This question was sent to me in an email following my posts on regarding TCP CUBIC. The answer is Yes—Microsoft Windows does support TCP CUBIC, but the nuance is in how and when it’s used. For many years, Windows defaulted to Compound TCP (CTCP) rather than CUBIC. Meanwhile, Linux distributions standardized on TCP CUBIC, which […]
Does Windows support TCP CUBIC? Read More »
I described what Adaptive Bit Rate Streaming (ABR) is in my prior article, if you need that background. Also there is an ABR Lab Exercise if you want some hands on learning with ABR that will show you visually some of the items discussed below. Here, I wanted to dive a little deeper into this
Mapping ABR to TCP Congestion Control and QUIC Read More »
Most people do not know this, but TCP CUBIC is the dominant congestion control algorithm used in modern TCP/IP networks. It is designed to efficiently utilize high-speed, long-distance links while maintaining fairness across flows with different round-trip times (RTTs). Today, it is the default congestion control algorithm in most Linux systems, and since most servers
What is TCP CUBIC and Why so popular? Read More »
In this post, I want to document the fundamental algorithms built into TCP. Keep in mind that these have changed over time in an attempt to make TCP more effective with faster and larger capacity connections of todays Internet. See our post on TCP “versions” here. TCP uses several key algorithms to manage connection setup/teardown,
In this tutorial I am going to make you a pro at using and leveraging the Wireshark TCP Graphing tools. As many of you who have taken my Wireshark Courses know, I am a big fan of visualizing what is going on in a given packet capture or conversation. My #2 troubleshooting step is to
Zero to Hero with Wireshark TCP Graphs: A Tutorial Read More »
Below is a great TCP Analysis Flags Cheat Sheet for Wireshark. These are essentially Display Filters. They are all included in our TCP troubleshooting profile you can find here. Analysis Flags/Display filter Trigger Impact/Meaning/Notes tcp.analysis.ack_lost_segment A segment that is not in the trace has been acknowledged Indicates that not all packets have been recorded or a route has been flapped tcp.analysis.duplicate_ack The receiver
Wireshark TCP Analysis Flags Cheat Sheet Read More »
So often in Wireshark videos and classes we spend a lot of time on TCP behavior. But what I am about to discuss is hardly ever brought up. The answer to version is simple right? Version 4. OK, kind of right, but overlooking too much. The truth is that there are multiple “versions” of TCP,
Which Version of TCP are you using? Read More »
I understand the argument: Since there is so much TCP (HTTP anything, etc. etc.) this is what the user experiences. That argument has several issues. First, we need to discuss the problems with using TCP at all as there are technical reasons the idea does not align with the goal of speed tests. Second, the
Why TCP Should Never be Used for Speed Tests Read More »
Check out these great references as well: Our custom profiles repository for Wireshark Our Udemy course on Wireshark Our Udemy course on Wireless Packet capture Introduced in version 3.6 and later is a new Wireshark expert analysis process called TCP Completeness. At first this was quite confusing, but once you get to know what is
Zero-to-Hero – Wireshark TCP Conversation Completeness Read More »
CellStream, Inc. – Telecom Consulting and Training! 4-Day Instructor Led Hands On Lab Class Available in either Web Based delivery or On-Site Delivery Minimum 10 students – Maximum 16 students Course Description: This is an advanced L2 Ethernet and Netmask course that leverages Wireshark and packet capture to not only visualize but to learn
CSI-HO-038 – Hands On Advanced Ethernet and Netmask Read More »
CellStream, Inc. – Telecom Consulting and Training! 1-Day Instructor Led Hands On Lab Class Available in either Web Based delivery or On-Site Delivery Minimum 8 students – Maximum 16 students What Students are saying about this class: “[The instructor] explains things in a way that any of us can understand.” “Seeing scenarios first hand. Knowing
CSI-HO-020-J – Wireshark TCP Analysis in a Day – 1 Day Read More »
Let’s say you deal with HUGE packet captures and you need to parse or carve out certain types of packets or conversations from the source. This is particularly true for folks that use Ring Buffers, or folks who do huge captures over long time period with fast interfaces. If you do this you start to
Carving and Parsing Packet Captures Read More »
As most of us know, a key to managing the Internet is knowledge of TCP and UDP port numbers. Cisco IOS uses Access Control Lists for many purposes, but in this tip, we will focus on TCP and UDP port numbers. Port numbers are unique, well-known, registered or ephemeral numbers used by TCP (Transmission Control
UDP and TCP Port Number Usage in ACL’s in Cisco IOS Read More »
Most network engineers and technicians are quickly discovering that with “everything over IP” we are required to understand exactly what this means. For a lot of the standard, traditional data communications between clients and servers this means transport over TCP. Furthermore, it requires the ability to troubleshoot TCP. To troubleshoot TCP you have
A Wireshark TCP Troubleshooting Configuration Profile Read More »
CellStream, Inc. – Telecom Consulting and Training! 2-Day Instructor Led Hands On Lab Class Available in either Web Based delivery or On-Site Delivery Minimum 10 students – Maximum 20 students What Students are Saying about This Class: “Andrew is a great instructor. I thoroughly enjoyed the Wireshark for Data
CSI-HO-020-B – Explore Packet Analysis with Wireshark – Data Center Edition – 2 Day Read More »
