API-first networking considerations for IT leaders

What is API-first networking?

In API-first networking, engineers use APIs to build, operate and manage the entire network. It's not like traditional networks, where the function is built around a GUI or CLI and the API is bolted on afterward to expose functionality or to connect to external systems.

Instead, APIs become the central control plane of the entire enterprise network infrastructure. With API-first networks, teams can program a variety of functions, including the following:

• Network provisioning.
• Network configuration.
• Policing.
• Telemetry.
• Network automation.
• Network updates based on current needs.
• Network management.
• Network troubleshooting.
• Integration with multi-cloud providers, vendors and enterprise processes.

API-first networks are designed before deployment. For IT leaders in compliance-heavy and critical industries, domain-specific custom workflows can be used to reflect their specific needs.

The governance benefit for IT leaders is that APIs operate in a client-server model, backed by well-defined contracts. Every network function becomes a versioned agreement within a request that returns a defined response. This means that compliance can be checked before the API-based network function is executed.

Similar to microservices, API-first networks are composable. Each network operation and asset is exposed as consistent, independent, reusable and scalable API blocks. This approach can lead to too many decoupled services. Network infrastructure comprised of multiple vendors can also experience downtime if an API fails.

API-first networking benefits

Enterprises use API-first networks to build architectures that are both flexible and secure, combining zero-trust security with adaptability. At the same time, individual developers are building newer networking services and products as open source. This ensures faster time to market and sets the stage for apps with better CX and UX for both customers and clients.

Key advantages of API-first networking include the following:

Programmability

A programmable network operates 360 degrees through software, compared to a hardware-dependent traditional network. In other words, API-first networks become addressable by code. Network functionalities get exposed through model-driven interfaces and structured data models. Programmable networks support multi-tenancy. Each tenant, whether an internal team member, vendor or third-party member, can securely access the network slice.

Automation

Networking shifts from CLI commands to pipelines. APIs serve as a translation layer, exposing multiple network operations through tokens and role-based controls. IT leaders can onboard internal teams, even without technical expertise, to manage API-first networks, thus reducing complexity and the networking team's operational workload.

Assume a router's configuration no longer matches approved values. API-first network monitoring deploys an automated pipeline to confirm differences, implement resets and compare against policy frameworks. Compliance is less of a problem as well, because administrators can discover errors during implementation. The automated pipeline logs the entire incident in the files rather than causing an outage.

System integration

API networking exposes backend network functionality through consistent interfaces that can be integrated in end-to-end enterprise workflows, continuous integration/continuous delivery deployment pipelines, monitoring dashboards and orchestration platforms. API networks define functions through common schemas, rather than different formats.

As a result, network data becomes readable by various enterprise applications and analytics platforms, making it accessible throughout IT operations. The API networking payoff becomes a unified toolchain and observability stack.

Evaluate API-first vendor platforms

When APIs went mainstream, vendors redesigned their flagship offerings from command-wrapping interfaces to model-driven control for handling network code. Engineers oversee API-network functions as infrastructure as code across third parties, the same approach used to manage code in configuration files. To that end, choose vendors that support network automation tools such as Ansible and DevOps tools such as Terraform.

Cisco, for example, anchors part of its networking strategy on the intent API, a northbound REST API built on standard HTTP requests and JSON-encoded data. The platform lets IT leaders determine how they want the network to perform as a part of their business policies.

Arista centers its programmability approach through its extensible operating system (EOS), which is programmable via JSON API (eAPI) and the vendor-neutral data model OpenConfig. Some IT leaders prefer vendor-neutral platforms to prevent lock-in. Juniper Apstra, the intent-based networking platform, lets companies build networks sourced from multiple suppliers.

Run pilot projects with various vendors for different business functions to help you select the right partner. Don't overlook AI agents; bots are becoming the latest network operators. Design your API-first network to be agent-friendly.

API-first networking considerations

While greenfield enterprises and startups can quickly build and deploy API-first networks, organizations with legacy networks must take the time to rethink their operating models. Begin by evaluating existing network infrastructure and vendors before going API-first.

Considerations for API-first networking include the following:

API documentation

Select API network partners with detailed documentation. Documentations should include instructions in the following:

• Machine-readable format.
• Endpoints.
• Tokens.
• Requests.
• Responses.
• Authentication methods.
• Error codes.
• Fixations.
• Policies.

Slightly more than half of developers struggle with inconsistent documentation, according to the Postman survey. Run trial-and-error before the API enters production. Consider API contracts with clear versioning, policies and change logs in addition to documentation and software development kits.

Interoperability requirements

Choose API vendors that support open standards and model-driven interfaces to facilitate cross-vendor integration. Consider network as a service providers and vendor-neutral platforms. APIs are dynamic, enabling vendors to constantly push updates, add new features and change capabilities. Choose APIs that offer backward compatibility to avoid downtime.

Performance implications

API rate limits reject extra connections beyond a threshold and within a specified time frame. Understand API rate limits to plan volume requests. Break large network jobs into small batches, and roll out large backend changes gradually to ensure optimal performance.

Security

When network functions are exposed as control, security threats grow. Adopt security frameworks that include strong authentication and authorization at endpoints and API gateways, API usage limits, role-based access control, least privilege and audit trails. Centrally define permissions in the API contract, rather than at entry points of different devices.

Any changes to permissions are a policy review, rather than a network operator decision. In API access control, defining endpoints for the pipeline through security contracts prohibits the API pipeline from entering beyond the set boundary.

Venus Kohli is an engineer turned technical content writer, having completed a degree in electronics and telecommunication at Mumbai University in 2019. Kohli writes for various tech and media companies on topics related to semiconductors, electronics, networking, programming, quantum physics and more.