Connect Mobile SIP application to GrandStream UCM6304A



I have a GrandStream UCM6304A device and I want to connect SIP flutter application ( ) to be able to make only SIP call. but the application uses SIP over websocket.

How can I connect this application to GrandStream over WebSocket?



you don’t need to open any doors, and the only official app for UCM630x is Wave,
here is how to use it:


Dear user,

Thank you for using the UCM63xx and Wave application! As Damiano70 claimed, you can use Wave application which is our official compatible application with your UCM63xx. You can use the Wave application and it will meet your requirements. Thanks for your testing!

Thank you!


Thanks for quick reply,

My mobile application will not only sip but also many other features such as mapping, navigation and so on. Therefore my application should be able to make sip call as well. That’s because I need a sip implementation in my code. I will be thankful if you could show me the way.



You can open SIP up from the internet to your system BUT. you will invite the world to hack you.
Since you are mobile the IP address can’t be determined for a proper ACL filter.
Can you use it over the Local wifi?

Best to use the Wave application if possible


this is a Grandstream Products forum, above I put the Grandstream documentation where you can find answers to your questions,
also SIP and WebRTC are two very different things,
for what is not related to Grandstream, you will be able to find assistance in the product you indicated.


Yes you are right, all my clients are in a closed Wi-Fi ecosystem and the only way to communicate outside of the ecosystem is done by GrandStream. Because GrandStream port is connected to telecom.


I guess I am very correct place to discuss the product that I bought. Because I have be sure if the grand stream meets my needs as it is written on its data sheet!

I need to make a sip connection over grandstream as a sip server by my own code not by grandstream wave!


in fact you will get all the answers regarding Grandstream,
and above you have the link, otherwise it is not the correct place,
Grandstream above has already answered you
also this is a user-user forum,
Grandstream support can be found in the link below:


I see you try to say that its a big mistake to buy a such device ! because you are responsible only selling !

thanks …


I do not know what you’re saying,
I just indicated where to read the documentation to resolve your request,
and indicated where to find assistance for Grandstream products,
I can’t do more

good job


right, you can’t !


if you have any other questions about Grandstream products you are welcome,
if you have finished the topics and do not listen to the advice written above,
I have nothing more to tell you.


ok, here is the situation, I am software developer, its a very new domain for me and I try to find something to help me because I don’t have knowledge as you have. Thats why I might asked very simple (maybe stupid) questions sorry for that but I have been lost in documentation already.


no question is stupid,
a SIP phone/softphone registers with UCM like any other registers with a VoIP server,
WebRTC is a similar but different technology to the SIP protocol.
The SIP world almost always allows SIP users to register in the SIP “world”,
instead WebRTC provides different features of operation to another,
what you can do is use WAVE (which is a WebRTC sw from Grandstream)
and see how it works
at that point you use your knowledge as a programmer to apply the possibility of integration to your sw.


thanks, if you dont bother me, let me ask a final question,

my requirement is; clients can make/receive a call to/from PBX over GrandStream by my application.

For this, should I implement SIP or WebRTC protocol? because as you said before SIP and WebRTC are two very different things however wave is a WebRTC application. in this point I confused.


you can try, but WAVE is a Grandstream proprietary WebRTC protocol


your software your code is on the client side. The UCM is an open-stand sip device. The UCM is the server and your application is the client

If all is correct on your end there should be no issue connecting to the sip B2B user agent, in this case, the UCM i.e the server. So this can defiantly meet your needs.

I think since you are the developer all you need form the community is to confirm if the UCM can work and since it is open standard sip device it can work the rest I am afraid is up to you as the developer


hi Neeraj.
maybe you’re missing one thing, that’s a WebRTC client, it’s not a SIP client.


yes you correct Damiano he wants to use web rtc. I see that now but in any event maybe it useful for him to know any sip client can connect to UCM is it is open standards.