Overview of ISDN
The IMG supports (ISDN) Integrated Services Digital Network for a complete
digital telephone/telecommunications network which will carry voice, data,
and video over an existing telephone network. The IMG supports 128 Kbps
high-speed and high-bandwidth service. ISDN non-compressed (512 Kbps compressed)
can also provide on-demand service and can connect up to eight devices
simultaneously with each device being call-managed.
- IMG 1010/1004 - The basic
configuration is 23B+D (Primary Rate Interface) and 30B+D outside
of North America.
- IMG 1010/1004 - Interfaces
to various equipment types supporting the ISDN PRI protocol including
tandem (Class 4) switches and end office (Class 5) switches.
- IMG 1010/1004 - The IMG
ISDN PRI implementation is based on ITU-T Q.921 and Q.931 specifications.
Each implemented variant references the appropriate interface document
supplied by the equipment manufacturer. The interface document is
usually a variant of the ITU-T recommendations.
- IMG 1010/1004 - Supports
up to 32 D channels. Each D channel provides the High Data Link Control
(HDLC) communications over T1, E1, or DS3 on one timeslot on the span.
- IMG 1010 - (NFAS) Each
D channel on the IMG 1010 can control up to 19 other spans in addition
to the span on which it is located.
- IMG 1004 - (NFAS) Each
D channel on the IMG 1004 can control up to 3 other spans in addition
to the span on which it is located.
- IMG 1010/1004 - Supports
sending UUI (User to User Information) between called and calling
parties during the Setup, Clearing, and Active Phase of the Call.
The User to User Information support passes specific information not
pertaining to the call from one user to another.
National ISDN PRI (NI2)
The IMG supports National ISDN PRI (NI2).
IMG 1010:
The IMG supports one D channel per span
[Facility Associated Signaling (FAS)], or one D channel managing up to
20 spans [Non-Facility Associated Signaling (NFAS)].
IMG 1004:
The IMG supports one D channel per span [Facility Associated Signaling
(FAS)], or one D channel managing up to 4 spans [Non-Facility Associated
Signaling (NFAS)].
Connection endpoint variants are defined for National ISDN as User side
and Network side. You can intermix both FAS and NFAS D channels with each
supporting a different variant. See "Configuring
ISDN signaling" for more information