Getting information through TCP stream graphs – the Time-Sequence (Stevens) window
by Charit Mishra, Yoram Orzach, James H Baxter
Wireshark Revealed: Essential Skills for IT Professionals
- Wireshark Revealed: Essential Skills for IT Professionals
- Table of Contents
- Wireshark Revealed: Essential Skills for IT Professionals
- Credits
- Preface
- 1. Module 1
- 1. Getting Acquainted with Wireshark
- 2. Networking for Packet Analysts
- The OSI model – why it matters
- IP networks and subnets
- Switching and routing packets
- WAN links
- Wireless networking
- Summary
- 3. Capturing All the Right Packets
- Picking the best capture point
- Test Access Ports and switch port mirroring
- Capturing interfaces, filters, and options
- Verifying a good capture
- Saving the bulk capture file
- Isolating conversations of interest
- Using the Conversations window
- Wireshark display filters
- Filter Expression Buttons
- Following TCP/UDP/SSL streams
- Marking and ignoring packets
- Saving the filtered traffic
- Summary
- 4. Configuring Wireshark
- 5. Network Protocols
- The OSI and DARPA reference models
- Transport layer protocols
- Application layer protocols
- Summary
- 6. Troubleshooting and Performance Analysis
- Troubleshooting methodology
- Troubleshooting connectivity issues
- Troubleshooting functional issues
- Performance analysis methodology
- Top five reasons for poor application performance
- Summary
- 7. Packet Analysis for Security Tasks
- 8. Command-line and Other Utilities
- 2. Module 2
- 1. Introducing Wireshark
- 2. Using Capture Filters
- 3. Using Display Filters
- 4. Using Basic Statistics Tools
- Introduction
- Using the Summary tool from the Statistics menu
- Using the Protocol Hierarchy tool from the Statistics menu
- Using the Conversations tool from the Statistics menu
- Using the Endpoints tool from the Statistics menu
- Using the HTTP tool from the Statistics menu
- Configuring Flow Graph for viewing TCP flows
- Creating IP-based statistics
- 5. Using Advanced Statistics Tools
- Introduction
- Configuring IO Graphs with filters for measuring network performance issues
- Throughput measurements with IO Graph
- Advanced IO Graph configurations with advanced Y-Axis parameters
- Getting information through TCP stream graphs – the Time-Sequence (Stevens) window
- Getting information through TCP stream graphs – the Time-Sequence (tcp-trace) window
- Getting information through TCP stream graphs – the Throughput Graph window
- Getting information through TCP stream graphs – the Round Trip Time window
- Getting information through TCP stream graphs – the Window Scaling Graph window
- 6. Using the Expert Infos Window
- 7. Ethernet, LAN Switching, and Wireless LAN
- 8. ARP and IP Analysis
- 9. UDP/TCP Analysis
- Introduction
- Configuring TCP and UDP preferences for troubleshooting
- TCP connection problems
- TCP retransmission – where do they come from and why
- Duplicate ACKs and fast retransmissions
- TCP out-of-order packet events
- TCP Zero Window, Window Full, Window Change, and other Window indicators
- TCP resets and why they happen
- 10. HTTP and DNS
- 11. Analyzing Enterprise Applications' Behavior
- Introduction
- Finding out what is running over your network
- Analyzing FTP problems
- Analyzing e-mail traffic and troubleshooting e-mail problems – POP, IMAP, and SMTP
- Analyzing MS-TS and Citrix communications problems
- Analyzing problems in the NetBIOS protocols
- Analyzing database traffic and common problems
- 12. SIP, Multimedia, and IP Telephony
- Introduction
- Using Wireshark's features for telephony and multimedia analysis
- Analyzing SIP connectivity
- Analyzing RTP/RTCP connectivity
- Troubleshooting scenarios for video and surveillance applications
- Troubleshooting scenarios for IPTV applications
- Troubleshooting scenarios for video conferencing applications
- Troubleshooting RTSP
- 13. Troubleshooting Bandwidth and Delay Problems
- 14. Understanding Network Security
- A. Links, Tools, and Reading
- 3. Module 3
- 1. Welcome to the World of Packet Analysis with Wireshark
- 2. Filtering Our Way in Wireshark
- 3. Mastering the Advanced Features of Wireshark
- 4. Inspecting Application Layer Protocols
- 5. Analyzing Transport Layer Protocols
- 6. Analyzing Traffic in Thin Air
- 7. Network Security Analysis
- 8. Troubleshooting
- 9. Introduction to Wireshark v2
- Bibliography
- Index
One of the tools in Wireshark that enables us to dig deeper into applications behavior is the TCP stream graphs. These graphs, as we will see in the following recipes, enable us to get the filling of the application behavior along with the possibility to locate problems in it.
Open an existing capture or start a new capture. Click on a specific packet in the capture file. Even though you can use this feature on a running capture, it is not meant for online statistics; so it is recommended that you start a capture, stop it, and then use this tool.
To view TCP stream graph statistics, perform the following steps:
- Click on the packet of the stream you want to monitor.
- From the Statistics menu navigate to TCP StreamGraph | Time-Sequence Graph (Stevens). The following window will open up:
The graph actually shows the advance of byte transfer over time. In this example we see a continuous diagonal line, which is an indication of a good file transfer.
To measure the throughput of a file transfer, simply calculate the bytes transferred in a unit of time as shown in the following screenshot:
We see that the transfer rate is 1,200,000 bytes in 100 seconds, that is, 12,000 bytes/seconds or 95 Kbits/sec.
- Clicking on a point in the graph using the scrollbar will magnify the graph around the point that you clicked on.
- Right-clicking on a point in the graph will take us to the packet pane in the captured file.
- For changing graph parameters, we have a small window opened parallel to the graph as shown in the following screenshot:
- For changing from zoom in to zoom out, click on the in or out button.
The Time-Sequence Graph (Stevens) is a simple graph that counts the TCP sequence numbers over time. Since TCP sequence numbers count the bytes sent by TCP, these are actually application bytes (including application headers) sent from one side to another.
This graph (as we will learn in the TCP and applications chapters) can give us a good indication of the application's behavior. For example, a diagonal line means a good file transfer, while a diagonal line with interrupts shows a problem in transfer. A diagonal line with a high gradient indicates fast data transfer, while a low gradient indicates a low rate of transfer (depends on the scale of course).
Left-clicking on a point in the graph will take you to the packet in the packet pane. When you see a problem, zoom into it, left-click on it, and check what went wrong with the packets.
While viewing a graph, it is important to know what the application is. A graph that indicates a problem in one application can be a perfect network behavior for another application.
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