- 校時(SYNC)
-
802.3 MAC frame format
-
untagged
- Topic
- preamble
- SFD(start of frame delimiter)
- DA(destination address)
- SA(source address)
-
T/L(type/length)
- <1500:length
- >1500:type
- DATA(46~1500byte)
-
FCS(frame check sequence)
- 錯誤檢查碼
-
tagged
- Vlan protocal ID
- tag control
-
frame transmission &reception
- 圖
- little endian
-
half/full duplex
-
half duplex
- 同時間只能有一方傳輸
-
full duplex
- 可同時傳送
- 無CSMA/CD問題
- switch需支援
- simulations
- P2P link
- 網卡支援
-
flow control
- 傳送速度>接收速度
-
half duplex解法
-
back pressure
- 假封包 降低傳送速度
- Force collision
-
full duplex解法
- pause frame
-
Gigabyte half duplex challenge
- collision 可能產生
- 最終使用full duplex
-
10 gigabyte ethernet 802.3ae
- full duplex
- 向下相容
- LAN->WAN
-
CSMA/CD
-
goal
- 共享medium
-
carrier sense
- listen before transmitting
-
multiple access
- multiple channel
-
CD
- 停著等
- Topic