python telnetlib prompt matching issue

[anna]

import unidecode
import telnetlib
import time
import re
from time import sleep
user = 'user'
password = '1234'
with open('eci.txt','r') as ipfile:
    for sr_no, line in enumerate(ipfile, start=1):
        host = line.strip()
        try:
            print ('Connecting .....')+str(host)
            telnet = telnetlib.Telnet(host, 23, 2)
            telnet.read_until('Login :', 3)
            telnet.write(user.encode('ascii') + '\r')
            telnet.read_until('Password :', 3)
            telnet.write(password.encode('ascii') + '\r')
            #telnet.read_until('>')
            telnet.write('bport all' + '\r\r\r\r')
            telnet.read_until("MCR64A >",3)
            telnet.write(' logout''\r')
            output = telnet.read_all()
            print('\x1b[6;30;42m' + 'Success!' + '\x1b[0m')
            print ('printing output.....')
            sleep(2)
            data = iter(output.split('\n'))
        except Exception as excp:
            print(excp)

getting time out, not able to read_until "MCR64A >" prompt, any suggestion.