Zubsip · SIP softphone
Zubsip Support
Help with setting up and using Zubsip, the SIP softphone for business voice calls: registering your extension, making and receiving calls, permissions, audio, notifications and network troubleshooting.
What it is
About Zubsip
Zubsip turns your phone into an extension of your organisation's telephone system. It is a client application, not a telephone service of its own.
Zubsip registers to a SIP/PBX account that your organisation or telephony provider issues to you, and then behaves like a desk phone: you can dial internal extensions and, if your organisation allows it, outside numbers. Calls reach you while the app is in the background or closed, because the phone system wakes your device when your extension rings.
Because the calling capability comes from your PBX account, Zubsip cannot place or receive calls on its own. It does not provide a phone number, and it is not a consumer calling app or a messaging service.
You need a compatible SIP/PBX account
Without SIP credentials from your organisation or a supported provider, the app can be installed but cannot register an extension and cannot make or receive calls. If you do not have these details, ask your IT or PBX administrator — support cannot issue them for you.
Setup
Getting started
Five steps, and only one of them needs anything from your administrator.
Install Zubsip
Install the app from the App Store on iPhone, or from your organisation's distribution channel on Android. Zubsip runs on iPhone with iOS 17 or later.
Collect your extension details
You need your company code, your extension number and your SIP password. Your administrator issues all three.
Enter your details and activate
Open the app and enter the company code, extension number and password. The app works out the server address from your company code and registers your extension over an encrypted connection.
Allow the microphone
The first time you place or answer a call, iOS or Android asks for microphone access. Allow it, otherwise the other party will not hear you. On Android, also allow notifications so incoming calls can be shown.
Make a test call
With the status showing as registered, dial a colleague's extension. Then ask them to call you back, lock your phone, and confirm that the call rings while the screen is off.
Before you start
Information you need from your administrator
Zubsip asks for as little as possible. Everything else is derived from your company code.
- Company code
- A short code that identifies your organisation's PBX, for example the code printed on your internal phone documentation. Letters a–z, digits and hyphens only.
- Extension number
- Your internal number, digits only — the same number colleagues dial to reach you.
- SIP password
- The password for that extension. This is not your Symfy or e-mail password, and support will never ask you for it.
You do not need to enter a server address, port or transport: the app builds the server name from your company code and always connects over TLS. If your organisation runs a PBX that is not hosted by Symfy, ask your administrator whether it is compatible before you start.
Device permissions
Permissions the app uses
Zubsip asks for the minimum it needs to work as a phone, and nothing beyond that.
Microphone
Used only to carry your voice during a call. If you deny it, calls still connect but the other party hears nothing. The app does not record calls.
Notifications
On Android, notification permission is required so an incoming call can be shown, including on a locked screen. On iPhone, incoming calls are presented by the system as telephone calls and the app does not request notification permission at all.
Background operation
The app does not need to stay open. When your extension rings, the phone system wakes your device, so calls arrive when the app is in the background and after it has been closed. On Android a temporary foreground service runs while a call is in progress.
Contacts
Not requested. Zubsip does not read your address book. Names on incoming calls come from the phone system, or from labels you type yourself when saving a favourite.
Day to day
Making calls
- Open the keypad, enter an extension or an outside number, and start the call. Whether outside numbers are allowed is set on your PBX, not in the app.
- Tap the call button on an empty keypad to bring back the last number you dialled.
- During a call you can mute your microphone, switch the audio to the speaker, and open the keypad to send tone digits — for menus that ask you to press a number.
- End the call from the app or from the system call screen.
- Recents lists your latest calls with their direction, result, time and duration. You can save a number as a favourite with your own label, and reorder or delete favourites at any time.
- Call history and favourites are stored on your device only. They are never uploaded, so clearing them removes them for good.
Day to day
Receiving calls
- An incoming call appears as a normal telephone call on your phone, with the caller's number and, where the phone system supplies one, a name. On iPhone this uses Apple's CallKit, so the call looks and behaves like any other call.
- You can answer or decline from the call screen, from a locked screen, or from your Bluetooth headset, exactly as you would for a mobile call.
- Calls arrive when the app is in the background and after you have closed it: the phone system sends a wake-up message to your device when your extension rings.
- Your organisation's desk phones ring independently. If no mobile device is registered, or your phone is offline, the desk phone still rings.
- Missed and declined calls appear in Recents with their outcome, so you can see what happened while you were away.
If something is wrong
Troubleshooting
Work down the list that matches your problem. Most issues come down to three things: credentials, internet connectivity, or a PBX setting that only your administrator can change.
Registration and sign-in
Calls
Audio
Notifications and wake-up
Connectivity
Network requirements
Zubsip needs a stable internet connection, and it needs to be allowed to use it.
- Any reasonable Wi-Fi or mobile data connection is enough for a voice call; video is not part of the app.
- Voice quality depends on stability more than on speed. A congested connection produces gaps and robotic audio even when web pages load quickly.
- Corporate firewalls, guest Wi-Fi and captive portals may block telephony traffic. If the app works on mobile data but not on a particular network, this is usually why.
- A VPN can also break calls by sending call traffic through a route the phone system cannot answer on.
- Networks that provide IPv6 only are supported.
- If a network needs to be opened up, your administrator will find the specifics in the section below.
Technical
For PBX and IT administrators
The values below are the ones the current app build actually uses. Anything not listed here should be confirmed with Symfy rather than assumed.
- SIP server
- <companyCode>.pbx.symfypbx.com, derived from the company code entered in the app
- Transport and port
- TLS only, port 5061. The app does not offer UDP or TCP SIP.
- Server certificate
- The certificate chain must validate, and the certificate must match the tenant host. A wildcard certificate for the PBX domain is accepted. A mismatch closes the connection before registration.
- Registration
- One account per installation, with an RFC 5626 instance identifier so that several devices on the same extension are registered as distinct contacts.
- Media
- RTP. Codecs offered are G.722 first, then G.711 µ-law and A-law, and the audio path runs at wideband where the far end supports it. Media-layer encryption is not part of the current version; contact Symfy if your organisation has a requirement for it.
- Incoming-call wake-up
- Apple Push Notification service (VoIP push) for iOS and Firebase Cloud Messaging for Android, triggered by the PBX through the Symfy PBX control service over HTTPS.
- Outbound access required
- TCP 5061 to the tenant SIP host, TCP 443 to the Symfy PBX control service and to Apple's or Google's push endpoints, and outbound UDP for RTP media on the range your PBX is configured for.
- IPv6
- IPv6-only networks with NAT64/DNS64 are supported.
- Platforms
- iPhone on iOS 17 or later; Android build distributed separately.
Provisioning is manual by design: extensions and their SIP passwords are created on the PBX, and the user enters them once in the app. There is no QR-code or configuration-file provisioning today.
Getting a diagnostic log from a user
The app keeps a technical SIP log on the device, behind an engineer view in Settings (tap the version row several times to reveal it). Authentication details are removed from the log before it is written, and the user can share it from that screen. Ask the user to send it along with the time of a failed call.
Transparency
Privacy and security
- The connection to your PBX uses SIP over TLS, and the server's certificate is validated against the host for your company code.
- Your SIP password is stored in the device keychain, marked so it cannot move to another device, and it is removed from diagnostic logs.
- Zubsip protects your account information, your authentication and the connection to the telephone system. For the content of a conversation itself, the current version works to the same standard as business telephone systems generally do, and it is not designed for conversations that require high-grade or end-to-end encryption.
- The app does not record calls, does not read your contacts, and contains no analytics or advertising components.
- Call history and favourites stay on your device. Your PBX keeps its own call records, and may record calls if your organisation has configured that.
We are here
Contact support
Write to us and a person will answer. Including the details below in your first message usually saves a round trip.
LINE
@symfysupport
Please include
- Zubsip app version (shown at the bottom of Settings)
- Your device model and iOS or Android version
- Your company code and extension number
- Your organisation, or the PBX provider if it is not Symfy
- Roughly when the problem happened, including the time of a failed call
- The exact error message, or a screenshot
- Which network you were on, and whether it also happens on another network
Do not send SIP passwords or other secrets by e-mail unless support specifically provides a secure method. Support does not need your password to help you.
Questions