In addition to ISO and TCP/IP, what are the other models?

Another significant network model is X.25. This architecture was designed for packet-switched data networks, particularly for wide-area network (WAN) services. X.25 defines interfaces and protocols for connecting data terminal equipment (DTE) to data circuit-terminating equipment (DCE) in a public data network. While predating widespread internet adoption, it provided a robust framework for reliable data transmission over potentially unreliable links, operating with layers that map conceptually to the lower three layers of the OSI model: the physical, link (LAPB), and packet layers. An example of its use and history can be found at Sangoma Technologies.