T3
Numbers and trunks
E.164, DID, and the private and public domains. 3 lessons. Each lesson cites the pages that were opened, and marks the rest confirm.
E.164 numbers and direct inward dial
T3-R07
Wikipedia says E.164 is the ITU-T recommendation titled The international public telecommunication numbering plan.
Two domains and a SIP trunk
T3-R08
Wikipedia says SIP trunking is how Internet telephony service providers deliver telephone services to customers with a SIP-based IP-PBX.
How a guide tells you to get a number
T3-R09
Telnyx's first-message guide says to buy two numbers so you can test messaging between them without registration requirements.
Sources and go deeper
Opened 2026-10. A row marked confirm has no link, because that page was not verified.
- RFC. RFC 3261, SIP last checked 2026-10
- Wikipedia. Session Initiation Protocol last checked 2026-10
- Wikipedia. Platform as a service, Communications platform as a service section last checked 2026-10
- Confirm. Release-specific menus for this track. confirm. Not opened as a single checklist. last checked 2026-10