Methods for Measuring Network Latency Across TCP/IP Layers

Today we summarize several methods for measuring network latency at each protocol layer of the TCP/IP model.

1. Application Layer

Telnet is an application‑layer protocol used for remote login and can check the status of an IP port, but it cannot measure network latency. Custom programs could record the time difference between sending and receiving data, although the measurement may include processing overhead.

2. Transport Layer

2.1 TCPPing

The tcping command operates at the transport layer, allowing you to check both port status and ping latency, even when ICMP is blocked.

2.2 UDPPing

UDPPing works similarly to TCPPing but uses UDP packets. A Python implementation is available on GitHub (wangyu-/UDPping).

2.3 Tcproute

Tcproute is a Windows console program that performs traceroute over TCP, providing an alternative to the ICMP‑based tracert utility.

3. Network Layer

ICMP is the primary protocol of the network layer. Common tools such as ping and tracert rely on ICMP to test reachability and display the path to a destination. ICMP can only verify connectivity and round‑trip time; it cannot check port status.

MTR combines ping and traceroute functionality with a graphical interface, allowing you to view per‑hop latency and packet loss.

4. Data Link Layer

Latency at the link layer is usually measured with hardware instruments. An oscilloscope can capture the time difference between a trigger signal and the received signal on a transmission line to determine line delay.