Digital Tansfer Calculation

t1:1.544,  OC-1:51.840Mbps,OC-3:155.251Mbps

1M=1024*1024=1048.576

Estimated time=size of file/bandwidth

2.3 Networking models

Source,destination,and data packets

OSI Reference Model

Layer 7:Application *Layer 6:presentation * Layer 5:Session *Layer 4 Transport *Layer 3: Network *Layer 2: Data Link *Layer 1:Physical

802.3/802.2,HDLN

TCP/IP Reference Model

OSI Model is generic. it can describe TCP/IP Model