How many bytes in a packet?

Sometime, we found some devices that point out "forwarding rate, Mpps". The "pps" is the short term for packet per second. However, how many bytes in a packet? It depends, there is no specification on how many byte in a packet, you define it by yourself.

In the 100M Ethernet network,
100M bps / 8 = 12.5 MBps = 12500000 Bytes/s(Bps)

If you define the frame size is 64 Bytes (Minimum Ethernet framz size):
8 Bytes (preamble) + 64 Bytes + 12 Bytes (interframe gap) = 84 Bytes

So forwarding rate will be
12500000 Bps / 84 bytes = 148809 pps

If you define the frame size is 1518 Bytes (Maximum Ethernet framz size):
8 Bytes (preamble) + 1518 Bytes + 12 Bytes (interframe gap) = 1538 Bytes

So forwarding rate will be
12500000 Bps / 1538 bytes = 8127 pps

100M Ethernet's forwarding rate formula:
12500000 Bps / ( 8 Bytes (preamble) + (Feame Size) + 12 Bytes (interframe gap)) = forwarding rate, pps

c/c++ 運算子優先順序

優先 符號                                     運算種類                         結合

---- ----------------------                   -------------                       ------

1     ( ) [ ] -> .                                運算式                             左至右

2     ! ～ ++ -- -                             (運算元) 一元運算子     右至左

        * & sizeof

3     * / %                                       乘/除/餘數                      左至右

4     + -                                           加/減                               左至右

5     << >>                                      左移/右移                       左至右

6     < <= > >=                               關係運算子                    左至右

7     == !=                                      關係運算子                    左至右

8     &                                            位元 AND                       左至右

9     ^                                             位元 XOR                       左至右

10    |                                             位元 OR                          左至右

11   &&                                         邏輯 AND                       左至右

12   ||                                             邏輯 OR                          左至右

13   ?:                                            條件運算子                    右至左

14   = += -= *= /= %=                  指定運算子                    右至左

        <<= >>= &= |= ^=

15   ,                                              循序計值                        左至右

SVN externals 屬性 依賴 外部連結

快速
http://blog.csdn.net/echoisland/article/details/6584875

詳細
https://cylin.wordpress.com/2007/10/08/svnexternals%E5%B1%AC%E6%80%A7%E4%B9%8B%E4%BD%BF%E7%94%A8/

//windows 操作
http://ccd9527.blogspot.tw/2010/06/svnexternals.html
https://help.cloudforge.com/entries/22483742-Setting-up-svn-externals

原文
http://svnbook.red-bean.com/nightly/en/svn.advanced.externals.html

linux networking netfilter

netfilter

http://blog.csdn.net/qy532846454/article/details/8255728

POCO C++

POCO code  trace

http://blog.csdn.net/arau_sh/article/details/8568674

http://blog.csdn.net/arau_sh/article/details/8568819

linux kthread

本來一個小程式打算用此寫，因此做了一些研究

做了點紀錄，雖然最後沒有用這個方式

ref.

http://blog.csdn.net/huofeng_2008/article/details/21177459

http://blog.csdn.net/wangyunqian6/article/details/6588274

http://blog.csdn.net/liuyuan_jq/article/details/6325175

http://nano-chicken.blogspot.tw/2010/01/linux-modules9-kthread.html

http://reneeciou.blogspot.tw/2013/08/linux-kernel-threads.html