT can deliver video, data, and voice signals to up to 64 end users (or residences).
What are OLT and ONT?
An optical network terminal (ONT) is an optical modem that connects to the termination point with an optical cable. It is used at the end user’s premise to connect to the PON network on one side and interface with the user on the other side. Data received from the customer end is sent, aggregated, and optimized by the ONT to the upstream OLT. ONT is also known as an optical network unit (ONU). ONT is an ITU-T term, while ONU is an IEEE term. They both refer to the user-side equipment in the GPON network. A small difference between them might be the application locations. ONU can work in different temperatures and weather conditions.
An optical line terminal (OLT) is the endpoint hardware equipment located in a central office of the PON network. Its basic function is to control the float information in the optical distribution network (ODN) to go in both directions. OLT converts the standard signals used by fiber optic service (FiOS) to the frequency and framing used by the PON system. In addition, it coordinates the multiplexing between the ONT conversion devices. There are two float directions for the OLT system. One is the upstream direction to distribute different types of data and voice traffic from users. The other is the downstream direction which gets data, voice, and video traffic from the metro network or a long-haul network and sends it to all ONT modules on the ODN.
Typical GPON Network with and without WiFi:
Compared to the standard copper wire in most distribution networks, GPON networks are 95% more energy efficient – they use economical light signalization over fiber optic cable, as opposed to electrical signals over copper and coaxial cable. In addition to efficiency, Gigabyte Passive Optical Networks provide a low-cost solution to adding new users by using optical splitters, which makes it easy to add and manage new customers, making GPON networks very desirable in populated areas.
The following image shows how the GPON OLT device deployed in a typical GPON network delivers services to end users by way of a GPON ONT installed inside the house:
A typical GPON network is pretty straightforward. It consists of an OLT (Optical Line Terminal), ONT (Optical Network Terminal, and sometimes called an ONU, Optical Network Unit), and an optical splitter. Signals from the central office OLT transmit to the splitter, then the splitter spreads the signal to the GPON ONT which resides inside the home of the end-user. From the ONT, the end-user can connect all of their video, data, and voice, data, and voice devices like computers, televisions, and VoIP phones.
How to Add or Delete ONT on OLT?
Way to Add ONT on OLT
If the password of an ONT is obtained, you can run the ONT add command to add the ONT offline. However, if the password is unknown, you can run the port ported on-auto-find command in the GPON mode to enable the ONT auto-find function of the GPON port, and then run the ONT confirm command to confirm the ONT. When the ONT is added, you need to run the display ONT info command to see the current status of ONT. If the control flag is active,
Way to Delete ONT on OLT
When you need to delete the ONT on OLT, please use the delete command. Then ONT configuration data is deleted with the deletion of the ONT and the online ONT is forced offline. ONT can’t be deleted when it has been configured with other services. You need to unbind the service first before deleting the ONT.
How to Troubleshoot ONT?
To troubleshoot the ONT, you should remember that the most important step is to connect your computer directly to the ONT to see if the problem goes away. You can use the Ethernet cable for connection. If the problem still exists, you can reconnect the ONT power supply to clear its internal cache. If the network can not be restored after the above methods, maybe you need to consult professionals for help.
ONT and OLT are indispensable components in the GPON network system. If you are considering purchasing the ONT or OLT devices, FS.COM is a good place to go. Different types of ONT and OLT equipment are provided with high integration, flexible adaption, and great reliability to meet all your requirements.