Sylk Pushserver
Sylk Pushserver was designed to act as a central dispatcher for mobile push notifications inside RTC provider infrastructures. Both the provider and the mobile application customer, in the case of a shared infrastructure, can easily audit problems related to the processing of push notifications.
Deployment scenarios
Sylk Pushserver can be deployed together with WebRTC server applications or VoIP servers like SIP Proxies and PBXs. Its main purpose is to act as a central entity inside RTC provider infrastructures. Without such a component, the same functionality must be built inside multiple servers and as the number of mobile applications increases, the need for such central component becomes obvious.
Design
Sylk Pushserver can handle an arbitrary number of different combinations of push notification service and mobile applications. It and can be extended by using Python programming language to support new push notification services and applications. Sample applications are provided to handle Sylk and Linphone mobile applications for Apple and Firebase push notification services.
For each configured Apple application, the server maintains a persistent connection by using HTTP/2 over TLS 1.2 and reuses that connection for sending notifications related to the application. Latest voip functionality for iOS 13 or later is also suported.
Each outgoing connection can use its own set of credentials, X.509 certificates and urls. The connection failures are properly handled and incoming requests remained queued for later by using a timer dependent on the payload type.
For more information see the release notes here:
https://lists.ag-projects.com/pipermail/sipbeyondvoip/2020-June/003458.html