Ex. Open database connectivity(ODBC) - Middleware of database
Network layer
Connection - VC network
Connectionless - Datagram network
Analogous to the transport-layer services but,
- host to host
- No choice
Virtual circuit
choose the right path to application, need to call setup first
VC implementation (consist of:)
1.Path from source to destination
2.VC number
3.forwarding table(map of router) in routers along path
Signaling protocol
- use in ATM
- not used in today's internet
Datagram network
- no call setup (connectionless)
- routers
Network layer function
Addressing
- Assignment of address
- Translation (translation process is called address resolution)
Routing
Assignment of address
- Application layer address (URL)
- Data link layer address (MAC address, unique address)
IPv4 Address
- 4 byte, 32 bits address
- Dotted decimal notation (seperate by dot)
Classfull Adressing
Class A : 0 - 127
Class B : 128 -191
Class C : 192 - 223
Class D
Class E
Netid - just specific number
Network address - both Netid and Hostid
ไม่มีความคิดเห็น:
แสดงความคิดเห็น