Problem description

Current (the one working for Spring 25 release) BYON WebRTC Event Subscription is incomplete (it is useable only for particular use-case or requires some implementation consideration for the issue described below at GW). Propose to resolve this in next release (the release after Spring 25).

Facts:

• The racmSessionId field is mandatory in the WebrtcSubscriptionDetail.
• The sessionId field is also defined within WebrtcSubscriptionDetail.

Based on these facts, it is understood that prior to initiating a BYON WebRTC Event Subscription, either the BYON-RACM-Service or the BYON-CallHandling-Service must be invoked accordingly.

This raises a fundamental issue regarding call handling processes (that the call handling fails) as follows.

For example:

• As illustrated in Figure 1, the invitation notification (e.g., receiving a terminating call) appears to be unachievable until the event subscription (BYON WebRTC Event Subscription) is fully completed.

• Similarly, as shown in Figure 2, in the context of a session creation scenario, notifications for these events cannot be sent to the web client until the event subscription process is fully completed.

To resovle this fundamental issue, the basic way forward is that prior to invoking the BYON-RACM-Service or the BYON-CallHandling-Service API, a BYON WebRTC Event Subscription API needs to be invoked.

Expected behavior

Make BYON WebRTC Event Subscription complete by ressolving the issue above in next release (the release after Spring 25)

Alternative solution

To enable the BYON WebRTC Event Subscription API to be invoked before the BYON-RACM-Service or BYON-CallHandling-Service APIs, it is proposed to remove racmSessionId and sessionId from WebrtcSubscriptionDetail