XOT

XOT (X.25 Over TCP) is a protocol developed by Cisco Systems that enables X.25 packets to be encapsulated and routed through TCP/IP connections instead of LAPB links. In 2012, X.25 tunnelled over TCP/IP using XOT was noted as by then being likely more common in actual use than physical X.25 over LAPB.

References

Network protocols
X.25

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