Snom M900 multicell DECT base

Size the radio system per occupied area

The M900 is a managed multicell DECT base, not a Wi-Fi access point or a SIP desk phone. Snom documents large theoretical system limits, but each base has its own simultaneous-call limit: up to eight narrowband or four wideband calls in multicell operation. Use the per-base figure, user concentration and call pattern when planning capacity.

A maximum system count does not establish how many bases a building needs. Survey the occupied site and model corridors, lifts, stairwells, fire doors, shelving and other attenuation before fixing locations.

Choose and verify synchronization

Snom lists both DECT and LAN synchronization, with IEEE 1588 for the LAN method. Record which method the design uses and its network prerequisites. Confirm the synchronization tree and handover behavior while a call moves between cells; registration at a desk is not a roaming acceptance test.

Keep the DECT manager role, configuration backup and replacement procedure in the operating plan. A base outage, synchronization failure and SIP-registration failure need separate alarms and recovery checks.

Separate standard and optional codecs

The manufacturer lists G.722, G.711 and G.726 in the base specification. It lists G.729, BV32 and Opus under the optional A900 accessory. Do not copy those optional formats into the base record as standard capability. Confirm the installed license or accessory, PBX policy and per-base wideband capacity before enabling a format.

Test the exact handset and intended PBX in both narrowband and wideband scenarios. A codec listing does not establish end-to-end negotiation or measured voice quality.

Validate network, provisioning and lifecycle

Confirm the exact EU or US DECT part number, local spectrum plan, PoE budget, VLAN, addressing, time source and certificate trust. The product page documents TLS 1.2 and mutual-TLS provisioning, but those protections require matching services and operational ownership.

Pilot base replacement, configuration restore, handset update and rollback in a maintenance window. Obtain current regional stock, approved firmware and support dates from Snom or an authorized partner; a current catalogue page is not an inventory or remaining-support guarantee.

Choose M400 dual cell or M900 multicell deliberately

The M400 reference covers one- or two-base deployments and codec-dependent capacity for that bounded topology. Keep M900 multicell scale, synchronization, base density and firmware evidence separate; a shared handset family does not make the base architectures interchangeable.