Operation Manual

60 NetWAYS/ISDN – Glossary
authentication, the name and password assigned by the re-
mote administrator must be entered as well. Obtain this in-
formation from the administrator of the remote site.
Bchannel
An ISDN basic access consists of two B channels and one
D channel. The B channels are used to transport user data.
They allow transmission at a rate of 64 kbit/s. B channels
can be bundled to accelerate transmission.
CAPI
See “COMMON-ISDN-API (CAPI)” on page 61
CHAP (Challenge Handshake Authentication Protocol)
One of the two authentication protocols in the PPP suite. To
perform an authentication, the local and remote sites must
have the assigned name and password entered in their con-
figuration for the connection. The remote system must be
configured to present the same name and password. Under
CHAP, the site requesting the authentication generates a
message from the user name and a random value according
to a defined encryption algorithm, and sends the message to
the remote site. The remote system produces a new message
out of the first message and the password, also using a pre-
set algorithm, and sends this value back. The first site per-
forms the same operation and compares its results with the
message received from the remote system. If they match, the
remote system is authentic and the connection can be set
up. The advantage of this method is that the password itself
is never transmitted between the two systems. For this rea-
son CHAP is considered a secure protocol. CHAP is described
in RFC 1334 and RFC 994.
CLI (Calling Line Identification)
ISDN terminal devices can transmit their line number over
the D channel with outgoing calls. CLI is an ISDN feature
used by NetWAYS/ISDN to identify incoming calls.
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