Networking Sequence Diagrams

The sequence diagrams were generated using EventStudio System Designer.

Working from a packet capture of your own? VisualEther turns a Wireshark PCAP into a sequence diagram like these — TCP, HTTP, TLS, BGP, OSPF, Kerberos and more — then lets Claude Code explain what failed, with frame numbers.

IP - Internet Protocol

IP Routing and Subnets

This article describes the basics of IP routing. We will consider the example of a simple network and trace the life of a packet as it gets routed from one node to another.

ICMP Sequence Diagram

Ping is a popular application used to check the presence of another node. Ping uses the ICMP Echo and Echo Reply handshake message for this purpose

ARP Sequence Diagram

ARP (Address Resolution Protocol) is responsible for mapping from IP addresses to MAC address on Ethernet.

DHCP Sequence Diagram

Dynamic Host Configuration Protocol (DHCP) is used to dynamically provide IP addresses and configuration information to client nodes.

DHCP Flow with Message Details

Simple DHCP based IP address allocation with message level details. Click on individual messages in the flow to see field level details.

IGMP Query, Group Join and Group Leave Flow

IGMP is used by routers and hosts to management multicast group membership. This sequence diagram describes IGMP query, join and leave with a sample flow that was captured with Wireshark.

NFS Sequence Diagram

This sequence diagram describes mounting, opening and reading of a file via the NFS (Network File System).

BOOTP Sequence Diagram

The Bootstrap Protocol (BOOTP) enables a host to boot from ROM and request it's own IP address, a gateway address and a boot file name. The boot file is used to load the disk image into RAM.

TCP - Transmission Control Protocol

TCP Sequence Diagrams

Protocol sequence diagrams that describe the following features. Each feature is described with client and server side interactions called out separately.

  • 3-way handshake setup and release of a TCP connection.
  • Analyse slow start congestion control mechanisms built right into TCP.
  • The primary objective of congestion avoidance is to maintain high throughput without causing congestion.
  • Fast retransmit and recovery detect a segment loss via duplicate acknowledgements.

HTTP Sequence Diagrams

HTTP Sequence Diagram

HTTP sequence diagram for loading of the EventHelix.com home page. The page load is captured in two threads. The sequence diagrams for individual threads are also included.

Web Caching and Refresh Sequence Diagram

This sequence diagram tutorial describes the web caching feature on the web browser side. HTTP primitives that facilitate the implementation of web browser level caching are shown using an example.

Web Page Redirection Sequence Diagram

The interactions involved in web page redirection using HTTP 302 code are covered here.

HTTP Post Sequence Diagram

HTTP Post handling and lower level TCP interactions are shown in this diagram.

TCP Applications

FTP Sequence Diagram

Here we explore the sequence of interactions in a typical FTP (File Transfer Protocol) session. Individual sequence diagrams for interactions on Port 20 and 21 are also included.

Telnet Sequence Diagram

Telnet sequence covers terminal option negotiation and server handling.

SMTP E-Mail

Sequence diagram describing SMTP e-mail send. DNS MX record interactions are also covered.

POP3 Sequence Diagram

Interactions between a POP3 server and client are described here.

HTTPS SSL/TLS Session for SPDY Message Flow

This sequence diagram covers the establishment of a SSL/TLS connection for sending Google SPDY data. Diffie-Hellman handshake with Elliptic Curve cryptography are also covered.

SSL Sequence Diagram

Message sequence diagram describing the setup of a SSL secure connection.

IKEv2 IPSec VPN Sequence Diagram

Learn how IKEv2 is used to setup the VPN. Explore how the IPSec headers are added and removed from the VPN tunnel.
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LDAP Sequence Diagram

Lightweight Directory Access Protocol (LDAP) message flow that describes Kerberos authentication and directory access.

IP Routing Protocols

BGP Router Startup

The sequence of interactions at the startup of a Border Gateway Protocol (BGP) router are described here.

BGP Router Peering and Route Update

Learn about the BGP message interactions in router peering and route updates. Click on any message in the sequence diagram to see field level details.

OSPF Router Startup

This flow shows the message exchange that takes place when a new OSPF router comes online. You can click on any message in the flow to see full message contents.