This chapter focuses on the description of transport network architecture suitable for 5G in terms of both user plane (UP) and control plane (CP). The 5G UP architecture considers converged optical and wireless network domains in a common 5G infrastructure supporting both transport and access. Given the great degree of technology heterogeneity in the transport network, special emphasis was given to technology integration and interfacing aspects. The chapter provides an overview of the various technologies and protocols and the associated interfaces that can be used in support of both fronthaul (FH) and backhaul (BH) services, and addresses self-backhauling. The concept of self-backhauling offers a flexible and cost-effective approach to address both BH and access requirements by dynamically sharing the radio resources between BH and access links. The chapter discusses framing protocol adaption and interfacing aspects. It presents a discussion on transport network optimization and performance evaluation.