Hello,
everyone!
Today, I will continue to write about ONU service interfaces. In these articles about ONU service interfaces, I write about interfaces such as ethernet ports, WiFi, POTS and RF. Today's topic is POTS and RF ports.
POTS is an abbreviation from Plain Old Telephone Service. These ports are used for telephones. ONT can have one or two POTS ports. Figure 1. shows us interfaces on the Huawei ONT HG8247H.

Figure 1. ONT HG8247H
POTS interfaces are like small ethernet interfaces. Telephone cables are used to connect the telephone and the ONT. It has four wires – red, green, yellow and black. The telephone cable connectors are called RJ-11. We can see that connector in the following picture (figure 2.). RJ-11 has 6 pins. There is no standard, the RJ-11 uses 2 wires (1 pair) in the middle. Only two wires are used for communication, two wires are unused or these wires are sometimes used to provide power or other features. We can also use a UTP cable category 5 or 6 to connect the phone and the ONT. It is enough to use only two wires of the UTP cable.

Figure 2. RJ-11
MxU devices have POTS ports, too. These are multi-core ports, and the cable is a multi-core symmetric twisted pair cable. The connector is called a D-type, and it is a 68-pin male connector. The example of the MxU device is shown in figure 3.

Figure 3. SmartAX MA5616
Some telecommunications operators offer the service of classic analog (Analogue Modulation CATV) and digital television (DVC standard for Europe). An RF (Radio Frequency) port is required to enable this service on the ONU device. We can see this port in the first figure, on the right side (CATV). The cable for connecting the TV on the ONT is coax cable RG-6. Connectors are F connector (side for ONT) and P1 connector (side for TV).
This is the end of this topic. I hope you learned something new.
For more information, please click:
ONU service interfaces (1): Ethernet interfaces
ONU service interfaces (2): WiFi
ONU service interfaces (3): Basic WLAN configuration
Thank you!



