QueueClient Send throw “Could not connect to net.tcp://xxx.servicebus.windows.net:9354/” error

I am using Microsoft.ServiceBus.dll (version 2.1) in order to work on Service Bus for Windows Server 1.1.

We also want this library to be able to talk to Azure Service bus. It only works on the computer in one domain (no port restriction). However on a computer in a more restricted domain (some ports are blocked), I got following error. If I switch Microsoft.ServiceBus.dll 3.0, then the same code works in the restricted domain. Why does Microsoft.ServiceBus.dll 3.0 work and Microsoft.ServiceBus.dll 2.1 does not work in the same lab (domain)?

Could not connect to net.tcp://xxx.servicebus.windows.net:9354/. The connection attempt lasted for a time span of 00:00:20.9992011. TCP error code 10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 40.86.102.100:9354.
at Microsoft.ServiceBus.Common.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.ServiceBus.Messaging.IteratorAsyncResult1.RunSynchronously()
     at Microsoft.ServiceBus.Messaging.MessageSender.OnSend(TrackingContext trackingContext, IEnumerable1 messages, TimeSpan timeout) at Microsoft.ServiceBus.Messaging.MessageSender.Send(TrackingContext trackingContext, IEnumerable`1 messages, TimeSpan timeout) at Microsoft.ServiceBus.Messaging.MessageSender.Send(BrokeredMessage message) at Microsoft.ServiceBus.Messaging.QueueClient.Send(BrokeredMessage message)