Audiotrix C2, C4 & C8
Choose 2, 4 or 8 FXS ports for analog phones and small sites.
- Selection criterion
- Exact firmware and a real-world T.38 test when fax is required.
Use Case
Fax & Modem Migration
Evaluate T.38, G.711 pass-through, line conditions and service-provider behavior for fax and modem continuity.
Products to compare
A starting point for your project. Review the model data sheet before ordering.
Mediatrix 4102 / 4102S
Connect two analog endpoints to an IP voice service.
- Selection criterion
- Endpoint behavior, carrier compatibility and fax requirements.
Mediatrix C7 Series
A compact gateway for a small analog or mixed-interface installation.
- Selection criterion
- FXS versus FXO ports and the exact C7 configuration.
Mediatrix S7 / S7 LP
Bring multiple analog extensions onto an IP network.
- Selection criterion
- Line count, cabling and S7 versus S7 LP requirements.
CALL-PATH SCHEMATIC
Trace the fax & modem migration path end to end.
Every device and service is part of a live operating workflow. The diagram makes the translation point, trust boundary and acceptance target visible.
NO PUBLIC INTERNET REQUIRED
Private LAN / isolated IP network
Local phones, a local IP PBX, Mediatrix gateways and Sentinel can exchange SIP calls entirely inside the organization. The voice path can remain on a private LAN, VLAN, campus network or isolated operational network.
OPTIONAL FOR EXTERNAL SERVICES
SIP carrier, PSTN, Teams or cloud
An external connection is used only when calls must reach public numbers, remote sites or hosted services. If the required call path is entirely local, the system can stay on the private network.
ANALOG / LEGACY EQUIPMENT
Fax machine
Transmits documents using tones that must survive the complete IP path.
Analog modem
Carries data over audio and is highly sensitive to packet loss, jitter and codec changes.
Fallback voice test
Confirms basic dialing but does not prove fax or modem data integrity.
FXS / FXO / PRI / BRI
CONVERSION POINT
Mediatrix gateway
Presents the correct analog or digital interface, then converts validated traffic to SIP.
PRIVATE CUSTOMER NETWORK
PRIVATE IP NETWORK / LANLocal SIP signaling + RTP media
INTERNALLocal IP PBX / call server
Controls extensions and internal routing on the private network. It may remain fully on-premises.
Local calls stay localPhones and the on-site PBX can communicate without a public Internet connection.
OPTIONAL EXTERNAL PATH
SIP carrier
Terminates external calls and determines supported fax or modem behavior.
PBX / cloud voice
Receives calls, applies the dial plan and connects users or workflows.
Copper / TDMFXS · FXO · PRI · BRISIPRTP / T.38
READING THE DIAGRAM
A gateway replaces the line interface—not the complete service obligation
- Phone or endpoint
- Creates or receives a call. An analog endpoint needs an FXS interface; an IP phone connects directly to the data network.
- Fax or modem
- Sends data as audio. It must be tested through the complete gateway, network and carrier path—not only for dial tone.
- Mediatrix gateway
- Converts analog or digital voice interfaces into SIP/IP while preserving validated legacy equipment.
- SIP carrier
- Connects the organization to the public telephone network and supplies telephone numbers and external call routes.
Use-case model — field validation remains mandatory for endpoints, carriers and safety-related workflows.
VALIDATION MATRIX
The checks that prevent a silent failure after cutover.
A fax & modem migration design should answer each question before rollout, not after the first incident.
Safety, emergency, alarm and regulated services require approval from the responsible authority and service provider for the actual deployment.| Validation layer | Question to answer | Evidence to collect | Owner |
|---|---|---|---|
| Endpoint | Does the real device behave correctly over the new path? | Dialing, media and feature test | Customer / integrator |
| Network | Are latency, jitter, NAT and QoS controlled? | Capture and quality baseline | Network team |
| Service | Does the carrier support the required call or data behavior? | Carrier-accepted test result | Carrier / service owner |
| Failure | What happens during power, WAN or platform loss? | Failover and recovery test | Operations |
| Lifecycle | Who owns updates, certificates, backups and escalation? | Approved runbook and entitlement | Service owner |
FREQUENTLY ASKED
What to know before the next step.
The most common risk is assuming endpoint, carrier or network behavior instead of validating it in the actual call path.
Use a repeatable reference architecture, but confirm site-specific power, WAN, interfaces, endpoints, local routing and operational constraints.
The pilot should prove real workflows, not only dial tone: features, media quality, exceptional routes, failover, monitoring and recovery.
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