Keep Zoom Phone, the carrier and the SBC separate
BYOC-P keeps Zoom Phone's cloud PBX features while the organization retains a chosen PSTN carrier and operates a supported session border controller. Zoom's Route Groups and SIP Groups describe the cloud-side relationship; the carrier order, number service, access and SBC-to-carrier handoff remain separate. BYOC-P is not a generic claim that any trunk or SBC combination will interoperate.
Record the Zoom account region and licenses, carrier order, number inventory, exact supported SBC model and software, interfaces, public addresses, certificates and owners. Zoom says carrier coverage determines the BYOC-P service area, so a Zoom region or data center does not establish number availability or site serviceability.
Documented service facts
Reviewed 2026-10-09. Compare SIP trunk services →
SIP authentication
DocumentedInternet peering uses mutual TLS between Zoom and the customer SBC. Zoom requires a public certificate from a supported CA, Server Authentication key usage, the complete chain and the SBC FQDN in CN or SAN; the current infrastructure page also says Zoom does not perform expected-hostname peer-name validation on the customer SBC certificate. Keep certificate trust, presented identity, private-key custody, permitted source addresses and carrier-side authentication as distinct controls.
SIP registration
Not verifiedThe reviewed BYOC-P documents describe provisioned SBCs, Route Groups and SIP Groups rather than a phone-style REGISTER workflow. Do not invent a registrar, Contact expiry or registration indicator. Confirm the current account's provisioned peers, certificate state, OPTIONS or other health evidence where configured, and an actual authorized transaction independently.
Inbound delivery
DocumentedInbound PSTN calls traverse the selected carrier and customer SBC, then the BYOC-P Route Group and SIP Group to a Zoom destination mapped by DID or extension. BYOC-P requires the Request-URI user to contain the destination E.164 number. Carrier activation, Zoom number inventory, SIP Group mapping, identity acceptance and final user or service outcome remain separate checkpoints.
Routing and failover
DocumentedZoom supports regional trunks to customer SBCs and Internet or private-circuit connectivity. Internet calls may route to an alternate Zoom data center within the region. Those platform choices do not establish customer SBC high availability, carrier rerouting, access diversity, route priority, detection timers, restoration order or established-call survival. Document every Zoom, customer and carrier failure domain and test only the accepted design.
Number and regional availability
DocumentedZoom states that BYOC-P service areas are determined by the customer's chosen telephony provider. Zoom account region, SIP-zone assignment, regulatory eligibility, carrier coverage, number inventory, portability and site address remain separate orderability records. A Zoom data-center presence is not proof that a carrier number or route is available at a requested location.
Audio codecs and DTMF
DocumentedThe current infrastructure requirements list Opus, G.722, G.711 mu-law, G.711 A-law and G.729, RFC 2833 DTMF and mandatory Early Offer for INVITEs sent to Zoom. This is an interface capability list, not proof of one call's offer, answer, selected codec, digits or quality. Preserve both Zoom-facing and carrier-facing SDP and any SBC translation.
T.38 fax
Not verifiedThe reviewed BYOC-P architecture, infrastructure and call-processing pages do not establish one universal T.38 or G.711 fax profile, switchover sequence, redundancy model or completed-page result. Qualify the carrier, SBC, Zoom license or endpoint, gateway, number, direction, document set and fallback without transferring a voice codec list into fax support.
Signaling and media encryption
DocumentedZoom says Internet peering uses TLS 1.2 and SRTP between the customer SBC and Zoom. Private-circuit design and the carrier-facing leg retain their own protection profiles. Mutual certificate exchange does not prove expected-hostname matching, media selection or complete-path encryption, so record the exact TLS session, certificate chain, SDP and packet path on each leg.
Concurrent calls and call starts
Not verifiedThe reviewed sources do not publish a universal BYOC-P simultaneous-call entitlement, calls-per-second limit or carrier burst policy. Size Zoom licensing, carrier channels, Route and SIP Groups, SBC sessions and transcodes, access bandwidth, firewall state and emergency reserves separately; a reachable trunk does not establish accepted load.
Emergency calling
DocumentedZoom lets administrators select Zoom or the third-party carrier as the target for emergency calls by BYOC numbers. BYOC addresses can require carrier confirmation, and ERL/ELIN designs may depend on outgoing caller ID. Number presence, confirmed address, detected location, route, callback, internal notification, outage behavior and approved non-live validation remain separate evidence.
Pricing model
Not verifiedBYOC-P retains the chosen carrier and a customer-provided SBC while using Zoom Phone licensing. The reviewed documents do not establish a universal current total or itemized BYOC-P price. Obtain dated Zoom, carrier, SBC, private-circuit, number, emergency, messaging, support, tax and implementation terms for the exact countries and sites.
Administration and support
DocumentedZoom administrators provision SBCs, Route Groups and SIP Groups, then map routing and numbers in the web portal. Customer teams still own the supported SBC, certificates, firewall, dial plan, carrier interconnect and evidence. Assign separate Zoom, carrier, SBC, network, number, emergency, monitoring, escalation and rollback owners before cutover.
SMS and MMS
DocumentedZoom documents optional native SMS and MMS activation for eligible US and Canada BYOC numbers, with number-level activation, an LOA and applicable 10DLC registration. It excludes several categories including US/Canada toll-free and wireless numbers and non-US/Canada BYOC numbers in the reviewed workflow. Voice routing through BYOC-P does not prove messaging eligibility or activation.
Build the Zoom-facing trunk from current portal evidence
Provision SBCs inside Route Groups and Route Groups inside SIP Groups, then use the portal values for the exact account cluster. Internet peering requires bidirectional firewall paths; Zoom's current infrastructure page publishes a different media range from ordinary Zoom client traffic. Do not copy addresses or ports from another cluster, region or old deployment.
Treat object creation, certificate validation, transport establishment, health signaling, accepted INVITE and completed call as separate states. The reviewed documents do not define a phone-style REGISTER requirement, so an absent registration lamp is not by itself evidence that this fixed peering model is down.
Preserve the mutual-TLS and media boundaries
For Internet peering, Zoom documents TLS 1.2 and SRTP. The customer SBC certificate must come from a supported public CA, carry Server Authentication usage, present the complete chain and include the SBC FQDN in CN or SAN. The same page says Zoom's mutual-TLS implementation does not compare that identity with an expected peer hostname.
Do not turn certificate exchange into proof of authorization, an accepted SIP transaction or end-to-end encryption. Retain firewall source policy, chain validation, key custody and monitoring as additional controls. Record the carrier-facing signaling and media profile independently because the Zoom-to-SBC protection does not extend automatically through the SBC.
Normalize BYOC-P PSTN calls to E.164
Zoom requires BYOC-P SIP trunks to send and receive E.164 strings. Inbound BYOC calls use the Request-URI user for the destination E.164 number, while Zoom destinations are mapped through SIP Groups and number assignments. BYOP-P private extension dialing is a different hybrid-PBX feature and should not be used to justify private numbering on the BYOC-P PSTN route.
Trace the carrier-delivered number, SBC normalization, Request-URI, asserted identity, SIP Group, assigned destination and final outcome. For outbound calls, keep calling-number ownership, selected route and carrier acceptance separate. A correct E.164 string does not prove number assignment, caller-ID authorization or media.
Treat codec support and Early Offer as negotiation inputs
Zoom's current requirements list Opus, G.722, G.711 mu-law, G.711 A-law and G.729, RFC 2833 DTMF, and mandatory Early Offer for INVITEs sent to Zoom. Record both legs of the SBC because the carrier and Zoom sides can use different codecs, packetization or media addresses.
A capability list is not an answer. Preserve the actual offer and answer, selected codec, DTMF payload, SRTP profile and observed packets. Qualify fax separately; the reviewed BYOC-P pages do not establish a universal T.38 or pass-through result.
Design resilience, emergency service and messaging explicitly
Regional Zoom trunks, alternate Zoom data-center routing, multiple customer SBCs, carrier rerouting and private access are different resilience controls. Record route priority, health signal, timer, capacity, established-call behavior and restoration at every boundary. None protects an untested single customer firewall, SBC, circuit, carrier route or number assignment.
Emergency calls may target Zoom or the third-party carrier. BYOC address confirmation, ERL or ELIN, caller identity, dispatchable location, callback and notifications require an accepted operating record. SMS and MMS are a separate Zoom-provided activation for eligible US and Canada BYOC numbers with LOA and campaign obligations; voice success does not prove messaging. No account, trunk, call, emergency workflow or message was tested for this guide.
Sources & applicability
Primary references for the technical details above. Operational examples and planning checklists are VoIP.info editorial guidance.
- Zoom Phone BYOC-P architecture ↗
- BYOC-P deployment and connectivity options ↗
- BYOC-P infrastructure requirements ↗
- BYOC-P call processing ↗
- BYOC-P configuration guide ↗
- Zoom Phone BYOC-P dial-plan management ↗
- Zoom Phone emergency addresses ↗
- Zoom Phone emergency-call routing ↗
- Zoom Phone SMS for BYOC numbers ↗
Examples require adaptation to your topology. No live PBX or hardware testing is claimed.