WorkerRole在System.dll中抛出'System.Net.Sockets.SocketException'

Question

我使用套接字将id从Web角色发送到辅助角色，然后我等待工作完成，但是当工作者角色中的进程工作时，套接字会抛出带有System.Net.Sockets.SocketException的AggregateException。记录：

 Exception thrown: 'System.Net.Sockets.SocketException' in System.dll
 Exception thrown: 'System.AggregateException' in mscorlib.dll
 Microsoft.WindowsAzure.ServiceRuntime Critical: 1 : Unhandled Exception:
 System.AggregateException: One or more errors occurred. ---> 
 System.Net.Sockets.SocketException: Only one usage of each socket address 
 (protocol/network address/port) is normally permitted

为什么会抛出错误？