Jio WiFi calling on Airtel Broadband

[thescurvydawg]

I used to have Spectra and Jio WiFi calling on the iPhone used to be seamless. Switched to VoWifi as soon as it connected to the Wireless network. With Airtel, this is spotty. Sometimes it connects, sometimes it doesn't. Rebooting the phone or the router doesn't seem to help.

However, if I switch to Cloudfare DNS from Airtel's DNS on my router, VoWifi is perfect again. Has anyone else observed this? Is Airtel deliberately blocking Jio VoWifi?

 

[Sushubh]

Jio VoWiFi has Issues with dns servers outside India which should not be the case with airtel dns so hard to say.

 

[thescurvydawg]

Weird. I can definitely reproduce this problem on multiple Apple devices
1. Jio SIM, Airtel Xstream with Airtel (Default) DNS - Flight mode ON, OFF <--Takes 1-2 minutes for VoWIFI to turn ON
2. Airtel SIM, Airtel Xstream with Airtel (Default) DNS - Flight mode ON, OFF <--Immediately switches to VoWIFI
3. Jio SIM, Airtel Xstream with Cloudfare DNS - Flight mode ON, OFF <--Immediately switches to VoWIFI

Not too bothered by it, will stick to Cloudfare DNS

 

[varkey]

Yeah as @Sushubh mentioned, Jio VoWiFi appears to be extremely picky with respect to the DNS resolvers used. My initial observation was that they are looking for resolvers in India. However, over the last 1-2 days, I was evaluating using unbound as a local recursive resolver and noticed the same issue. In this case, the IP address seen by Jio's nameservers would be my BSNL IP address which is definitely in India, but it still failed.

Then I switched back to the previous config of using Google DNS as the DNS forwarder and VoWiFi started working again.

🤷‍♂️

 

[amits0809]

I had similar issue. Was unable to use jiotv app, jio cinema and jio wifi calling on my iPhone. I tried resetting router as well but lost Voip setting. Nothing worked for me. Then i changed dns to clouldflare. I think issue is with DNS. If you change to adguard dns, jio services gets blocked.

 

[varkey]

I did some digging, so it appears the DNS name vowifi.jio.com resolves differently based on the source IP address of the resolver (or maybe they do make use of the EDNS-Client-Subnet mechanism also, I did not test that).

So from India it resolves to 49.44.59.38 & 49.44.59.36, but from anywhere else it resolves to 49.45.63.2 & 49.45.63.1. The above image is from OpenDNS cache check (OpenDNS: Cloud-Delivered Security Enforcement and Intelligence) where you can check how the name resolves from various geographies.

So my guess is, they have this mechanism probably to support VoWiFi during international roaming. When outside India, you get redirected to a different endpoint, and the VoWiFi is enabled only when the required plan or addon is active.

The setup is a bit weird, if I ask ns1.jio.com which is one of the nameservers for jio.com, it says go ask ns1/2.vowifi.jio.com. But they are missing the DNS records for ns1.vowifi.jio.com and ns2.vowifi.jio.com, but they do send the glue records, so it does work.

(⎈ |docker-desktop:default)➜  ~ dig vowifi.jio.com @ns1.jio.com.

; <<>> DiG 9.10.6 <<>> vowifi.jio.com @ns1.jio.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3137
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;vowifi.jio.com.            IN    A

;; AUTHORITY SECTION:
vowifi.jio.com.        3600    IN    NS    ns1.vowifi.jio.com.
vowifi.jio.com.        3600    IN    NS    ns2.vowifi.jio.com.

;; ADDITIONAL SECTION:
ns1.vowifi.jio.com.    3600    IN    A    49.44.59.6
ns2.vowifi.jio.com.    3600    IN    A    49.44.59.7

;; Query time: 60 msec
;; SERVER: 2405:200:1602:720::4#53(2405:200:1602:720::4)
;; WHEN: Thu May 21 11:15:07 IST 2020
;; MSG SIZE  rcvd: 111

But the issue I am facing at times is that vowifi.jio.com resolves to the international IP addresses and VoWiFi doesn't work. I do use a caching resolver, so I am trying to pinpoint the actual problem. However, I can definitely say that this isn't set up properly from Jio's perspective.

 

---

[Sushubh]

NextDNS I think has an option where you can bind a domain with a specific ip like you do with host file... 🤔

 

[varkey]

So in my case, all my devices are pointed to a local caching resolver, and I could if required bind that record to a specific IP address. But what if they change it? I was looking for a proper solution where the name reliably resolves to the right IP addresses. 😅😅

Yep, you could add an override in NextDNS too which is a cool feature. I had to stop using NextDNS as it didn't play well with Stubby (which I am using as a stub resolver for DoT). Maybe things have improved now, I really did like NextDNS for the reporting data they provided 😅😅

 

[thescurvydawg]

I did some digging, so it appears the DNS name vowifi.jio.com resolves differently based on the source IP address of the resolver (or maybe they do make use of the EDNS-Client-Subnet mechanism also, I did not test that).

View attachment 1891

So from India it resolves to 49.44.59.38 & 49.44.59.36, but from anywhere else it resolves to 49.45.63.2 & 49.45.63.1. The above image is from OpenDNS cache check (OpenDNS: Cloud-Delivered Security Enforcement and Intelligence) where you can check how the name resolves from various geographies.

So my guess is, they have this mechanism probably to support VoWiFi during international roaming. When outside India, you get redirected to a different endpoint, and the VoWiFi is enabled only when the required plan or addon is active.

The setup is a bit weird, if I ask ns1.jio.com which is one of the nameservers for jio.com, it says go ask ns1/2.vowifi.jio.com. But they are missing the DNS records for ns1.vowifi.jio.com and ns2.vowifi.jio.com, but they do send the glue records, so it does work.

(⎈ |docker-desktop:default)➜  ~ dig vowifi.jio.com @ns1.jio.com.

; <<>> DiG 9.10.6 <<>> vowifi.jio.com @ns1.jio.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3137
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;vowifi.jio.com.            IN    A

;; AUTHORITY SECTION:
vowifi.jio.com.        3600    IN    NS    ns1.vowifi.jio.com.
vowifi.jio.com.        3600    IN    NS    ns2.vowifi.jio.com.

;; ADDITIONAL SECTION:
ns1.vowifi.jio.com.    3600    IN    A    49.44.59.6
ns2.vowifi.jio.com.    3600    IN    A    49.44.59.7

;; Query time: 60 msec
;; SERVER: 2405:200:1602:720::4#53(2405:200:1602:720::4)
;; WHEN: Thu May 21 11:15:07 IST 2020
;; MSG SIZE  rcvd: 111

But the issue I am facing at times is that vowifi.jio.com resolves to the international IP addresses and VoWiFi doesn't work. I do use a caching resolver, so I am trying to pinpoint the actual problem. However, I can definitely say that this isn't set up properly from Jio's perspective.

Great, good research, looks thorough.

Also, somehow my problems with Jio VoWifi and Airtel Broadband seem to be OK since yesterday

 

[SVK]

If we use Jio VoWifi on some Broadband to call non-Jio number, will it consume non-Jio minutes from balance?

 

[varkey]

@SVK Yes, VoWiFi only helps in low signal areas, all other terms remain the same.

 

[Gokul Kannan]

@SVK yes, billing is same as VoLTE, only difference is in VoWifi your call will be routed through your BB from last mile instead of using Jio's network

 

[thescurvydawg]

If we use Jio VoWifi on some Broadband to call non-Jio number, will it consume non-Jio minutes from balance?

VoWiFi has nothing to do with calling rates. All rates on VoWifi are same as VoLTE

 

[igloo]

yes. call rate/usage is same regardless of vowifi or volte.

 

[pswapneel]

I did some digging, so it appears the DNS name vowifi.jio.com resolves differently based on the source IP address of the resolver (or maybe they do make use of the EDNS-Client-Subnet mechanism also, I did not test that).

View attachment 1891

So from India it resolves to 49.44.59.38 & 49.44.59.36, but from anywhere else it resolves to 49.45.63.2 & 49.45.63.1. The above image is from OpenDNS cache check (OpenDNS: Cloud-Delivered Security Enforcement and Intelligence) where you can check how the name resolves from various geographies.

So my guess is, they have this mechanism probably to support VoWiFi during international roaming. When outside India, you get redirected to a different endpoint, and the VoWiFi is enabled only when the required plan or addon is active.

The setup is a bit weird, if I ask ns1.jio.com which is one of the nameservers for jio.com, it says go ask ns1/2.vowifi.jio.com. But they are missing the DNS records for ns1.vowifi.jio.com and ns2.vowifi.jio.com, but they do send the glue records, so it does work.

(⎈ |docker-desktop:default)➜  ~ dig vowifi.jio.com @ns1.jio.com.

; <<>> DiG 9.10.6 <<>> vowifi.jio.com @ns1.jio.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3137
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;vowifi.jio.com.            IN    A

;; AUTHORITY SECTION:
vowifi.jio.com.        3600    IN    NS    ns1.vowifi.jio.com.
vowifi.jio.com.        3600    IN    NS    ns2.vowifi.jio.com.

;; ADDITIONAL SECTION:
ns1.vowifi.jio.com.    3600    IN    A    49.44.59.6
ns2.vowifi.jio.com.    3600    IN    A    49.44.59.7

;; Query time: 60 msec
;; SERVER: 2405:200:1602:720::4#53(2405:200:1602:720::4)
;; WHEN: Thu May 21 11:15:07 IST 2020
;; MSG SIZE  rcvd: 111

But the issue I am facing at times is that vowifi.jio.com resolves to the international IP addresses and VoWiFi doesn't work. I do use a caching resolver, so I am trying to pinpoint the actual problem. However, I can definitely say that this isn't set up properly from Jio's perspective.

@varkey I have been looking at this issue for sometime now and running a few measurements of my mine. It appears, from every location outside India, vowifi.jio.com resolve to 49.45.63.1 and 49.45.63.2. However, from within 75 networks within India, a pattern has begun to emerge, there were considerable number of networks where vowifi.jio.com resolves to 49.45.63.1 and 49.45.63.2 & there is a local DNS resolver in the network 🙂

Having said that, there were also also networks which were using ISP DNS resolver or one of the cloud/quad DNS provider, where vowifi.jio.com resolved to 49.45.63.1 and 49.45.63.2. In short, the pattern isn't separating the white from the black. 75 is a small sample size to begin with.

Here is a quick question for you/anyone in this forum for whom Jio VoWiFi isn't working, from the same network, if you use your ISP DNS resolver or any of the cloud/quad DNS resolver, can you share the results of dig/nslookup here ? If you do not have access to a computer/laptop and want to share results from your phone, I recommend installing the Hurricane Electric Network Tools app

Edit - Fixed semantic errors in the comment by replacing with a strikethrough.