I don’t understand what a SIP invite is. Certainly it’s explained as:
“This article explains the main fields included in a SIP INVITE, which is sent to set-up a VoIP call. A SIP INVITE message contains typically between
4 and 6 header entries with contact information inside them.”
The article enumerates the headers and explains them. But what sends the invite? Asterisk? A soft-phone?
I found sample config’s to send an invite with Asterisk but no other method was given. Can only Asterisk send an invite? Why? The article says that it’s sent “to set-up a VoIP call,” so presumably any reasonable soft-phone sends these invites as a normal process.
That’s all well and good, but how do send an actual invite and get a response? This can only be done through Asterisk?
This is in the context of:
Requires IP Authentication to be setup through the portal and associated with LRN under Telephone Data
Send a SIP Invite to *lrnlookup.telnyx.com *
with the number you wish to dip on port 5060
The response will be a SIP 302 redirect for example:
SIP/2.0 302 Moved Temporarily Via: SIP/2.0/UDP
CSeq: 1 INVITE
Contact: Transfer <5555555555>
If a number has been ported the response will contain the dip indicator
(“npdi;”) as well as the LRN (rn=+1..), otherwise these fields will be missing
and then clicking “Data API” and then “SIP request” for details.
I have a running instance of Asterisk. I would have to handle the invite through Asterisk and keep it running to make and receive calls? Presumably this invite is interacting with Asterisk, or something similar, at telnyx.com — which seems overkill.