![=[ x25-box.com ]=](http://www.x25-box.com/wp-content/themes/pixeled/images/rss-trans.png){kind=small}
Packet Switching and X.25 Networks. Page 14
Fig 1.11 Example ofa layer two conversation with wrap-around of the sequence number
receiver the FCS is incorrect and the whole frame is discarded without
further attention. This is normally done by the hardware
What happens in these circumstances is that the righthand side will issue a Reject frame. This is done on receipt of an out-of-sequence frame—in this case number five—and will indicate where retransmission is to start. In this case we require frame 4 to be retransmitted. However, all subsequent frames will also be retransmitted as the receiver will ignore frames following the one that was out-of-sequence. The conversation would therefore continue as shown in Fig. 1.13.
Fig. 1.12 Loss of frames in transit; note that it is unusual to lose the whole frame; normally it is corrupted, thus has a bad FCS and is therefore ignored by the hardware and not passed to layer two
-
-----------------------------------------------------
Welcome to =[ x25-box.com ]=
блог проекта x25-box. Обсуждение сетей x25, tcp/ip. wifi, security research, hacking,
Новостная лента RSS.
-----------------------------------------------------
---------------[ Donation Bar ]---------------
- Как сюда попасть
- www.x25.com.ru(4$)
- Poker Room(3.5$)
- Lechenie zavisimostey(3.2$)
- aikibudo(3$)
- www.25.net.ru(2.5$)
-----------------------------------------------------
Packet Switching and X.25 Networks
[ статистика ]
