Building the SureVoIP App. Gavin Henry, SureVoIP, Trusted UK VoIP service provider. Founder and MD TADSummit EMEA Americas 2020 Gavin Henry will take you through all the components that were needed to build the SureVoIP app. Using the power of Flutter, one source code base can be used to power mobile, web and desktop app versions. The journey covers key open source projects created, enhancements to existing open source projects, adoption of open source building blocks with standards based technologies like OAuth2, PKCE, AppAuth, PushKit, CallKit, OpenSIPS, RFC8599, Biometrics, RESTful APIs, WebSockets, SIP, Push Notifications, FreeSWITCH, WebRTC and many more. Gavin Henry is the founder of SureVoIP, an Internet Telephony Service Provider and has written most of the software that sticks it all together. His interests include all aspects of software engineering, identity management (especially around OpenLDAP), all layers of the network stack, systems programming and the free software ecosystem. Gavin has an engineering degree in Electronics and Communications and outside of software has a real passion for the field of bushcraft. He can be reached at ghenry@surevoip.co.uk or https://twitter.com/ghenry Listen to some of his podcasts which also discuss key technologies used with leading industry security experts – https://www.se-radio.net/team/gavin-henry/

1. Who am I?
• Gavin Henry, 42
• Father of Ben and Husband of Laura
(Co-Director)
• Full time in own business
since 2005
• Open Source project
contributor, then consultant
and then ITSP/SaaS
• Software Engineer
• SE Radio Podcast Host

2. What are my current services
• Hosted VoIP
• SIP Trunks
• SIP DDIs
• OSS PBX support
• Internet (Broadband and Ethernet)
• Hardware and provisioning

3. Our network

5. Tech
●
Flutter – natively compiled apps for
mobile, web and desktop
●
Firebase Cloud Messaging for Push
and PushKit on iOS
●
Flutter Secure Storage
●
SureVoIP API
●
SureVoIP Portal
●
Wiredash.io and Sentry.io

6. Tech (contd)
●
AppAuth / OAuth2 / Ory Hydra
●
OpenLDAP
●
OpenSIPS 3.1 with RFC8599
●
FreeSWITCH
• SIP over WebSockets with WebRTC
• Dart SIP – jsSIP port to Dart
• Open source -
https://github.com/cloudwebrtc/dart-
sip-ua

7. Difficulties
●
VoIP libraries are new (we
sponsored) as are PushKit and
CallKit related ones
●
Background messages with FCM
●
RFC8599 in reality for inbound calls
●
App stores and business model / IAP
●
CI/CD on GitHub
●
App state management choices – we
use GetX for all
●
Animations on iOS

8. Contribute!
• Dart SIP – jsSIP port to Dart
• Open source -
https://github.com/cloudwebrtc/dart-
sip-ua