The gateway cut, without pretending to be the CUBE guide · Worked example
Write the border
Two columns: what the Five9 PDF says, and what you still must confirm on the gateway.
- Four PDF facts
- Three open gateway questions
The second column is labeled unconfirmed.
- INVITE failures? Check both sides.
- Extensions as DNIS? Do not assume it.
- 20 ms? Uncertain practitioner note.
- SRV? Preferred on the Five9 side.
Sources and go deeper
- Technical requirements PDF. vendor. last checked 2026-10. Fetched for this lab in October 2026. Re-read before you buy hardware or open a firewall.
- SIP trunk options chapter. vendor. last checked 2026-10.
- RFC 3261. rfc. last checked 2026-10.
- RFC 3550, RTP. rfc. last checked 2026-10.
- RFC 3551, RTP profile for audio and video. rfc. last checked 2026-10.
- ITU-T G.711. standard. last checked 2026-10.
- RFC 8446, TLS 1.3. rfc. last checked 2026-10.
- RFC 1035, domain names. rfc. last checked 2026-10.
- RFC 2782, DNS SRV. rfc. last checked 2026-10.
- ITU-T E.164, international public telecommunication numbering. standard. last checked 2026-10.
- RFC 1918, private internet addresses. rfc. last checked 2026-10.
- RFC 4787, NAT behavior for UDP. rfc. last checked 2026-10.
- confirm. NANP versus E.164, 20 ms ptime, and 'no internal extensions' are practitioner cautions. They are not quoted here as Five9 requirements. last checked 2026-10.