Calls always income as missed ones without ringing and Signal doesn't report the call failed

[szotsaki]

Please, report issues only from version 5.6 upwards!

General complaints forum and user help-out on this issue: https://community.signalusers.org/t/make-signal-calls-reliably-ring-on-the-receiver-side/18510

• [X] I have searched open and closed issues for duplicates
• [X] I am submitting a bug report for existing functionality that does not work as intended
• [X] I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• [X] This isn't a feature request or a discussion topic

---

Bug description

Users are welcome to re-submit bug reports

When Signal is opened in front of me on my phone and via Hangouts PC I hear the other party while his Signal is actually ringing me. My Signal shows no sign that I'm being called. At the end of ringing, when the network automatically disconnects, I immediately receive a "You have a missed call" notification in the chat.

Reproduced on three different WiFi networks with the same person.

The time difference between the two phones is approximately 5 seconds. Both phones are set to synch to carrier time.

Steps to reproduce

• Make phone A call phone B in Signal
• Observe that phone B gets no notification about the incoming call just the missed one.

Actual result: Call arrives as missed one. Expected result: Phone B rings.

Screenshots

Device info

Device: Sony F5121 Android version: 7.1.1 Signal version: 4.14.10

Link to debug log

Callee debug log: https://gist.github.com/anonymous/9984ab543d85a181b06b02954564c060 Caller debug log: https://gist.github.com/anonymous/5eae662fee114e5e07a72dbd02c0e92d

Original report: #7314

@moxie0:

According to the logs in the issue, the devices are not able to find a valid ICE candidate.

Please, unambiguously tell the user there is an error happening during the call and the call has never been initiated.

References: #7603

Since this bug report is specifically about the non time-sync issue, there's another one for the time-sync problem. Please, don't clog this report with NTP-timing issues anymore but you're more than welcome to add your comments in and subscribe to #9633. Thank you.

[moxie0]

Do either of you have a VPN enabled?

[cegg1]

In my case I don't have a VPN or Tor enabled on any of the phones and neither do my contacts.

[szotsaki]

In my case I have DNS66 enabled (which is an "in-phone" VPN for ad-blocking) but several times applications circumvent it. My contact doesn't have a VPN.

[moxie0]

@szotsaki Can you try disabling and retest?

[alandom]

i have the exact same issue with my signal. please let me know if you solve the issue.

[erik55]

I have the same issue. Sometimes calls work, sometimes I only get a missed call message (Samsung S7 phone and Samsung S5 mini on the other side).

Another thing: When we are calling each other at the same time, no connection is achived/no call is coming in, neither is there a callee busy sign/tone.

How could I help improve this?

[hbasold]

I can confirm that the same happens also for calls between a Fairphone 1 (Android 4.2.2) and an iPhone in both directions. Please let me know if you need anything.

[szotsaki]

If you want this fixed sooner, please provide:

• whether you use any kind of VPN on your phone;
• whether you live in a country in which Signal can be blocked;
• networks of both phones (WiFi, GSM etc.);
• logs from "Settings > Advanced" right after the unsuccessful calls from both phones.

I myself can retest the VPN-less solution a bit later.

[erik55]

When I experienced this, both phones were connected via WiFi, no VPN. At the moment I can’t reproduce this. (maybe one of the WiFis was bad, slow?).

But still: When we are calling each other at the same time, no connection is achived/no call is coming in, neither is there a callee busy sign/tone. It just submarine echoes for ever. Separate bug?

[haffenloher]

@erik55

When we are calling each other at the same time, no connection is achived/no call is coming in, neither is there a callee busy sign/tone. It just submarine echoes for ever. Separate bug?

Yep. You could open a new report for that if you like.

[erik55]

The last thing, I mean when we are calling each other at the same time, seems to work now: I hear that the busy sign/tone.

And now I can always call, but the other person can't call me anymore (I only get messages: Missed call). When I read that I can at least call back.

[szotsaki]

@erik55: could you please answer the comment above you to make it easier to fix this bug?

[erik55]

OK, both phones are now in the same WiFi. The Samsung S7 has always the Signal beta version, the Samsung S5 Mini the regular version.

Problem: S7 can call S5 Mini, but S5 Mini can't call S7.

Successful call from S7 to S5 Mini

• S7 log

• S5 Mini log

Now try to call from S5 Mini to S7

I hear submarine echo on the S5 Mini, and immediately get a message of a missed call on the S7, while the S5 Mini continues to submarine echo.

• S7 log

• S5 Mini log

[erik55]

This is all so buggy!!!

I tried the same with the mobile network, WiFi deactivated. No connection at all. And messages from S7 to S5 Mini arrive quite fast, but messages from S5 Mini to S7 take 5 or 10 minutes (some only arrived after putting the S5 Mini in the WiFi again). But the mobile network on the S5 Mini seems bad, because it changes from H+ to 3G every few seconds.

I put both phones in the WiFi again, send some messages in both directions and was then able to establish a call from S5 Mini to S7!!

• S5 Mini log

• S7 log not possible, because every time I click on Advanced, Submit diagnose log I see for a few seconds Loading logs… and then Signal stopped, restart Signal app. Annoying.

[erik55]

It seems to work now in both directions both with WiFi and mobile network. Messages also are sent and received immediately.

S5 Mini log

S7 log still not possible, it always crashes. That seems to be the solution: If the logging on the S7 crashes, then connection is working.

I will now restart the S7 phone to make it work again (the logging).

S7 log right after restarting

[erik55]

Still seems to work in both directions after restart of S7. The connectivity seems to be somehow established.

[mpiffault]

Same problem here :

• No VPN on both phones
• France (I don't think it can be blocked for the moment)
• GSM for both phones
• Moto G on Android 5.1 for both devices

Sometime call pass, sometime not. I'll come back with logs later.

[mirasPL]

I cant call to my contacts all the time conecting but my contact can call me not every time but they can. Text is ok. Android 8.1.0 One plus one Ireland

[szotsaki]

@mirasPL Please, attach logs right after the failed call attempt described in the comment above. Do you have VPN enabled?

[mirasPL]

https://debuglogs.org/6926f8a7ed3e901e2aef5f86aed86317ba7040827fe1944eb06b8d8c6f08fe3b This is my logs after failed call no VPN

[szotsaki]

Now I could reproduce the issue. The following logs are from the receiver side.

• With VPN (DNS66 ad-filter) turned on LTE-LTE didn't work. Log: https://debuglogs.org/6c5af80a13d7ddf016349d6bbecb9ed8a0af4d2cd89aeb7aaa3624835b33936d
• Without VPN (put to the exception list) WiFi (receiver side), LTE didn't work. Log: https://debuglogs.org/0745f9ed9d3e217c57e5301b0df6ac15001a6ce912692af023c17d3baf522a15

"Didn't work" means that only the notification arrived that I have a missed call. You can compare the two logs and possibly find out whether VPN has any importance regarding this issue.

Countries: don't block apps and sites.

Android: latest 8.0 Signal: latest version.

Do you need any other information we can provide to you?

[Frejr]

I have this problem too. Almost. I can make and receive calls, when I'm connected to WiFi . My phone operator seems to give me only IPv6 address (IPv4 available over tunnel), so maybe somewhere here's the problem (or Android version).

Testing: Two phones with the same mobile operator (no VPN connections).

• my: WiFi, second: LTE (calls possible)
• my: LTE, second: LTE (calls imposiible)
• switching between cell-network and WiFi on the second phone not done yet, but I asked someone else for this and still problem only when my phone isn't WiFi connected.

Others unintentional "tests" shows, that problems appears only when I'm not WiFi connected. All other function works fine (messages, pictures and attachments) and are not network type dependent.

Apps on both ends were killed and started again - I found it helped to someone. No positive results.

Here's first log (my phone): https://debuglogs.org/764d4007a185cdc40ad90f8afcc356091abcb5e861e2c4a76bf8be0eab54589d

And the second after reboot (without connect to WiFi on start - also my device): https://debuglogs.org/b588786285c1e2031d3e7bd1f6e91722bb2dc966181d216bf33669b9274ce578

Please let me know if I could give any more data, because problem is little bit annoying.

[kuala-lumpur1]

I can confirm the problem. I have the same problem and tried on both Android and IOS and Signal is not blocked on my country and i don't use VPN or Tor on both devices.

For me to solve this issue, I just switch between the Wifi and Mobile network and trying to call about 3 to 4 times until the call established successfully.

Sometimes it works when both phones are connecting to Wifi .. and sometimes it works when one device is on WiFi and the other one is on Mobile network.

[ghost]

This issue seemed to resolve itself for me when I stopped using a DNS changer. I was using the application DNSChanger and with it enabled calls did not work on neither LTE or WiFi. I suppose this may be he same issue as it working with VPNs. This shouldn't be the case though. My Wi-Fi network uses a local DNS and it seems to work fine, but when I try to change the DNS on the device specifically (Android phone), Signal calls fail.

[Champion0081]

@kuala-lumpur1 @Frejr @szotsaki Hey guys, i believe i observed similar problem and it seemts to be ipv6 related. The issue described above is visible on my Orange LTE in Poland . By default the APN is "internetipv6" which provides the phone IPv6 address ONLY to the phone. You can change the apn to "internet" and get an IPv4 address (private one).

In both scenarios text messaging works fine, the issue is with the calls.

On ipv6 only APN on android :

• when i call somebody i can see "dialing" forever, signal is not ringing on the other side
• when sb calls me i cannot see his call

On ipv4 only APN on andoid:

• usually when i call somebody i can see "dialing" then "connecting" (and stuck here). on the other side user is able to accept the call but he does not hear or see me (call seems established).
• when sb is calling me when i am on ipv4 APN i am able to receive call without issues, audio and camera image on both sides are fine.

Can someone look into this? Seems like the ipv6 only connection seem to make a difference. The carrier (Orange Poland) claims they do not shape traffic in any way that can cause Signal or any other app to malfunction. Please note that Orange has a long story of routing all traffic outside it's network from Poland through Germany (Frankfurt) and to the other ISPs from there.

Device: Samsung Galaxy S7 SM-G930F OS: Oreo 8.0 (XEO unbranded official rom for Poland)

[Frejr]

@mattimac: Yes! YES! YEEEEEEESSSS! It is! This helped! Tank you! I din't know, that I can change it!

So… We have one thing what causes problems. ONLY IPv6 protocol.

[kuala-lumpur1]

@mattimac
Can you explain how to change the apn to "internet" and get an IPv4 address (private one) ?

I'm having this issue with both Wifi and Mobile Network !

@moxie0 Is there any update regarding this issue ? maybe the reply of @mattimac can help ?!

[vipulparashar]

Go to seetings - click on 'more' - Click on 'Mobile Networks' - Click on 'Access Point Names' - Click on your 'APN' - Click on 'APN PROTOCOL', Update it to 'ipv4'

This is valid for mobile networks only.

[Champion0081]

Anything more we can do to draw devs attention to it?

[kuala-lumpur1]

I just checked my mobile and actually it's By Default set to IPv4.

Still hope to find solution for this problem