计算机网络-套接字编程作业(2)-UDP ping程序

作业2: UDP ping程序
官方给的服务端端代码：
UDPPingServer.py

import random
from socket import *

serverSocket = socket(AF_INET, SOCK_DGRAM)
serverSocket.bind(('', 12000))

while True:
    rand = random.randint(0, 10)
    message, address = serverSocket.recvfrom(1024)
    message = message.upper()
    if rand < 4:
        continue
    serverSocket.sendto(message, address)

需要自己编写客户端代码，要求
1）发送10个ping的报文到服务器， 格式是：Ping 序号 时间
2） 打印服务器返回的报文
3）计算每个返回报文的RTT时间（往返时间），并打印
4）每个报文的等待服务器回答时间至多1秒，超时则打印报文丢失
因为UDP是非可靠的数据传输协议，我们使用随机数来模拟数据包丢失，设置一个1s的超时响应。
UDPPingClient.py

import time
from socket import *

serverName = '10.21.2.185' # 主机
serverPort = 12000
clientSocket = socket(AF_INET, SOCK_DGRAM)
clientSocket.settimeout(1)  # 设置超时

for i in range(0, 10):
    sendTime = time.time()
    message = ('Ping %d %s' % (i + 1, sendTime)).encode()
    try:
        clientSocket.sendto(message, (serverName, serverPort)) # 发送数据
        modifiedMessage, serverAddress = clientSocket.recvfrom(2048) # 接收服务器的响应
        rtt = time.time() - sendTime # 计算往返时间
        print('Sequence %d: Reply from %s, RTT = %fs' % (i+1, serverName, rtt))
    except Exception as e:
        print('Sequence %d: Request timed out' % (i+1)) # 处理异常
# 关闭链接
clientSocket.close()

运行：

1）打开一个终端运行 python3 UDPPingServer.py 或者 python UDPPingServer.py (python2.x, python3.x其实都可以）
2）打开另外一个终端运行 python3 UDPPingClient.py 或者 python UDPPingClient.py
结果如下：

UDPPingServer.png

UDPPingClient.png

可选练习：

1. 计算所有报文往返时间的最大值、最小值、平均值及丢包率

2. 实现UDP Heartbeat（客户端和服务器端）

练习1:

from socket import *
import time

serverName = '10.21.2.185'
serverPort = 12000
clientSocket = socket(AF_INET, SOCK_DGRAM)
timeout = 1
clientSocket.settimeout(timeout)
rttTimes = []
failPing = 0
for i in range(0, 10):
    sendTime = time.time()
    message = ('Ping %d %s' % (i + 1, sendTime)).encode()
    try:
        clientSocket.sendto(message, (serverName, serverPort))
        modifiedMessage, serverAddress = clientSocket.recvfrom(2048)
        rtt = time.time() - sendTime
        rttTimes.append(rtt)
        print('Sequence %d: Reply from %s, RTT = %fs' % (i+1, serverName, rtt))
    except Exception as e:
        failPing = failPing + 1
        rttTimes.append(timeout)
        print('Sequence %d: Request timed out' % (i+1))
maxTime = max(*rttTimes)
minTime = min(*rttTimes)
sumTime = 0
for x in range(len(rttTimes)):
    sumTime += rttTimes[x]
avgTime = sumTime / len(rttTimes)
loseRate = failPing / 10.0 * 100
print('The minimum RTT: %fs \nThe maximum RTT: %fs \nThe average RTT: %fs' % (minTime, maxTime, avgTime))
print('The packet loss rate: %.2f%%' % (loseRate))
clientSocket.close()

练习2:
超标了，目前不会做 (￣ー￣)