These standards and recommendations are issued by the International Telecommunications
Union (ITU-T), formerly the International Telegraph and Telephone
Consultative Committee (CCITT), which is a specialist agency
of the United Nations.
There are four series of protocol and standard references
that are commonly encountered in the area of communications
covered by this document. These are
| I Series |
Standards referring to ISDN and related
topics |
| Q Series |
Standards relevant to European ISDN networks |
| V Series
|
Recommendations covering data
transmission over telephone lines |
| X Series |
Recommendations covering the interfacing
of data transmission and terminal devices |
The following list is for reference.
| I Series |
| Number |
Areas Covered |
| I.120 |
Integrated Services Digital Networks |
| I.121 |
ISDN broadband |
| I.150 |
B-ISDN asynchronous transfer functions |
| I.310 |
ISDN functional principles |
| I.311 |
B-ISDN general aspects |
| I.320 |
ISDN protocol reference model |
| I.321 |
B-ISDN protocol reference model and application |
| I.324 |
ISDN architecture |
| I.325 |
ISDN connection reference configurations |
| I.327 |
B-ISDN architecture |
| I.361 |
B-ISDN ATM layer specification |
| I.362 |
B-ISDN adaptation layer functional description |
| I.363 |
B-ISDN adaptation layer 0-5 specification |
| I.364 |
B-ISDN broadband connectionless data service |
| I.365 |
Frame relaying service specific sub layer |
| I.413 |
B-ISDN user interface |
| I.420 |
Basic rate ISDN user interface |
| I.421 |
Primary rate ISDN user interface |
| I.430 |
Layer 1 - Basic rate interface specification |
| I.431 |
Layer 1 - Primary rate interface specification |
| I.432 |
Physical layer - B-ISDN user network interface |
| I.441 |
Data link layer - ISDN user interface |
| I.461 |
Support of data terminal equipment by ISDN |
| I.462 |
Support of packet mode terminal equipment by ISDN |
| I.463 |
Support of V series terminal equipment by ISDN |
| I.501 |
Service interworking |
| I.510 |
Definitions and principles for ISDN interworking |
| I.511 |
ISDN layer 1 internetwork interface |
| I.520 |
ISDN internetworking - general arrangements |
| I.525 |
ISDN to sub 64Kbps internetworking |
| I.530 |
ISDN to PSTN internetworking |
| I.555 |
Frame relay convergence sub layer |
| I.570 |
Public to private ISDN internetworking |
| I.580 |
B-ISDN and ISDN internetworking |