WCF - SessionChannel- How does it really work
**A.** I have failed to understand over and over from this ( http://msdn.microsoft.com/en-us/library/aa751829.aspx ) article why should we use it and how does it work: 

1. **Datagram with sessions**
2. **Request-response with sessions**
3. **Duplex with sessions**


**B.** Let's assume that I have a Service with InstanceContextMode = InstanceContextMode.PerSession, ConcurrencyMode=ConcurrencyMode.Single. If I have 2 clients for this service and they activate a method in that setrvice at the same time, why should one of them wait until the service finish the other one request?; PerSession + 2 clients = "2" services that each of them have  ConcurrencyMode.Single. Where is my mistake?
WCF - SessionChannel- How does it really work
===

**A.** I have failed to understand over and over from this ( http://msdn.microsoft.com/en-us/library/aa751829.aspx ) article why should we use it and how does it work: 

1. **Datagram with sessions**
2. **Request-response with sessions**
3. **Duplex with sessions**


**B.** Let's assume that I have a Service with InstanceContextMode = InstanceContextMode.PerSession, ConcurrencyMode=ConcurrencyMode.Single. If I have 2 clients for this service and they activate a method in that setrvice at the same time, why should one of them wait until the service finish the other one request?; PerSession + 2 clients = "2" services that each of them have  ConcurrencyMode.Single. Where is my mistake?