Twilio SIP Domain not allowing inbound calls - twilio

I have purchased an US Phone Number on Twilio and associated it with a TwiML Bin.
The content of the TwiML Bin is supposed to redirect call to my SIP Domain:
<?xml version="1.0" encoding="UTF-8"?>
<Response>
<Say>Welcome. Your call will be routed to an agent now</Say>
<Dial>
<Sip>sip:+13365518647#branko.sip.us1.twilio.com</Sip>
</Dial>
</Response>
I have created a SIP Domain Credential
I have created a SIP Domain, added the Credential and enabled SIP Registration. Upon incoming call a welcome message should be played.
When I make a phone call to the purchased phone number the welcome message is played and the call gets redirected to my SIP Domain, but the default welcome voice does not get played. Instead, in the console I get The user you tried to dial is not registered with the corresponding SIP Domain error. I can't figure out what I configured wrong. Shouldn't user registration occur automatically? If not, how do I register the user? Please advise
EDIT: I'm using Zoiper as softphone Client. Using Twilio SIP Domain to make outbound calls

One thing you have wrong here is that when your TwiML bin dials your SIP endpoint, the webhook on the SIP domain will NOT be called. The SIP domain VoiceUrl will be called when you originate a call from the softphone that you have registered with the domain.
You've noticed that the console reports that your endpoint is not registered. Your softphone is responsible for registering itself and your username with the domain when it comes online.
I believe the issue you are having here is that you must specify the edge location in your softphone's domain configuration. Make sure you read the documentation on SIP registration.
Note that the bottom of that documentation has links to download a variety of step-by-step guides on configuring various softphones. I have actually tried to use Zoiper Desktop in the same way you are, but I found that it was not sufficiently compatible -- after successfully registering, it would continually re-register itself with the domain until it hit a rate limit, and then calls would fail. I've been very happy with Bria Solo as a reliable alternative.

Related

Is it possible to make outbound call using SIP to PSTN with Twilio?

What I'm trying to achieve is the following: Use Twilio's Voice API to make an outbound call to a PSTN mobile number, however, instead of using Twilio's routing (which is 10x more expensive than normal SIP providers in my region), I want to use a 3rd-party SIP Trunk to perform the call.
The two areas I can't figure out are:
Can Twilio even do this when using a standard SIP Trunk
And/or, does the SIP Trunk need certain features for this to work (so I can't just signup for any old SIP Trunk)
I see Twilio can dial a SIP URI, however, I can't see how the SIP Trunk will route that call to the PSTN (ie. it seems it can only dial the SIP user as the final destination). Twilio has recently introduced BYOC - https://www.twilio.com/docs/voice/bring-your-own-carrier-byoc - which looked hopeful, however, when setting up the Origination Target you can only provide the SIP URI. This is the technical point I don't really understand, since my SIP Trunk requires a username and password to authenticate before making a call, and the BYOC setup doesn't offer this. Is there some special feature the SIP Trunk needs to work?
I think I'm missing something fundamental here, because I can't see a way of making this work (maybe it's not possible without a very specialized setup). So any help getting on the right track is appreciated (I did try Twilio Support, but they seem as clueless as I am).
So I can answer my own question for anyone coming across this post. You can use a standard SIP Trunk with Twilio's BYOC. Twilio sends an INVITE request to the SIP address entered in as the Origination on the BYOC setup. However, it must use IP address authentication - there's no way to use standard SIP credential authentication.
The ip addresses used depends on the DC it's coming from. See signalling IPs here - https://www.twilio.com/docs/voice/api/sip-interface#ip-address-whitelist
You can also append the "edge" parameter in the Origination SIP URI to dictate which Twilio DC it comes from - https://www.twilio.com/docs/voice/api/receiving-sip#SIP-URI-edge
For additional security, you could consider Twilio's private Interconnect option, or you could append some custom arguments to the SIP URI, which could be authenticated on the SIP Trunk side when it receives the INVITE - however, this would require a custom setup to achieve that, and whatever argument you use for authentication would be visible in the URI.

Transfer call from SIP trunk to Twiml application

I have a phone number registered in Twilio that I wanted to use for both a Twiml application and an Elastic SIP Trunk (connected to Asterisk). The idea is that inbound calls hit the Twiml app first and then can be forwarded to the Asterisk server if needed, while outbound calls just go via the SIP trunk. (The reason it needs to be a SIP trunk instead of simply using SIP Registration with Programmable Voice is because that is the only way to have E911 support for outbound calls.)
Twilio support told me that it is not possible to use the same number for both.
Because of that limitation, my current plan is to use two Twilio phone numbers. My published phone number will go to the Twiml application, and a second number that I will not give out will go to the SIP Trunk. (Twilio allows number spoofing of other numbers on your account, so I will have the Asterisk server pretend to use my primary number for outbound calls instead of using the second private number.)
In order for this to work, I need to be able to transfer calls from my Twiml app to Asterisk and from Asterisk server back to the Twiml application. The former is easy: just use <Dial> with a SIP URL that points to the trunk. The latter is what I need help with. (I also want to do this in case someone does manage to call the second number - I want them to be redirected to the Twiml app.)
As far as I can tell, the only way for me to transfer calls back into my Twiml application is to forward the call from the Asterisk server back to my public number. The problem is that I think this will look like an outgoing+incoming call and I will get double-billed for these minutes. I'm already paying for another number, and I really don't want to have to pay extra for the minutes too.
Is there a better (or "official") way to transfer a call back to the Twiml app? Or am I wrong about Twilio seeing (and billing) this as two calls?
It is not clear why you cannot use the Twilio number for both a Twiml application and an Elastic SIP Trunk (connected to Asterisk). Did they indicate why?
Just don't assign that particular number to your Elastic SIP Trunk and you should be able to assign it to your TwiML application for inbound calls and use a when you want to forward the the call to your Asterisk PBX.
For outbound calls, you can have you Asterisk PBX send calls with that number as CallerID to your Elastic SIP Trunk Termination URI.
For E911 calls from the Twilio Elastic SIP Trunk, you should have a number associated with your Elastic SIP Trunk, enabled for Emergency Calling, so when 911 calls are placed, the CallerID of that number is used for outbound calls and calls can be returned to that number should the connection get disconnected.
If you did go the second route you mentioned, can you have your Asterisk Server send the call to a Twilio Programmable Voice SIP Domain, maybe have a Dial Plan defined so an Asterisk prefix digit sends calls out this different trunk. Not sure this will work (since mixing Elastic SIP Trunking with Programmable Voice in this manner) but one idea. Your Asterisk server will remain in the call path.

Register Twilio as extension/endpoint SIP client using username and password

I have the next situation:
A call is made to a PSTN/DID number of my phone company and that I can use with proprietary SIP cell phone app or SIP client application like Zoiper / Linphone configuring with SIP, user and password.
I cannot configure this service to forward a call to 3rd party service SIP URI. I've already asked it to my PSTN provider and they say that it is impossible.
The question is:
How can I make Twilio (or maybe another service) register as SIP client with user and password (like extension/endpoint ) to receive a call from PSTN and forward it to other SIP URI or phone number?
I know that asterisk / some cloud pbx can do it like it was previously free account at pbxes.com.
Have you considered porting your number to a carrier that will allow you to forward inbound calls to a specific SIP URI you configure or register for calls to that URI, given your current carriers constraints?
For example, Twilio has some documentation here on porting a number.
International Porting
Porting a number To Twilio
I understand, based on your country, this may not be an option.
Twilio does not have a way to register as a SIP client with another provider. It does offer the ability of using a Twilio hosted number (and thus the comment on porting) to register a SIP client against or forward a PSTN call to a SIP User Agent.

Can I return a SIP 302 (Redirect) as a response to an incoming call to my Twilio app?

I would like my Twilio app to be able to redirect the inbound SIP INVITE to a different telephony system in some cases. We are not using Twilio's carrier but using our own (thinQ) for origination and termination via SIP.
I do not want to forward the call via the Dial command as it would keep the Twilio app in the loop during call setup.
Is is possible to do this?
Twilio developer evangelist here.
Twilio does not support returning a 302 redirect when receiving SIP as you describe.
When you set up to receive SIP and channel it through Twilio you need to respond to those incoming calls using TwiML and not SIP commands. Like you suggested, you could use a <Dial> which would direct the call elsewhere (including to other SIP addresses if you use <Sip>) but you cannot just respond with SIP instructions or a redirect.
If you do not want these calls to be handled by Twilio, then you will need to adjust your call routing before the SIP is sent to Twilio.

Twilio studio connect call to SIP

I'm trying to setup a simple flow using Twilio studio, with the last widget being "Connect call to".
I want to have a caller connected to an agent with a SIP client, registered with the SIP domain in Twilio. The SIP client that's registered to the SIP domain is nothing but a Bria SIP client iOS app that has successfully registered with the SIP domain.
When I type in twilio's SIP domain details as the end point along with the username and password, the flow gets published fine.
When I test the flow by calling the number that triggers the flow, I do get the options as per the flow. I then press certain keys that triggers the "Connect call to" widget in question. At this point, call ends without connecting to the SIP client. I also see this error event, 32009 - The user you tried to dial is not registered with the corresponding SIP Domain.
Am confused. I tried looking into the documentation on Twilio but no luck.
Did you use the below format, making sure to include the us1 subdomain?
USERNAME#SIPDOMAIN.sip.us1.twilio.com

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