I hope to realize a scenario as follows. Several users register with the same SIP ID. When someone calls the SIP ID, all the users will receive the INVITE request. Such SIP forking is supported by OpenSIPS. However, in my scenario, we have some users registering via iOS app. Thus, these users may be in the iOS background mode. In this case, they are unable to register and I need to employ APNS to try to let these users in the iOS foreground mode.
Consider some users are already online and some are in the iOS background mode. SIP forking will send INVITE to only the online users and will not send to those users who register after entering iOS foreground mode from iOS background mode. In other words, SIP forking will not send INVITE to those users registering with the same SIP later than the INVITE was received by the SIP server.
Has anyone encounter any issue like this? Any comment is greatly appreciated.