Peer-to-peer
Client/server
Domain name server
Application
Physical
Data link
Network
Both a and b
Message envelope
Message header
Message body
Message notification
WWW
HTTP
TCP
UDP
Intranet
Telnet
FTP
Search engine
IRC
DCCP
SCTP
SNMP
POP3
IMAP
IMAP4
MIME
Two
Three
Four
Five
CSS
PHP
Javascript
HTML
STMP
VOIP
PSTN
Podcast
Data sync
Collaborative computing
Groupware
e-governance
e-commerce
e-banking
None of the above
CGL
SGML
Meta search engine
Hyper search engine
IP
Web
Host