Hi arjun ,
Remote HTTP RAS? Now http is a protocol for serving pages of information over the internet. When ur talking about RAS i guess u mean telnet, ftp, SSH. SSH is the securest of all. FTP is for transferring files and telnet is terminal emulation.
So my guess is u want users who are remotely situated to connect to ur linux box (ex;from a modem ) using telephone lines since ur linux box is not online ...... if iam right then read on.
now u need to configure a s/w called mgetty to achieve this.
read the man pages or search the internet .
Hope this helps.