Go to Settings > Wireless & networks > More… > Mobile networks > Access point names
Press the Menu > New APN
Enter name: Etisalat
APN: wap
Proxy: not set
Port: not set
Username: not set
Password: not set
Server: not set
MMSC: not set
MMS Proxy: not set
MMS Port: not set
MCC: 413
MNC: 03
Authentication type: None
APN type: default,supl (if Samsung Galaxy, select Internet)
APN protocol: IPv4
Please note that these settings are valid for Etisalat Sri Lanka only.