Client starts with 100.
Server starts with 500.
When they will establish connection...each will use one sequence no. So seq no 100 is used by client and 500 is used by server.
Now client sends two 100 bytes packets. So its seq no upto 300 will be used for this.
Server sends 50 bytes of data. So seq no upto 500 is used.
Now when client will send acknowledgement, it will use 301 as sequence no and will give 501(next byte expected) as acknowledgement no to server.
