Migration
The gateway cut, without pretending to be the CUBE guide
A teaching bridge: skills, modules, modes, data, the gateway, and a go/no-go that can stop.
From UCCX and UCCE ยท advanced ยท 12 min full read
When the third SIP story is a Cisco gateway, the technical requirements are still the Five9 side: DNS SRV preferred, G.711 as the default codec, TLS 1.2, no double NAT. What the gateway itself must rewrite โ number format, a normalization script, early media โ lives in Cisco's documentation.
- Keep Five9 requirements and gateway chores in two columns
- Do not cite a Cisco example as a Five9 default
Practitioner notes often mention G.711 at 20 ms, NANP versus E.164, and 'do not send internal extensions.' Treat every one of those as uncertain until the trunk guide you and the carrier signed actually says them. RFC 3261 tells you what an INVITE is. It does not choose your dial plan.
Do not let one document speak for the other.
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.
- 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.
Glossary. IVR module: A named block in the IVR Administrator's Guide, such as Menu, Play, If/Else, or Skill Transfer. IVR modules
Sister technologies. Zoom Phone and Microsoft Teams. Named prebuilt connections. A local UC client is also about 320 kbps. APIs and SDKs
Config. Two columns: what the Five9 PDF says, and what you still must confirm on the gateway.
Troubleshooting. The gateway is sending a private plan the DNIS table does not contain. Fix the called number, with the gateway guide open.
Cross-platform bridge. A mapping to another PBX or contact center is a teaching bridge. It is not an import button.
Future hook. The guide's cloud endpoint stays unset. Confirm before relying on a dated catalog or a case-study number.