web accelerator and wan optimization

Hi all,

we have site A and site B, Both sites connected with wan links. Most of our applications are hosted in site A & only one application is hosted in site B. Users in site A also using application hosted in site B, During the accessing site A users facing application slowness issue.

Both site have F5 4000S with 11.5

From some web search we come to know through AAM we can improve the application performance. But in AAM there are two option is there web accelerator and wan optimization.

Please suggest us which is the best module for improve the performance of remote hosted application.

Also please share URL link about AAM.