.
, CSMA/CD . , .
, , 64- , . , (jam), . , , . 64- , . tRT TS t, n: tRT=TS*t
TS -. 16- .
, Ethernet.
Ethernet 4- .
802.3/LLC ( 802.3/802.2 Novell 802.2);
Raw 802.3 ( Novell 802.3);
Ethernet DIX ( Ethernet II);
Ethernet SNAP.
802.3/LLC.
802.3/LLC , IEEE 802.3 802.2. 802.3 :
(Preamble) 1010101
(Start-of-frame-delimiter, SFD) 10101011. , .
(Destination Address, DA) 2 6 . 6 . , . 0, (unicast), a 1, (multica). . 0 ( Ethernet), , IEEE.
(Source Address, SA) 2- 6- , . 0.
(Length, L) 2- , .
(Data) 0 1500 . 46 , , 46 .
(Padding) , 46 . . , .
|
|
(Frame Check Sequence, FCS) 4 , .
802.3 -, 802.2 LLC .
Raw 802.3/Novell 802.3.
MAC 802.3, LLC.
Ethernet DIX/Ethernet II.
Raw 802.3. 2- (L) Raw 802.3 Ethernet DIX , 2 .
Ethernet SNAP.
802.3/LLC
SNAP, : OUI . 2- Ethernet II. OUI (Organizationally Unique Identifier) , . SNAP Ethernet II, .
.
() (SFD) -. (DA) 3 : MAC- ; ; . (SA) MAC- , . Data - (LLC) . (FCS) CRC-.
Ethernet Data, . .