Streamlining eSIM IoT Validation: How Simartis Uses AMARI Callbox for more efficient SGP.32 Testing
As IoT deployments scale across regions, operators, and regulatory domains, remote subscription management under new GSMA SGP.32 standard becomes a strategic control layer — not just a new eSIM provisioning mechanism.
At Simartis, ensuring our eIM and SM-DP+ infrastructure performs predictably under real-world IoT constraints requires controlled, reproducible and realistic test environments. This is where Amarisoft and its AMARI Callbox “network-in-a-box” equipment provides the necessary capabilities that enable us efficiently running relevant, lab-validated testing.
IoT eSIM Testing Challenges
eSIM deployments in IoT world introduce more complexities compared with those encountered in Consumer scenarios:
- Constrained NB-IoT and LTE-M devices
- Multi-IMSI strategies for roaming control
- Bootstrap-to-operational profile transitions
- Fallback and rollback mechanisms
- NTN or degraded radio conditions
Under SGP.32, the eIM, through is central role in the standard architecture, must orchestrate all of this, most of the time without direct human interaction. Validating these functions through traditional live network testing, however, is often time-consuming, unpredictable and costly.
eSIM Testing with Callbox: Device-Centric Workflows
Testing of eSIM IoT starts at the development boards and module evaluation stage, where firmware, radio stacks, and hardware integrations are still evolving. These early environments allow direct observation of radio behavior, IMSI selection logic, and eUICC interactions under varying firmware conditions.
Validating SGP.32 eIM functions at this stage helps detect integration inconsistencies early, before devices reach mass production.
The Callbox provides a quick-to-set-up and reproducible network environment, enabling controlled execution of end-to-end eSIM workflows across multiple access technologies. Within this setup, we validate:
- Successful initial attach through the eSIM Provisioning profile
- eSIM installation and activation steps for Operational profile
- PLMN attach and detach behavior based on profile configuration
- APN configuration for IP-data
- Log collection to verify eSIM profile successful activation and network attach.
These validations ensure that eSIM IoT systems behave predictably, even when scenarios are complicated by device constraints or roaming dynamics.
Multi-IMSI Validation through Multi-PLMN environment
The AMARI Callbox configuration we are using can emulate multiple PLMNs simultaneously, enabling us to generate realistic multi-operator environments. This allows us testing more efficiently the logic of the complex, Multi-IMSI profiles for continuous and optimized connectivity purposes when deployed in the field.
Under SGP.32, IoT devices may still make us of multiple IMSIs within the same eSIM profile enabling businesses implement various network preference strategies, optimize roaming costs, while meeting regulatory compliance.
Using Callbox, we can reproduce scenarios where devices:
- Select different IMSIs depending on available PLMNs
- Switch profiles based on network and device events
- Validate fallback attributes under operational conditions
Lab validation of these scenarios is a key milestone before scaling into production.
NB-IoT, LTE-M and Constrained Radio Validation
Unlike smartphones, which typically rely on high-bandwidth LTE or 5G networks, IoT devices operate on purpose-built access technologies such as NB-IoT and LTE-M. These IoT-specific radio technologies are optimized for low power consumption, extended coverage, deep indoor penetration, and reduced data throughput — characteristics essential for smart metering, asset tracking, environmental sensing, and other large-scale deployments.
Because of these constraints, eSIM lifecycle operations must function reliably under conditions very different from traditional mobile broadband environments.
AMARI Callbox enables Simartis to configure and exercise NB-IoT-only deployments and LTE-M scenarios, including constrained uplink capacity, controlled latency, and limited bandwidth conditions. This allows us to reproduce real IoT radio environments in a deterministic and repeatable way.
This enables validation of:
- Direct and Indirect profile download, including rollback mechanism
- Fallback profile prioritization logic
- Retry policies under constrained connectivity
This controlled validation ensures that eSIM lifecycle management works reliably under the real IoT radio conditions devices will face in production.
From Lab Validation to Field Confidence
Simartis eSIM IoT solution is set to deliver centralized lifecycle control under new SGP.32 standard. But architecture alone is not enough — without validation, it must be proven.
By leveraging the Amarisoft Callbox, we ensure that:
- Constrained IoT network scenarios are thoroughly exercised in varied setups
- Multi-IMSI switching logic is fully controlled and verified
- Profile installation, including rollback and fallback mechanisms are validated
In deployments spanning millions of devices and multiple operator domains, predictable behavior is non-negotiable. Lab validation bridges the gap between standards compliance and operational confidence.
Before devices ever reach the field, their lifecycle behavior must already be validated under realistic conditions.
That is how trust is engineered into eSIM IoT from day one.
