How to handle 400 calls and bind sip calls?

Hello, I suggest you don't adopt this scheme in the future. Let me tell you the following shortcomings that hinder your large-scale promotion.

1, SIP docking mode is to use VOIP as the answering scheme. Although this is a new technical scheme, it is illegal and may be closed by operators at any time.

2. Besides image, the core of 400 aims is to improve service quality. How to ensure the call quality of VoIP?

Anyway, if you want to bind the SIP phone with 400, you need to point the 400 phone to a platform built by the destination phone, and then the platform will do SIP docking and guide it to your seat. The telephone platform must have an independent IP, otherwise it is normal to get through.