我不认为你所描述的是可能的。在B2B呼叫中，呼叫的所有SIP流量都通过UCMA应用程序（充当背对背用户代理）传递。如果该应用服务器发生故障，两个远程端点无法互相重建通信
- 从他们的角度来看，他们正在通话的端点已经消失，即使媒体可以继续流动，因为它正在进行直接在两个远程端点之间。

I don't think what you're describing is possible. In a B2B call, all of the SIP traffic for a call is passed through the UCMA application (which acts as the back-to-back user agent). If that app server fails, the two remote endpoints have no way of re-establishing communication with each other - from their perspective, the endpoint they were talking to is gone, even though the media can continue flowing because it is going directly between the two remote endpoints.

你可以（有点）拥有一个UCMA应用程序的另一个实例"接管"使用呼叫替换（INVITE with Replaces）进行背对背呼叫，您可以在管理B2B呼叫的实例未能查看
是否有效之后立即测试，但我怀疑它是否可靠。可能值得一试，具体取决于你需要这个功能的程度。

You CAN (sort of) have another instance of a UCMA application "take over" a back-to-back call using call replacement (INVITE with Replaces), and you could test doing this right after the instance managing the B2B call has failed to see if that works, but I doubt it would be reliable. Might be worth a try depending on how badly you need this functionality.

如果你需要更多细节，请告诉我。

Let me know if you need more details.