Guide Using an IP Phone with Airtel Fiber (VoIP Setup)

[anmolbhard004]

If you've ditched Airtel’s default ONU and are now using an SFP or a third-party ONU, you can still set up an IP phone to make unlimited calls over Airtel Fiber.

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Understanding Airtel's VLAN Configuration​

Airtel uses two VLANs:

• VLAN 100 – For internet
• VLAN 660 – For voice services

In most areas (99%), this setup is standard, except in locations with an ALCL OLT, where VLANs might differ. However, you can easily perform a VLAN scan to determine the correct VLAN IDs in your region.

Requirements​

1. VoIP Credentials– These can be extracted from your Airtel-provided router.
   • If you have a ZTE or Nokia router from Airtel, the credentials are visible in the VoIP section.
   • If you have a different router, you may need to inspect the webpage's elements to extract them.
   • 
     
2. IP Phone – The cheapest models start at around ₹1,500.
3. A Managed Switch (optional) – Required for VLAN segregation if your router doesn’t support multiple VLANs on the WAN port.

Steps to Configure VoIP on Airtel Fiber​

1. Segregate VLANs – You need to send:
   • VLAN 100 to your router (where PPPoE or static IP is dialed).
   • VLAN 660 to your IP phone for VoIP services.
2. Example Setup (Using a Managed Switch)
   • Port 10 → SFP (HSGQ) untagged/transparent VLAN
   • Port 9 → Tagged with VLAN 100, connects to the WAN port of your router (Ubiquiti/TP-Link/MikroTik/PFsense).
   • Port 8 → Tagged with VLAN 660, connects to the VoIP phone, where you enter the credentials.
3. 
4. Final Steps
   • Configure your router to dial the internet using PPPoE/static settings.
   • Enter the VoIP credentials into your IP phone.
   • Done! Your VoIP phone should now work seamlessly.

Additional Notes​

• The overall idea came from Ubiquiti forums. If you use OpenWRT, MikroTik, or TP-Link devices, the setup is straightforward.
• Ideally, Ubiquiti should support multiple VLAN tagging on the WAN port, but since it doesn’t, a TP-Link managed switch was used for VLAN segregation.
• If using MikroTik or OpenWRT, VLAN handling can be done within the main router itself (where the SFP is plugged in).

Resources​

• Community post: UBIQUITI

Also, there is a video on YouTube as well on how to set up the VoIP phone with Airtel have a look

@napstersquest you might now think to use a sfp in future now

Also a big thank you to @ishanjain28 @dhyaneshwar94 @smnrock @SayantanGR for helping out at every step in setting it up

 

[sauravghosh]

I'll have to reborn like 69 times to get this. But still must ask Outta curiosity. Can you make calls anywhere I mean isd calls too?
Thank God my router is neither nokia nor zte. It's some zyxel. So it won't work me. Super happy. No temptation.

 

[anmolbhard004]

It's some zyxel.

hehe it works for that as well just need to use inspect to check the credentials nothing else

Can you make calls anywhere I mean isd calls too?

you cant.

 

[napstersquest]

@napstersquest you might now think to use a sfp in future now

Now.... have to *steal* borrow an IP phone from the office (I have like a hundred just sitting at my work desk XD)