09-09-2016, 04:10 PM
1454225706-nethardware.ppt (Size: 2.19 MB / Downloads: 11)
Subnet Layer
Transmission of Messages
1. Within a Single Subnet, or
2. in Point-to-Point Links Between Subnets
Internetting
internet: collection of subnets such that any station on any subnet can communicate with any other station on any other subnet simply by giving the internet address of the other station.
LANs, MANs, & WANs
LAN
Local area network
Single office, building, campus
10 Mbps to 100 Mbps to the desktop common
1 Gbps coming
Will carry most traffic, because most traffic is local
WAN
Wide area network
Intercity, international
9,600 bps to 1 Mbps common to the desktop
Links with higher speed are usually shared (multiplexed) by several desktops
Emerged before LANs, due to high cost of long-distance telephone charges
Some basic concepts
NDIS Interface: Network Driver Specification Interface, wraps NIC drivers and allow communication with multiple protocols, binds a NIC to a protocol.
Streams: multiple channels allowing broader bandwidth for data transfer, envelop the protocols.
Transport Driver Interface: allows software drivers (server, redirector, etc) to communicate with protocols.
Redirectors: software in WS that redirect network drives, printers requests to network I/O requests.
Servers: software that allows a device to accept requests from other devices.
Standard protocols
NetBEUI - NetBIOS Extended User Interface, “native” Windows protocol, not routable.
TCP/IP - implemented through WinSock, routable, supports SNMP, DHCP, WINS.
NWLink (IPX/SPX) - used to connect to Novell NetWare, just a protocol, not access.
DLC - Data Link Control, used to connect to IBM mainframes and HP printers directly connected to a network (server).