Per packet overhead on VDSL2 – part 3

Previous instalments: Per packet overhead on VDSL Per packet overhead on VDSL2 – part 2 Related Bufferbloat list thread For tonight’s edition I have increased the number of small packet sizes in the experiment and dropped the larger sizes. For each of the following data sizes (iperf -l) there are five seconds of traffic: 0, […]

Per packet overhead on VDSL2 – part 2

A few days ago I wrote about some interesting latency results I observed on my home Internet connection with small packets. This post adds a bit more data. In this experiment I disabled all upstream traffic shaping and then used iperf to blast UDP packets of various sizes to a destination host I control. The […]

Per packet overhead on VDSL2

My home router (Linux box) is configured to shape upstream traffic to just below the link rate to avoid Bufferbloat – this greatly improves interactive performance under load. Recently I’ve experimented with various packet sizes. The charts below show the effect of small packets. Between 0-6 seconds the link is idle. From 6-14 seconds the […]

IPv6 deployment day is here

A few minutes ago major Internet companies enabled IPv6 permanently. Happy IPv6 day! World IPv6 Day World IPv6 Launch The view from my server: [dan@alpha ~]$ ping6 -n -c 1; ping6 -n -c 1; ping6 -n -c 1 PING 56 data bytes 64 bytes from 2001:4860:4008:802::1012: icmp_seq=1 ttl=59 time=5.04 ms — […]

System virtualization moves the edge of the network

One of the biggest innovations of the Internet was moving the intelligence from the network to the edge devices. Making the end host responsible for data delivery and creating a network architecture that is application agnostic were radical and incredibly successful ideas. Although much of the architecture made this switch the demarcation between the network […]

Making the Linux flow classifier tunnel aware

Flow Classifier The Linux kernel has many different tools for managing traffic. One of them is the flow classifier which allows the user to configure which fields of the packet headers should be used to create a hash which is then used to identify flows and manage them. For example, if the user selects src,dst,proto,proto-src,proto-dst […]

Linux flow classifier proto-dst and TOS

Recently I’ve been playing around with the Linux flow classifier on my gateway. The flow classifier provides the ability to group network flows by configuring which parts of the packet headers (referred to as keys) are used in a hash calculation which chooses the output queue. All of my Internet traffic travels over an IPIP […]