In emerging smart grid networks, massive amounts of data will be continuously generated from measurement devices embedded in the power grid such as phasor management units (PMUs), intelligent electronic devices, advanced meters, or electric vehicle charging stations. Data generated from these measurement devices must be delivered immediately, reliably, and safely to specific locations for wide-area monitoring and grid control. The transport requirements for periodic measurement data are characterized as continual, reliable, and secure delivery of small-sized packets (less than 1.5 KB) over a utility-owned wide area network (WAN). Motivated by our assessment that no well-known transport protocol adequately meets these requirements, we designed the Smart Grid Transport Protocol (SGTP) for smart grid networking. Compared to Transmission Control Protocol (TCP), we show through simulation studies that SGTP can indeed achieve lower latency while preserving reliability and lightweight communication overhead and supporting inherent security extensions. © 2011 Alcatel-Lucent.