Specifications

Cost Assignment (COSO, Charge One Site Only)
80 AVM Access Server – 5 AVM Access Server Concepts and Functional Principles
5.6 Cost Assignment (COSO, Charge One Site
Only)
The ISDN feature “D channel signaling” is provided free of charge by
most ISDN operators, and is used by the AVM Access Server to imple-
ment cost allocation (COSO, Charge One Site Only).
COSO allows you to specify which end of the network link bears the
connection charges. For each remote network user group, this may be
the local ISDN Access Server, or the remote site, or whichever site ini-
tiates the connection.
Because COSO uses unique ISDN features and is not yet incorporated
in PPP standards, the remote user must have access software that also
supports this function, such as NetWAYS/ISDN.
The following diagram illustrates how an incoming call is handled with
cost allocation set to “Local site” (in other words, the AVM Access
Server bears the connection charges).
Incoming call handling when Cost Allocation is set to “Local site”
Acceptance of the
incoming call
(after authentication,
if required)
ISDN
D channel
Signal of connection
request
D and B channel
Transmission of
data packets in
both directions
Idle ISDN
connection
cleared
D and B channel
Transmission of
data packets in
both directions
Local Site
(AVM Access Server)
Connection request
rejected.
Call-back with
costs carried by the
local end
Data packet for
the remote
site, e.g. e-mail
Remote site identified
by means of the
D-channel number
D and B channel
Remote Site
(AVM Access Server)
Data packets for
the remote
network
Acceptance of the
incoming call
(after authentication,
if required)
D and B channel