question: public static void ensureRouteToHost ( Context context , String url , String proxy ) throws IOException { ConnectivityManager connMgr = ( ConnectivityManager ) context . getSystemService ( Context . CONNECTIVITY_SERVICE ) ; connMgr . startUsingNetworkFeature ( ConnectivityManager . TYPE_MOBILE_HIPRI , "enableMMS" ) ; if ( LOCAL_LOGV ) Log . v ( TAG , "ensuring route to host" ) ; int inetAddr ; if ( proxy != null && ! proxy . equals ( "" ) ) { String proxyAddr = proxy ; inetAddr = lookupHost ( proxyAddr ) ; if ( inetAddr == - 1 ) { throw new IOException ( "Cannot establish route for " + url + ": Unknown host" ) ; } else { if ( ! connMgr . requestRouteToHost ( ConnectivityManager . TYPE_MOBILE_MMS , inetAddr ) ) { throw new IOException ( "Cannot establish route to proxy " + inetAddr ) ; } } } else { Uri uri = Uri . parse ( url ) ; inetAddr = lookupHost ( uri . getHost ( ) ) ; if ( inetAddr == - 1 ) { throw new IOException ( "Cannot establish route for " + url + ": Unknown host" ) ; } else { if ( ! connMgr . requestRouteToHost ( ConnectivityManager . TYPE_MOBILE_MMS , inetAddr ) ) { throw new IOException ( "Cannot establish route to " + inetAddr + " for " + url ) ; } } } }
target:  Ensures that the host MMSC is reachable