What is the difference between ONU and Router?

  • Thread starter Thread starter ACKR
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Hello i recently upgraded from ADSL to fiber and BSNL provided me with ONU equipment. I had placed an order for TP-Link C6 but is there a need for it with ONU? i was thinking to replace the ONU with the router but apparently ONU is must for this process to take place.I already have a TP Link Router set as access point to extend the connection so is there any need for router if i can't replace the ONU with it?
 
ONU is the device that converts fiber optic to ethernet signals.

When ISPs provide ONUs with WiFi/Multiple Ethernet ports etc they are providing a combo unit that can do routing, switching and have a WiFi Access Point built in.

There are basic ONUs too with single ethernet port and no WiFi and these are intended to be used in bridge mode. In bridge mode, the ONU functions as a simple fiber to ethernet converts rather than as a router/WiFi combo.
 
it reduces the load on ONU's CPU. Also, routers (seperate from ONU) have more features.

Double NAT occurs when you connect ONU to Router with ONU in route mode. This means usually worse performance (because NAT puts strain on both CPU/RAM of ONU and router) and harder time configuring port forwarding.
 
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When I converted broadband connection to FTTH, my provider gave Digisol ONU.
From last 2 days, I was getting 2-3 Mbps while I have 30 Mbps plan.
After troubleshooting with Customer support, we found speed received through ONU (by directly connecting laptop to ONU's Ethernet port) was 30 Mbps, but Router was reducing speed. After Router was Reset, speed through Router was also 28-29 Mbps.
I asked why speed was lower through Router, Support person said may be Router was getting loaded. I had enabled Guest network few days back, wondering whether that could be reason.
 
Multiple SSIDs (incl guest networks) aren't that hard on CPU. Might be a software bug that was causing it.
 


it reduces the load on ONU's CPU. Also, routers (seperate from ONU) have more features.

Double NAT occurs when you connect ONU to Router with ONU in route mode. This means usually worse performance (because NAT puts strain on both CPU/RAM of ONU and router) and harder time configuring port forwarding.

i'd like to add that my router (archer c6) is getting firmware updates once or twice a year. So hopefully its more secure than my el cheapo ONT.

Also, regarding "had placed an order for TP-Link C6 but is there a need for it with ONU?" My onu would not handle dhcp properly for 5-6 devices. A devices restarted would sometimes not get ip. These problems werent there with the C6, even with 20+ devices.
 
Thanks this might be a bit unrelated but suppose i want the onu connected to a router and a access point somewhere else in the house connected to the router then i would have to set 3 subnets right?

like 192.168.1.1 for onu
192.168.2.1 for router
and 192.168.3.1 for the access point?

Also i am thinking of following this guide to setup, I have a question what does Turn off lan DHCP do? some places say to do it others not.

Also my model of ONU is Syrotech SY GPON 2010 WADONT so if anyone has done Bridge mode with this model and can send pics of settings then it would be highly appreciated.
 
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@ACKR Access Points don't need its own subnet, it works on your existing LAN of router. I would suggest setting the IP of AP to something high like 192.168.2.200 .

If your Router has a Access Point mode, then you can use that (as AP Mode turns off DHCP).

However some routers don't have AP mode in which case turning off DHCP in settings is needed to prevent clients from leasing IP Configuration from the AP instead of the router like its supposed to.

Make sure to plug into LAN of the AP (not WAN Port).
 

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