connection - Why SIM800F disconnect when TCP connect is established?

Question

We are using SIM800F with pyboard, and trying to connect to SSH server with TCP connection. The problem is that as soon as we successfully connect to the server and get OK response the GSM module disconnects and we have to reset it. Also, when we close the TCP connection the GSM module reconnects again! This is our code:

#main.py -- put your code here!

import pyb
import time

uart = pyb.UART(4, 9600)
uart.write('AT+CGATT=1
') #attached GPRS
uart.write("AT+CSTT="taif"
")
#uart.write('AT+CIPMUX=0
') #enable single IP connection
print(uart.read())

print("reading data from server ...")

uart.write("AT+cipstart="TCP","64.225.22.181","22"
")

Answer 1

等待大神答复