Deep dive into Kernel

Packet drop is recorded in only Port level. (GLPRT_RDPC)GLV_RDPC is drop from no usable descriptor ring buffer.

USB Configuration Device DescriptorsThe device descriptor of a USB device represents the entire device. As a result a USB device can only have one device descriptor. It specifies some basic, yet important information about the device such as the supported USB version, maximum packet size, vendor and product IDs and the number of possible configurations the device can have. The format of the devi..

OUT : Host computer --> USB deviceIN : USB device --> Host computer USB endpoint 의 종류 CONTROL : (Asynchronous) control endpoint 는 USB device에 access하기 위해서 사용됨 예를 들어 configure device, retrieving information from device, sending command to the device, retrieving status reports about the device 모든 USB device 는 CONTROL에 해당하는 "endpoint 0"를 가짐 USB device가 insert 될 때 사용됨 guaranteed by the USB protocol ..

USB Device Creation Process

Q35 USB initialization - Create PCI device and initialize it as USB Host Controller (uhci or ehci) EHCI Controller Reference: [1] Enhanced Host Controller Interface Specification for Universal Serial Bushttp://www.intel.co.kr/content/dam/www/public/us/en/documents/technical-specifications/ehci-specification-for-usb.pdf [2] USB in a NutShell : http://www.beyondlogic.org/usbnutshell/usb2.shtml [3]..

netflow capture daemon nfcapd -l /tmp -p 2055 분석nfdump -r /tmp/

http://people.netfilter.org/hawk/presentations/nfws2014/dp-accel-10G-challenge.pdf Wirespeed smallest frame Sgine CPU core Ethernet specific (20 bytes)- 12 bytes = inter-frame gap- 8 bytes = MAC preamble Ethernet frame (64 bytes)- 14 bytes = MAC header- 46 bytes = Minimum payload size- 4 bytes = Ethernet CRC => Minimum size Ethernet frame is 84 bytes (20 + 64) Peak packet rate: 14,880,952 pps= 1..

Install git clone https://github.com/Pktgen/Pktgen-DPDK.gitcd Pktgen-DPDK/dpdkexport RTE_SDK=/root/Pktgen-DPDK/dpdkexport RTE_TARGET=x86_64-pktgen-linuxapp-gccmake install T=x86_64-pktgen-linuxapp-gcc apt-get install libpcap-dev cd examples/pktgenmake Execution./app/build/pktgen -c 7 -n 4 -- -p 3 -m "1.0, 2.1" -T black Destination MAC change Format: set mac Pktgen> set mac 0 42:34:9e:c4:48:23 Ch..