X.75 is an ITU-T protocol that defines how to interconnect multiple private X.25 packet switching data networks, allowing them to share resources and data across international and multiprovider areas by connecting backbone packet switches and translating addresses between networks. It supports multilink procedures between signaling terminal exchanges to facilitate communication between devices in separate X.25 networks located in different countries, like the US and UK, with the X.75 link being transparent to the end users.

1. X.75 Internetworking
Protocol
By: Ms. Pradnya Saval
Asst. Prof. TCET
Mumbai

2. X.75 Internetworking Protocol

3. X.75 Internetworking Protocol (Cont..)
• ITU-T Recommendation X.75 defines the protocol structure and procedures
for internetworking multiple X.25 packet switching private data networks
(PSPDNs).
• X.75 can be used to:
• share network resources and data across the international or mutiprovider area.
• connect larger backbone packet switches to one another.
• Translate address in conjunction with the X.121 address protocol standard.
• Multilink procedures to support multiple links between signalling terminal exchange (STE).

4. X.75 Internetworking Protocol (Cont..)
• The figure shows DTEs from 2 separate X.25 networks located in US and
UK communicating via X.75 protocol.
• The X.75 link is transparent to the end user.
• The figure is an example of X.75 being used as an international packet
switching service.