我正在按照这个标准做一个VPN PPTP 服务器，现在我有以下软件包：
客户端->服务器：
Point-to-Point Tunnelling Protocol
Length: 156
Message type: Control Message (1)
Magic Cookie: 0x1a2b3c4d (correct)
Control Message Type: Start-Control-Connection-Request (1)
Reserved: 0000
Protocol version: 1.0
Reserved: 0000
Framing Capabilities: Either Framing supported (3)
Bearer Capabilities: Either access supported (3)
Maximum Channels: 1
Firmware Revision: 0
Host Name: anonymous
Vendor Name:
客户端<-服务器：
Point-to-Point Tunnelling Protocol
Length: 156
Message type: Control Message (1)
Magic Cookie: 0x1a2b3c4d (correct)
Control Message Type: Start-Control-Connection-Reply (2)
Reserved: 0000
Protocol version: 1.0
Result Code: Successful channel establishment (1)
Error Code: None (0)
Framing Capabilities: Either Framing supported (3)
Bearer Capabilities: Either access supported (3)
Maximum Channels: 1
Firmware Revision: 0
Host Name: anonymouse
Vendor Name: anonymouse
客户端->服务器：
Point-to-Point Tunnelling Protocol
Length: 168
Message type: Control Message (1)
Magic Cookie: 0x1a2b3c4d (correct)
Control Message Type: Outgoing-Call-Request (7)
Reserved: 0000
Call ID: 63211
Call Serial Number: 22277
Minimum BPS: 1000
Maximum BPS: 100000000
Bearer Type: Either access supported (3)
Framing Type: Either Framing supported (3)
Packet Receive Window Size: 8192
Packet Processing Delay: 0
Phone Number Length: 0
Reserved: 0000
Phone Number:
Subaddress:
客户端<-服务器：
Point-to-Point Tunnelling Protocol
Length: 32
Message type: Control Message (1)
Magic Cookie: 0x1a2b3c4d (correct)
Control Message Type: Outgoing-Call-Reply (8)
Reserved: 0000
Call ID: 63211
Peer Call ID: 22277
Result Code: Connected (1)
Error Code: None (0)
Cause Code: 0
Connect Speed: 256
Packet Receive Window Size: 8192
Packet Processing Delay: 0
Physical Channel ID: 0
...但不清楚会发生什么，客户端不发送任何内容，一切都挂了？请告诉我客户端和服务器之间的隧道安装缺少什么。