X.25
E93647
X.25 is an early ITU-T packet-switched network protocol standard widely used for WAN communication before the rise of modern IP-based networks.
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
ITU-T recommendation
→
packet-switched network protocol → wide area network protocol → |
| category |
network layer protocol
→
telecommunications standard → |
| definesInterfaceBetween |
data circuit-terminating equipment
→
data terminal equipment → |
| hasAddressingScheme |
X.121
→
|
| hasLayer |
link layer
→
packet layer → physical layer → |
| influenced |
ATM
→
Frame Relay NERFINISHED → early IP over X.25 deployments → |
| introducedIn |
1970s
→
|
| operatesOver |
ISDN
NERFINISHED
→
circuit-switched networks → leased lines → |
| provides |
connection-oriented service
→
reliable packet delivery → |
| replacedBy |
Frame Relay
→
MPLS → TCP/IP → |
| standardizedBy |
CCITT
→
ITU-T NERFINISHED → |
| status |
largely obsolete
→
|
| stillUsedIn |
some legacy systems
→
|
| supports |
error correction
→
flow control → link-level retransmission → permanent virtual circuits → switched virtual circuits → virtual circuits → |
| usedBefore |
widespread adoption of IP
→
|
| usedFor |
host-to-host communication
→
packet-switched WAN communication → public data network access → terminal-to-host communication → |
| usedIn |
airline reservation systems
→
financial transaction networks → legacy point-of-sale networks → public data networks → |
| usesLinkLayer |
LAPB
→
|
| usesPacketLayer |
PLP
→
|
| usesPhysicalLayer |
EIA-232
→
EIA-449 → X.21 → |
| widelyDeployedIn |
1980s
→
1990s → |
Referenced by (1)
| Subject (surface form when different) | Predicate |
|---|---|
|
ITU Telecommunication Standardization Sector
→
|
notableStandard |