Dear Mr. AnandThis is chitan Upadhyay from India, I have referred your config, please confirm which make of external modem you are using. Also do u have analog modem port card installed in your router.RegardsChintan UpadhyayGujarat StateIndiae-mail: ...

By default cisco routers are configured for sync mode only, in order to hook up the external modem you can use this commandphysical layer-async ( Means you are configuring this port for async connection)RegardsChintan UpadhyayC...