S7C2 – Legacy Ethernet From the Old to the New

Legacy Ethernet Characteristics CSMA/CD Shared Bandwidth 10 Mbps Common Broadcast Physical Star Topology; logical bus

Broadcasts Ethernet characteristic Routers use to announce routing tables ARP request

To Increase Bandwidth Upgrade the user to 10BASE-T full duplex and immediately double the bandwidth. Upgrade the user to 100BASE-X half duplex. Upgrade the user to 100BASE-X full duplex

Frame Transmission Unicast –One source to one destination Multicast –Single data stream from one source to multiple clients Saves bandwidth and controls network traffic Broadcast –Single data stream to all hosts on the subnet

Multicast Cisco has a special multicast address reserved, C-CC-CC-CC, which enables Cisco devices to transmit to all other Cisco devices on the segment. The reserved multicast OSPF IP addresses and translates to MAC multicast addresses of E and E

LAN FRAMES Layer 2 Header – 14 octets –MAC DA 6 octets –MAC SA 6 octets –Type (Ev2) or length (802.3/802.2) 2 octets Layer 2 Data field – 1500 octets –V2 and 802.3data –802.2DSAP, SSAP, Control, Data

Duplex Half-Duplex –Transmit and Receive wires –Relies on Collision Detection Full-Duplex –No loopback –No collision detection –Full duplex ethernet controller Transmit circuit connects directly to receive circuit No collisions Significant performance improvement (almost 100%) Eliminates contention for line Uses single port for each full-duplex connection

Media Comparisons StandardCabTypeModePairsDis-Met 10B-T3,4,5Half B-TX5H &F B-T43H B-T23,4,5H and F B-FXMulti Single H and F1412(H) 2000(F) 10 KM