Catalog
concept#Architecture#Software Engineering#Integration#Security

TCP/IP Model

A conceptual layered model describing network functions and protocols for IP‑based communication.

The TCP/IP model is a conceptual framework that defines a layered architecture for internetworking and communication protocols used across IP‑based systems.
Established
Medium

Classification

  • Medium
  • Technical
  • Architectural
  • Intermediate

Technical context

Network monitoring (e.g., Prometheus, SNMP)Configuration management (e.g., Ansible)Security tools (IDS/IPS, firewalls)

Principles & goals

Clearly separate layers, define responsibilitiesProtocols should be interoperable and minimalFacilitate fault localization along layers
Build
Enterprise, Domain, Team

Use cases & scenarios

Compromises

  • Lack of clear boundaries causes responsibility issues
  • Incorrect layer assignment hinders debugging
  • Overreliance on the model can overlook security gaps
  • Document layer mapping for services
  • Use standardized protocols and versions
  • Regular checks of network parameters and SLAs

I/O & resources

  • Topology and configuration data
  • Security and compliance requirements
  • Measurement data from monitoring systems
  • Layer‑specific architectural decisions
  • Recommendations for protocols and controls
  • Test and operational procedures

Description

The TCP/IP model is a conceptual framework that defines a layered architecture for internetworking and communication protocols used across IP‑based systems. It abstracts network functions into four layers with clear responsibilities, guiding protocol design, interoperability, deployment and systematic troubleshooting across implementations and vendors.

✔

  • Promotes interoperability between vendors
  • Enables modular protocol development
  • Supports systematic troubleshooting

✖

  • Abstraction may hide implementation details
  • Not all modern protocols map neatly to four layers
  • Neglects physical‑layer specific peculiarities

  • Packet loss

    Proportion of lost packets over a period; indicator of network reliability.

  • Latency (Round‑Trip Time)

    Time for a message round trip; relevant for performance‑critical applications.

  • Throughput

    Amount of data transmitted per time unit; measures capacity and efficiency.

IPv4 routing between two data centers

Use of IP routing (network layer) and BGP to connect heterogeneous network segments.

TLS for web applications

TLS is layered on transport‑layer services (TCP) to protect application data.

NAT in hybrid cloud scenarios

Network Address Translation operates at the network layer and affects addressing and debugging.

1

Inventory of current network architecture

2

Map services to TCP/IP layers

3

Define controls, tests and monitoring

⚠️ Technical debt & bottlenecks

  • Outdated protocol versions in critical paths
  • Insufficiently documented network topology
  • Hardcoded addressing and lack of automation
Routing convergenceMTU and fragmentationDNS resolution
  • Applying transport optimizations without interoperability tests
  • Implementing security controls only at the application layer
  • Changing MTU without end‑to‑end validation
  • False assumptions about transparent NAT behavior
  • Mixing transport and application perspectives in diagnostics
  • Underestimating DNS impact on availability
Knowledge of network protocols and OSI/TCP‑IPTroubleshooting and metrics collectionSecurity and segmentation principles
Interoperability between systemsScalability of networks and servicesSecurity and segmentation requirements
  • • Dependence on standard protocols and RFCs
  • • Legacy infrastructure with proprietary peculiarities
  • • Physical constraints (bandwidth, latency)