PyTCP is a Python based attempt to create fully functional TCP/IP stack for educational purposes. Stack operates as user space process attached to Linux TAP interface. As of today stack supports TCP stream transmission over IPv4/IPv6 protocols with sliding window mechanism for basic flow control and retransmissions of lost packets. It can auto-configure it's addresses using DHCP for IPv4 and ICMPv6 Router Advertisements. It is able to send and receive the traffic over Internet using IPv4 and IPv6 default gateways for routing. Since goal of this project is purely educational (at least at this point) the clarity of code is preferred over its efficiency. For the same reason security features are not being implemented just yet unless they are integral part of TCP/IP suite protocols specification.