Migrating from chan_sip to pjsip

Colleagues, please tell me how to correctly avoid a conflict between chan_sip and pjsip?

Do I definitely need to do unload => chan_sip?
Or can it be somehow different?

Ogogon.

Why would you want both?

(You could bind them to different ports, or interfaces, or even, possibly, transports.)

You can have them both loaded.
To avoid conflicts chansip and pjsip need to differ in at least one of the following:
Bind IP address, bind port and protocol (TCP or UDP).

In other words you could e.g. have pjsip bind to port 5060 and chansip bind to port 5160 or use tcp for chansip and udp for pjsip or have a different IP address for each etc.