X.25 over TCP/IP (XOT) RFC 1613 Cisco-PXS or PXS-PXS

If the customer X.25 implementation predates the X.25 1988 recommendation, the Cisco XOT will most likely require an update for the X.25 software, particularly if non- standard defaults for packet and window sizes are used. If so, instead of using the Cisco router at the branch offices or the central office, the PXS can be used without these limitations.