1 Pertemuan 02 LAN Matakuliah: H0451/Praktikum Jaringan Komputer Tahun: 2006 Versi: 1/0

2 Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : Membangun LAN

3 Outline Materi Hub LAN switch

4 LAN Architecture Topologies Transmission medium Layout Medium access control

5 LAN Topologies

6 Star Topology Each station connected directly to central node –Usually via two point to point links Central node can broadcast –Physical star, logical bus –Only one station can transmit at a time Central node can act as frame switch

7 LAN Equipment Repeaters/Hubs: –At Physical layer –Ethernet can be extended using repeaters –10baseT concentrator is a multi port repeater –amplifies the signal and increase the overall distance – restores the amplitude of the signal –restores signal symmetry –re-timing can be done –can be used for dissimilar media –different LANs cannot be converted – no protocol conversion

8 LAN Equipment Bridges/Switches: –Operates at Data-link layer or MAC layer –Multiple LANs can be connected –Can connect similar LANs with dissimilar media –Can link LANs of different speeds –Passes Packets to the other segment only if addressed to a node in that segment Builds an address data base dynamically (a table with port – address combinations) and use this to filter traffic Hence collision domains are extended only if required –Management software could be used to manage the switches

9 Shared Medium Bus and Hub

10 Two Level Star Topology

11 Hub and Layer 2 Switch

12 Layer 2 Switch Benefits No change to attached devices to convert bus LAN or hub LAN to switched LAN For Ethernet LAN, each device uses Ethernet MAC protocol Device has dedicated capacity equal to original LAN Layer 2 switch scales easily –Additional devices attached to switch by increasing capacity of layer 2