Operation Manual

Introduction to NetWare MultiProtocol Router for ISDN 3.1 35
♦♦ ISDN interface is released for any other connection
In addition to the Inactivity Timeout, you configure the Disconnect
Timeout for each destination. Both Timeouts are either set to the
same value for one destination or the Disconnect Timeout is set to a
significantly higher value. Whenever a connection is set up by one of
the above described mechanisms, the ISDN interface that has been
assigned by the network administrator to handle the link is activated
and the B channel is set up according to the configuration for the
specific connection. The B channel is cleared down physically by the
Inactivity Timeout and the ISDN interface stays logically connected
and reserves the underlying B channels for the specific connection
until the Disconnect Timeout expires. This may happen either at the
same time or two hours later for example, depending on what you
configured. During the logical up-time (if there is one), an underly-
ing B channel would always be set up automatically to the same
destination and all ISDN line management and other ISDN specific
parameters configured by the network administrator for the specific
connection would be active. As soon as the Disconnect Timeout
expires, the logical ISDN connection is cleared, the ISDN interface is
released and all parameters negotiated during the initial call set-up
and assigned for the specific connection as well as all information
about this connection is "given up". The ISDN interface is then
available for any further connection set-up initiated by any of the
methods described above. Be aware that any following initial con-
nection set-up over the ISDN interface will cause the B channel to be
set up and all ISDN specific features to be negotiated with the
remote site before they are activated, i.e. basically everything config-
ured in the ISDN Network Interface Configuration and everything
configured in the Call Destination Configuration.
This is the basic set up of dial-around links over ISDN. In contrast to
the classic WAN set-up, this set-up cannot be used with bridging,
but it can be applied irrespective of whether you use routing proto-
cols such as IPX RIP/SAP, NLSP or OSPF or configure static routes/
services for IPX, IP or AppleTalk. The two major differences to
classic WANs and interface usage are:
- When setting up dial-around scenarios, it can never be guaran-
teed that the physical link is always available when needed,
because the ISDN interface only reserves the B channels for the
configured destinations until the Disconnect Timeout expires or
another method is used for clear down such as CICC for IPX or
CALLMGR.
Introduc.pm6 27.05.97, 21:0335