On top of the telephony you already own.
CodeB isn’t pitched as another Zoom alternative — that market is crowded. We sit in a narrower niche: the browser meetings + browser-phone layer for organisations whose calls can’t leave their building. Keep your PBX (FreePBX, Asterisk, FRITZ!Box, hosted ITSP — anything SIP). Keep your trunk. Add CodeB for video, click-to-call, signed recordings, and a desk-phone-in-the-browser. Below: side-by-side with the cloud tools we’re most often compared to, with the gaps spelled out. If you’re evaluating against a CPaaS vendor specifically (Twilio, Vonage, Plivo), see the self-hosted CPaaS positioning.
Skip the matrix → Top 10 buyer reasons
CodeB isn’t a phone-system replacement.
CodeB is the meeting tool — a privacy-first alternative to Zoom and Teams — that integrates with the phone system you already run. Keep your existing PBX (FreePBX, Asterisk, a residential router, a hosted ITSP — anything that speaks SIP); CodeB sits alongside it and extends what it can do: browser video, signed recordings, click-to-call from any web page, and a PWA desk phone that ties the two together. The right framing isn’t “us versus your PBX” — it’s “us alongside your PBX, instead of Zoom or Teams.”
The Metadata Exposure Trap
Even when a cloud provider promises end-to-end voice encryption, the metadata — who called whom, when, from where, for how long — is harvested, analysed and stored in foreign jurisdictions. Often reachable under the US CLOUD Act. Encryption of content does not cure exposure of pattern. CodeB keeps both the media and the metadata inside your perimeter — NIS2, DORA and the EU AI Act (transparency rules active from August 2026) are easier to defend when the data never left the building.
Capability matrix
| Dimension | CodeB | Zoom | Microsoft Teams |
|---|---|---|---|
| Deployment | Self-host on-prem; air-gappable | Cloud SaaS only | Cloud SaaS (Microsoft 365) |
| Media routing | Peer-to-peer mesh, encrypted end-to-end | SFU via vendor cloud | SFU via vendor cloud |
| Participants per call | ~6 (mesh ceiling) | Up to 100–1000+ | Up to 300–1000+ |
| Native desktop / mobile apps | None — browser / PWA only | Win, macOS, Linux, iOS, Android | Win, macOS, iOS, Android |
| Installable desk-phone | Yes — PWA, auto-updates | Add-on (Zoom Phone) | Add-on (Teams Phone) |
| PSTN dial-out / dial-in | Built-in, BYO SIP trunk | Paid add-on (Zoom Phone) | Paid add-on (Teams Phone) |
| Mid-call “invite someone by phone” | Built-in — uses your existing trunk | Requires Zoom Phone add-on | Requires Teams Phone add-on |
| Click-to-call widget for public websites | Built-in (one-line script) | No | No |
| Telemetry / analytics | None | Vendor-managed cloud telemetry / admin analytics | Vendor-managed cloud telemetry / admin analytics |
| Data residency | Your data centre | US-centric | M365 region |
| Calendar integration (Outlook / standard formats) | .ics download — no live sync | Native | Native (M365) |
| Forensic-grade signed recording | Yes (ECDSA-P256 sidecar) | No | No |
| Recording-consent gate | Per-participant, signed | Banner only | Banner only |
| Click-to-call from any web page | Built-in (embed widget + alias) | No | No |
| AI voice receptionist (inbound) | Built-in — Live Voice AI, per-vnum persona | No | Limited (Teams Premium Copilot) |
| Outbound AI calling campaigns | Built-in — 15 use cases, live monitor | No | No |
| Per-number AI personas (virtual numbers) | Yes — prompt-based persona per DID | No | No |
| Built-in OIDC identity provider | Yes — RS256 per-tenant, PKCE-only | Identity client only | Coupled to Entra ID |
| PAI / RPID outbound caller-ID signing | Yes — per-trunk PAI / RPID / From | Carrier-managed (Zoom Phone) | Carrier-managed (Teams Phone) |
| Anonymous / CLIR caller routing | Yes — RFC 3323 + Privacy-header detect | No | No |
| Air-gap / offline deployable | Yes | No | No |
Feature comparison based on public product documentation as of June 2026. Cloud vendors evolve quickly — check the current vendor pages before making a procurement decision.
Genuinely unique to CodeB
Most rows above show "CodeB has it too, also others." A few features go the other way — CodeB has them in a shape we don’t see in the alternatives. Worth calling these out explicitly because they’re the genuine differentiators, not just rebadged table-stakes:
Voice AI receptionist + outbound AI campaigns on your own SIP trunks
Inbound: every DID can run a Live Voice AI with a per-number prompt — book appointments, transfer to a human, switch languages mid-call. Outbound: schedule one call or batches, retry on no-answer / busy, watch progress in the live monitor, persist queues across server restarts. Both directions run over your existing SIP trunks — no per-minute uplift, no third-party calling vendor, transcript emailed per call. See 15 worked use-cases. Zoom and Teams require Premium / Copilot add-ons for partial equivalents.
Self-hosted OpenID Connect identity provider
CodeB ships its own OIDC IdP — RS256 with per-tenant keys, PKCE-only by default, admin pages accept either an OIDC bearer or a HMAC-signed admin secret. Wire Nextcloud, WordPress, GitLab, Grafana, anything that speaks OIDC against it. Identity stays on your server. The other three are OIDC relying parties at best (Teams is welded to Entra ID); none of them lets you BE the identity provider.
Signed outbound caller-ID (PAI / RPID / From) per trunk
When the bridge places an outbound call, you can sign the call with the caller’s real identity via P-Asserted-Identity, Remote-Party-ID, or the From URI — per trunk, per route. Useful when a carrier requires PAI assertion for trusted-number presentation, or when you want a hospital’s main switchboard number to show up on outbound AI reminders rather than a random DID. Cloud-phone products use whatever caller-ID their carrier negotiated for you; CodeB lets you pick header by header.
Anonymous-caller routing by Privacy header
The bridge sniffs inbound INVITEs for RFC 3323 Privacy: tokens, sip:anonymous@anonymous.invalid From URIs, and common UA markers (Withheld, Restricted, Private, Blocked). A single row in inbound routing — FromNumber=anonymous, Did=* — sends all CLIR / withheld callers to whichever destination you pick (a screener AI on a virtual number is the obvious one). None of the cloud alternatives even surface this signal.
PSTN integrated into the meeting tool — without a separate telephony product
Inviting a phone number to an ongoing meeting (or dialing out to add a participant mid-call) is technically possible in Zoom and Teams — but only after buying Zoom Phone or Teams Phone, separate paid products that bundle their own carrier service. With CodeB it’s part of the base meeting tool, pointed at whatever SIP trunk you already use for company calls. No extra license, no extra vendor, no per-minute uplift beyond the trunk you already pay for.
Mid-conference “add a phone” button using your own trunk
While a meeting is going on, anyone in the room can press Dial phone, type a number, and the SIP bridge calls them into the room as a participant. They appear as a tile alongside the video peers, audio bridged in. Useful when an unscheduled person needs to be pulled into a discussion — no need to rejoin, no need to switch tools.
Click-to-call embed widget → conference room → PSTN dial-out
Drop a single <script> tag on any web page. A visitor clicks the floating button, lands in a fresh CodeB meeting room, and the SIP bridge calls your team’s phone. The visitor and the answering phone now share a private meeting. The visitor’s page never sees the real phone number (it’s referenced by an unguessable alias). Built-in — no separate live-chat product needed.
The full combination, in one self-hostable bundle
Peer-to-peer end-to-end encrypted meetings + bring-your-own SIP trunk for inbound & outbound PSTN + mid-call PSTN add + click-to-call embedding + forensic-signed recordings + on-prem / air-gap deployable. Each individual piece exists somewhere else in some form; the combination in a single open product that runs on your own Windows Server is what we haven’t seen elsewhere.
Forensic-grade signed recordings — including PSTN participants
Every recording (whether all participants are browsers, or some are bridged-in phone calls) ships with a sidecar JSON containing the file SHA-256, an ECDSA-P256 signature, the participants list, a speaker-turn timeline, and a per-participant consent log. Tamper-evident, audit-ready, and applies just as much to a call where Sarah dialed in from a mobile as to one where everyone joined from a laptop.
Unguessable alias-based dial numbers
Every callable destination has an unguessable 64-bit alias (e.g. n_dbbe66524a5cd792). Public URLs and embed widgets reference the alias, never the real number. A scraper crawling your site sees nothing it can use; to change which phone receives clicks you edit one config line server-side.
Where CodeB genuinely wins (broader strengths)
Privacy posture you can prove
Peer-to-peer media with end-to-end DTLS-SRTP encryption means your video never traverses our infrastructure — or anyone’s, in the on-prem case. A security team can verify this by reading the source. Zoom and Teams require trust; CodeB lets you check.
Truly air-gap deployable
Zoom and Teams are cloud SaaS products and need internet connectivity to operate. CodeB will run inside a fully disconnected LAN once installed — useful for defence, healthcare, regulated finance, and any environment where data leaving the perimeter is unacceptable.
The desk phone that installs in seconds
CodeB Phone is a PWA — users install it from their browser, no IT ticket, no MSI deployment. Updates self-deliver on the next reload, so the version running on every user’s machine stays current without any rollout planning.
Forensic-grade signed recordings
Every recording ships with an ECDSA-P256-signed sidecar JSON: file hash, participants list, speaker-turn timeline, and a per-peer consent log. Tamper-evident, audit-ready. Useful for healthcare consultations, legal calls, regulated-finance discussions — categories none of the other three target.
Bring your own everything
Bring your own SIP trunk, your own TURN relay, your own domain, your own TLS cert. No vendor lock-in. Your call records belong to your trunk provider. Switching trunks is a config edit, not a migration project.
Zero analytics, zero telemetry
No usage pings home, no third-party analytics, no event tracking. The privacy story isn’t just policy — nothing in the call path phones a vendor, and the access logs are yours alone.
Operator-grade ops surface
FraudGuard daily caps + per-IP rate limits + admin reset button; live outbound monitor with cancel + delete; atomic-write persistence for scheduled jobs that survives a server restart; inbound routing editable from the browser with self-healing catchall; per-tenant logs and CDRs on disk in plain CSV. Built for operators who actually have to run the thing.
Multi-tenant by domain — one binary, many tenants
Every per-tenant artefact (settings, prompts, logs, OIDC keys, SIP credentials) is keyed off the request domain. One CodeB install can host phone.example.com, phone.partner.de, conf.charity.org — each with its own users, its own AI personas, its own trunks — on the same Windows Server, no per-tenant container, no licence-per-seat.
Where CodeB genuinely loses
Worth being explicit about so you can disqualify us early if these are dealbreakers:
Scale ceiling around six participants
Mesh topology means each browser sends to every other browser — bandwidth grows with the square of participants. A 30-person all-hands isn’t practical. Zoom and Teams use a media server (SFU) and scale to hundreds.
No live calendar sync
We offer .ics download — works everywhere — but no Outlook plugin, no calendar add-on, no "join via room" sync. Teams in particular is deeply integrated with M365 calendars; we’re not.
Smaller ecosystem
Teams has thousands of third-party integrations. Zoom has a marketplace. CodeB has webhooks-on-demand and a source tree you can extend yourself. Different shape of "extensibility" — better for some teams, worse for others.
Smaller mobile experience
iOS Safari restricts PWA capabilities intentionally. We work, but with rough edges — no install prompt, limited notifications, no real background. If your team is mostly on phones, the native apps from the alternatives are a better experience today.
Who each tool fits best
CodeB Sovereign Communications
Small-to-mid teams that need a meeting tool plus a desk phone, value privacy and on-prem control over scale and cloud features, and are willing to trade large-meeting ceiling for a clean privacy story. Defence, healthcare, legal, regulated finance, sovereignty-conscious public sector, small consultancies.
Zoom
Organisations that need to host large meetings (50+) regularly, want a polished cross-platform native-app experience, and don’t have a strong "data must stay on-prem" requirement. The standard if scale and reliability are the top criteria.
Microsoft Teams
Organisations already deep in the M365 ecosystem — calendar, files, identity, chat, meetings — that want everything in one stack and don’t mind the cloud-coupling. Best if persistent channels and calendar integration are core to how your team works.
Choose CodeB if…
- You can’t (or won’t) put your meeting audio on a vendor cloud
- Your meetings are usually under six participants
- You want a desk-phone experience without deploying a heavy client to every workstation
- You have a SIP trunk or PBX already and want to integrate with it rather than replace it
- You want a voice-AI receptionist answering DIDs without sending caller audio to a third-party calling vendor
- You want to run outbound AI campaigns (reminders, surveys, follow-ups) over your own trunks
- You want to BE the identity provider (OIDC, RS256, PKCE) for your other internal apps, not just consume one
- Your carrier requires PAI / RPID outbound caller-ID assertion
- You need recordings to stand up as legal evidence (signed sidecars)
- You want to embed click-to-call on a public website without exposing a real phone number
- You operate inside a regulated environment (defence, healthcare, finance, public sector)
- You value being able to read every line of code that runs in the call path
Choose something else if…
- You regularly need to host 20+ person meetings
- Your team lives in Outlook / M365 calendar and wants tight integration
- Your team operates entirely from mobile devices
- You need extensive third-party integrations / marketplace apps
This page reflects our honest read of the alternatives as of writing. Their feature sets evolve; if you spot something out of date please let us know. The matrix doesn’t mention licensing terms or commercial models — for those, see each vendor’s own site. Marketing terms like "best-in-class" are unavoidable in a comparison page; treat them as relative ordering rather than absolute claims.