John

GSM voice gateway channel capacity compared at 8, 16 and 32 channels: concurrency against ports, codec cost, SIM ratios, and a load test that produces numbers.

GSM cellular trunk gateway or bridge device: how to match the interface your PBX accepts, wiring checks, and why one-way audio is usually a media path fault.

4G LTE GoIP gateways: how to read 2G sunset timetables, what changes about voice, whether the price premium is worth it, and running a mixed estate.

2G and 4G USB SMS modem pools: driver and port naming, AT command differences, power sizing for batches, and why registered channel count is the metric.

What high-speed means for an SMS blast modem: the four variables that set real throughput, a repeatable test method, and how to spot a network-side limit.

Inbound call routing on GSM gateways: number mapping, one-to-many against one-to-one lines, busy and unanswered handling, and the four causes of inbound failure.

When a consumer 4G multi-WAN router is not enough: concurrency and NAT ceilings, the three signals of a limit, and how a SIM-pool gateway differs.

Scaling TGW gateways from 64 to 512 SIMs: three expansion paths, cost and operational comparison, capacity assessment, and how to support the change.

512-slot SIM banks: fault isolation by slot, safe hot-swap practice, multi-gateway topologies, and keeping a register of five hundred numbers accurate.

Using a TGW gateway as a SIP trunk endpoint: registration and authentication, number routing, failover behaviour, and a cutover acceptance checklist.