Trunks-incoming and outgoing sections?

we fill outgoing field in trunks for sip provider. I can understand this situation. But why we fill incoming field?
Forexample Trunk-Sip Setting-incoming sub menu, there is a text near “Register String” label:
510:[email protected]/510
Why do we type like this information for trunk?

Very often you don’t need to fill in the incoming settings for a trunk. With a registration string and the correct outgoing trunk setting (inc. the context for calls which is really an incoming call setting) that should be enough very often.

It also helps to think of those three entries (incoming settings, outgoing settings, and registration) as separate but related (to the trunk) sections.

The point of the incoming section is to route your calls and validate the systems that are connecting to your PBX. Registration is the same, but in the opposite direction.

You identify the people you are talking to for Internet VOIP Services with the outbound section. You identify the people that are servicing your phone number and sending you calls with in Incoming section. If either of those things require registration, you fill in the registration information.

So incoming section for my clients, and outgoing section is for my VoIP provider? If my system is middle of between clients and VoIP providers so my system should be behave like a bridge. So I indicate incoming and outgoing, am I right?

@the_passerby

No.

In your trunk configuration Incoming section, you specify how your VOIP provider will send Dialed Calls to your PBX.

Your clients will connect via “extensions” that connect via Chan-SIP and PJ_SIP.

It’s all about the trunk in the trunk configuration. They are normally point-to-point.