Identify the selected interconnect and service products
Magrathea publishes voice connectivity, MagSIPConnect, SIP Resilience, Secure RTP, numbering, porting and emergency handling as distinct capabilities. Record the legal account, current order, platform or PBX, assigned numbers, inbound destinations, outbound entitlement, resilience option, security option, emergency scope and support level before applying a configuration.
Do not combine product descriptions into one assumed trunk template. A hosted-platform outbound path, an inbound nominated-IP pool and an optional protected-media service can have different activation, routing and acceptance evidence.
Documented service facts
Reviewed 2026-10-12. Compare SIP trunk services →
SIP authentication
DocumentedFor MagSIPConnect, Magrathea documents a two-stage hosted-platform validation model using the provider platform IP ranges plus a unique SIP header. That is a product-specific outbound-routing statement, not proof that every Magrathea interconnect uses the same header, credential or source policy. Preserve the selected service, approved ranges, required header name and value, observed request and acceptance result without publishing secrets.
SIP registration
Not verifiedThe reviewed public pages do not define a REGISTER requirement, registrar, expiry, Contact policy or digest challenge for the selected service. MagSIPConnect describes source-range and header validation, while SIP Resilience describes nominated delivery IPs; neither statement establishes a universal registration model. Obtain current order-specific signaling details and retain DNS, transport, source, destination, Contact and response evidence.
Inbound delivery and number format
DocumentedMagrathea offers UK and Irish numbers with IP or PSTN termination to client servers, and its SIP Resilience service sends incoming calls to a nominated pool of IP addresses. The reviewed pages do not publish the exact Request-URI, identity headers, port or number format for a selected order. Preserve the assigned number, destination pool, actual INVITE and PBX match.
Inbound resilience and load distribution
DocumentedMagrathea says SIP Resilience lets the client nominate several IP addresses, probes each address several times a minute, removes an address from the pool when a failure is detected and returns it when it responds again. The page does not define the probe method, threshold, call-distribution algorithm, active-call behavior or exact restoration timing. Confirm those boundaries for the selected service and test only approved new calls.
Number and regional availability
DocumentedMagrathea advertises UK and Irish numbering, real-time number selection and provisioning through an API, plus UK and Irish porting support. Catalogue coverage does not prove that one number is available, portable, activated or eligible for a particular user and location. Preserve a dated inventory result, port validation, order and activation record.
Audio codecs, RTP and DTMF
Not verifiedThe reviewed public service pages do not publish a complete codec, packetization, RTP source, DTMF or transcoding contract for the selected voice service. Secure RTP is a separate product capability. Verify both SDP bodies, both RTP directions, negotiated payloads, decoded audio and digits on authorized non-emergency calls before changing codec or firewall policy.
Fax and T.38
Not verifiedThe reviewed pages do not establish G.711 fax, T.38, redundancy, error correction or supported gateway combinations. Qualify the exact fax direction, endpoint, negotiated SDP and document result independently; do not infer fax support from voice connectivity or Secure RTP availability.
Signaling and media protection
DocumentedMagrathea offers a Secure RTP product that uses TLS for SIP signaling and SRTP for audio. Treat this as an available product boundary, not an automatic property of every trunk. Confirm entitlement, transport, certificate validation, SRTP profile, keying, provider source ranges and downgrade behavior for the selected order. The unique MagSIPConnect header is an authorization input, not encryption.
Concurrent calls and call-start rate
Not verifiedThe reviewed public pages do not publish a selected concurrency, calls-per-second ceiling, burst policy, per-destination capacity or load-test allowance. Obtain written limits and an approved test plan before generating traffic; a resilient pool or managed route does not establish capacity.
Emergency calling
DocumentedMagrathea offers UK and Ireland 999/112 handling. Its page requires the provider to submit the customer name and normal-location address, describes software integration, a short testing period, and handling of both the call and location data. Confirm the selected order, registered address, callback identity, change process, power and access dependencies, accessible alternative and provider-approved validation procedure; never place an uncoordinated emergency call.
Pricing and contract
Not verifiedThe emergency page describes tiered usage pricing, but the reviewed public pages do not establish current setup, number, porting, inbound, outbound, resilience, encryption, support, tax, minimum-spend or termination charges for a selected order. The website terms also say site material may change without notice. Preserve a dated quote, service schedule, rate deck, billing increments, taxes, credit terms and cancellation treatment.
Administration and support
DocumentedMagrathea describes real-time number control through an API and a support team for fault resolution and regulatory procedures. SIP Resilience adds provider-side health handling for nominated addresses. The reviewed pages do not establish the selected portal fields, API schema, support entitlement, response time or restoration result. Retain current account documentation, escalation contacts, timestamps and provider case identifiers.
SMS and MMS
Not verifiedThe reviewed voice, numbering and connectivity pages do not establish SMS or MMS eligibility, sender registration, inbound routing, throughput, retention or price for a selected number. Qualify messaging as a separate product and regulatory workflow rather than inferring it from voice numbering.
Scope MagSIPConnect validation to hosted outbound traffic
Magrathea says MagSIPConnect validates hosted-platform traffic in two stages: provider IP ranges and a unique SIP header. Preserve the approved range set, required header, source observed at the provider boundary and response for one authorized call. Protect header values as credentials and confirm how changes are coordinated.
This product page does not establish a universal REGISTER, digest-authentication or inbound-delivery model. Do not add registration or substitute a broad source allowlist unless the selected service documentation requires it.
Bind inbound numbers to the nominated resilience pool
Magrathea offers UK and Irish numbers with IP or PSTN termination, while SIP Resilience sends incoming calls to nominated IP addresses. Preserve the affected number, active destination list, expected PBX or SBC at each address, current DNS and routing, actual Request-URI and identity headers, and the application route selected after delivery.
The public page describes provider probes and pool membership but does not publish the probe protocol, exact threshold or distribution algorithm. Treat a responding address, a pool member, an INVITE arrival and an accepted PBX route as separate states.
Keep optional TLS and SRTP separate from authentication
Magrathea describes Secure RTP as a product using TLS for SIP signaling and SRTP for audio. Confirm that the selected order includes it, then preserve the offered transport, certificate chain and name validation, negotiated SRTP profile, keying, both SDP bodies and protected media result.
MagSIPConnect source-range and header validation does not encrypt signaling or media. Conversely, a TLS connection does not prove the unique header was accepted, the right number was routed or both parties decoded audio.
Treat emergency access as a location-data workflow
Magrathea says its UK and Ireland emergency service requires customer name and normal-location address submission, supports software integration and has a short testing period before 999/112 calling is available. Preserve the applicable order, service address, callback identity, data-submission result, change procedure, provider acceptance and an accessible alternative route.
Follow a provider-approved test procedure and never place an uncoordinated emergency call. IP reachability, ordinary outbound calling and a populated address field do not independently prove emergency activation or correct location presentation.
Close the undocumented operational and commercial gaps
Obtain current order-specific values for registration, URI and identity format, signaling destinations, ports, codecs, RTP sources, DTMF, fax, capacity, call-start rate, resilience details, security entitlement, support and maintenance. Keep messaging separate unless it is expressly ordered and documented.
Preserve a dated quote, rate deck, billing increments, taxes, credit terms, support schedule and cancellation treatment. Build an acceptance matrix for inbound and outbound routing, identity, audio, digits, protected media where ordered, pool removal, pool restoration and rollback. Record observed results without converting catalogue statements into laboratory validation.
Sources & applicability
Primary references for the technical details above. Operational examples and planning checklists are VoIP.info editorial guidance.
- Magrathea Voice Connectivity ↗
- Magrathea MagSIPConnect ↗
- Magrathea SIP resilience ↗
- Magrathea Secure RTP ↗
- Magrathea Emergency Services ↗
- Magrathea Numbering in the UK & Ireland ↗
- Magrathea Number Porting in the UK & Ireland ↗
- Magrathea website terms and conditions ↗
Examples require adaptation to your topology. No live PBX or hardware testing is claimed.