Protocol stack of Wireless Sensor Network (WSN) contains five layers. These are also called standard protocol layers. In this transport layer protocols plays an important role in handling the congestion and maintaining the reliability. This layer mainly provides these both functionalities: congestion control and reliability. Transport layer helps in connect to other system and provide connectivity goals. There are so many protocols already exist to handle the congestion and provide the reliability. In this paper we are representing a review on transport layer protocols of reliability and congestion control. We also give a brief introduction of WSN networks. Later we separately described the protocols and disadvantage of UDP and TCP traditional protocols of transport layer protocol.