Behind every "virtual number" that actually receives SMS and calls sits physical equipment: a GoIP GSM gateway and a Simpool SIM bank. This is the bridge between the cellular network and the internet. Genuine SIM cards from real mobile carriers are inserted into the gateway, and you receive the signal over IP. Let's break down how this infrastructure works, how GoIP differs from Simpool, and why physical SIMs specifically deliver high deliverability.

GoIP: the GSM gateway as the foundation

GoIP is a hardware GSM gateway that converts the voice and signaling of a cellular network into IP traffic (SIP/RTP). Essentially it is a device with several GSM modems, each of which takes a SIM card. When a call or SMS arrives at that SIM's number, the gateway catches it on the radio module and sends it over the network to a server.

What GoIP does

  • Registers the SIM in the carrier's network: each SIM becomes a full subscriber with a real IMSI.
  • Receives SMS: inbound messages are read from the modem and passed into the system.
  • Receives calls: voice is encapsulated into SIP and routed to a SIP client or PBX.
  • Connects over IP: management and traffic go through the internet.

Models differ by the number of channels — for example GoIP-8 for 8 SIMs or GoIP-32 for 32 SIMs. The more channels, the more numbers a single device serves.

Simpool: the SIM bank

When numbers reach the hundreds and thousands, keeping all SIMs directly in the GSM gateways becomes impractical. This is where Simpool comes in — a separate SIM bank that stores large arrays of SIMs and, on demand, "feeds" the needed card into the gateway's radio channel.

Why separate the SIM from the radio module

Simpool physically separates SIM storage from the GSM modems. This provides flexibility: the same SIM can be connected to different radio channels, cards can be rotated, and a large fleet can be managed centrally. For the infrastructure operator this means scaling without a linear growth in the number of gateways.

  • Centralized storage: hundreds of SIMs in one bank.
  • Flexible binding: a SIM is fed to the right modem by the system's logic.
  • Fleet management: a single control point for each card's status.

How it all assembles into a "farm"

A GoIP farm is a bundle of many GSM gateways and Simpool SIM banks combined into a single management system. The server tracks every line: which SIM is active, what its number is, which carrier, which country, whether the line is busy or free. When a client takes a number, the system allocates a specific physical line and delivers inbound SMS and calls over IP.

Layers of the farm

  • Hardware: GoIP gateways and Simpool banks with real SIMs.
  • Transport: an IP channel to the management server.
  • Logic: line accounting, SMS/call routing, number allocation.
  • Catalog: 17 countries, different carriers, landline and mobile numbers.

Why a physical-SIM farm beats purely software solutions

The main advantage is deliverability. To the network and to anti-fraud systems, a number on a physical SIM is indistinguishable from an ordinary subscriber: a real IMSI, a real mobile range, a real network registration. That is why such numbers receive service SMS and pass verifications where purely software VoIP numbers are blocked. Plus both SMS and calls arrive on one number.

Practical consequences

  • High SMS deliverability: for short codes and service messages.
  • Call support: voice verification and inbound calls.
  • Geography: real carriers across 17 countries for the right scenario.

Frequently asked questions

How does GoIP differ from Simpool?

GoIP is a GSM gateway with radio modems that catches the network signal and delivers it over IP. Simpool is a SIM bank that stores an array of SIMs and feeds the needed card into the radio channel. Together they form a scalable farm.

Are these real SIM cards or emulation?

These are genuine physical SIMs from real mobile carriers. The network sees them as ordinary subscribers with a real IMSI, so they receive SMS and calls natively.

How many numbers does one farm serve?

It depends on the number of gateways and the capacity of the Simpool banks. A bundle of many GoIP-32 units and SIM banks scales to thousands of lines across dozens of countries.

To get a real-carrier number from a GoIP/Simpool farm for receiving SMS and calls, choose a country in the turbon.rent OTP activations catalog, and for a stable, private network channel add turbon.rent mobile proxies.