Category: General

I was using NetLink ONU with one antenna, and it worked perfectly fine. I always get good speed. One day this ONT stopped working, so i had to get new ONT. Internet provided gave me a model with 2 antenna – NetLink HG323RGW.

I was very happy to have this new ONT as it has 2 LAN ports. But it didn’t last long. I started facing problems like slow speed and disconnection. On old ONT, I used to get 120 Mbps speed on speedtest. New device give me approx 90 Mbps on speedtest. Another serious problem i was was whenever i do a speedtest on speedtest.net, the ONT stopped working with RED light.

Net provider replaced the ONT with a new one, this new device also had the same issues. They take the ONT and did some firmware updates, that fixed the problem with speed. But ONT still get rebooted on speedtest.

Some days back, this ONT died again, this time, TX power was not showing, normally it shows something like 2 dBm. Since the ONT was in warrenty period, i get a new device, but i started facing all the problems again. I was like this device is fauty and was looking to buy another ONT.

After spending some time reading the specification of this router and the current router, I noticed one thing. My old ONT says “1GE+1FE+1POTS+WIFI ONU”. I did some search and found out this router has only 1 Gbps LAN port (1GE), other one is 100 Mbps (1FE). So I switched the LAN cable to other port. That fixed the speed issue, I started getting 120 Mbps on speedtest again.

I still faced frequent disconnects and ONT turning off during speedtest. I sent a mail to [email protected] asking if i face similar issue if i buy the newer ONT model listed on their site. They offered to check my ONT over TeamViewer.

They connected to my computer and changed the value of MTU to 1460, that fixed problem with ONT getting restarted on speedtest.

After this fix, I had frequent disconnects, but NetLink support said it can be due to a problem with the Cable operator having some loop, this can happen if there is a MAC conflict in the network. Anyway, this disconnect issue gets resolved by itself after some time.

To find the correct MTU value for your network, you can use the ping command. On Ubuntu, I run

boby@sok-01:~$ ping -c 2 -M do -s 1433 www.serverok.in
PING www.serverok.in (104.28.19.89) 1433(1461) bytes of data.
ping: local error: Message too long, mtu=1460
ping: local error: Message too long, mtu=1460

--- www.serverok.in ping statistics ---
2 packets transmitted, 0 received, +2 errors, 100% packet loss, time 1028ms

boby@sok-01:~$ ping -c 2 -M do -s 1432 www.serverok.in
PING www.serverok.in (104.28.19.89) 1432(1460) bytes of data.
1440 bytes from 104.28.19.89 (104.28.19.89): icmp_seq=1 ttl=56 time=64.6 ms
1440 bytes from 104.28.19.89 (104.28.19.89): icmp_seq=2 ttl=56 time=63.6 ms

--- www.serverok.in ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1263ms
rtt min/avg/max/mdev = 63.624/64.151/64.678/0.527 ms
boby@sok-01:~$ 

Start with a higher value, and lower it gradually until you get a ping response.

In my case value of 1433 resulted in the error “ping: local error: Message too long, mtu=1460”. When I used 1432, I get a ping response. You need to add 28 to this number to get the actual MTU value.

1432 + 28 = 1460

On Windows, you can use ping with different options, see

https://kb.netgear.com/19863/Ping-Test-to-determine-Optimal-MTU-Size-on-Router

You can also contact your ISP (BNSL in my case) to get the correct MTU value.

This device is manufactured by

https://www.vsolcn.com/

Sold in India by

https://netlinkict.com/shop/gpon-ont/gpon-ont-1geife1potswifi/gpon-ont-onu-telephone-internet/

Update 2019-08-05; Everything was working better for 1 day. Today this ONT stopped working again. When i start the device, Power and Loss (RED) light turns on. Don’t get any IP on my network interface. Connecting/disconnecting the FTTH cable don’t make any differnce. Pressing reset button on the ONT did nothing. Cable operator replaced the device with another model HG2801RGW. Since i need 2 LAN ports, i purchased a 5 port Switch TP-Link TL-SG1005D 5-Port Gigabit Ethernet Unmanaged Desktop Switch (Black) from Amazon. The plan is to keep ONT simple. This way i can isolate problems easily. I have a TP-LINK Wifi Router, so don’t really need WiFi on ONT. In future, i can use simple ONT device like 1GE Secure ONU V2801S