Instruction manual

System Features
Integrated Services Digital Network (ISDN) (DK40i, DK424i only)
80 Strata DK General Description 6/00
In Release 4.15, the DK424i enables specifying the minimum and maximum number of B-
channels used for each service on a common set of B-channels in system programming. Minimum
and maximum values can be set for three time periods during the day.
These values can be used to ensure that a minimum number of channels remain available for
incoming calls. They can also be used to determine if calls should be rejected because they exceed
the maximum number subscribed for that service.
Call-by-Call services can be specified to map Strata DK capabilities to network services such as
DID, Tie, FX, WATS, 800, etc. These services can be provided via the local telephone carrier or be
connected to any ISDN inter-exchange carrier.
Outgoing calls, specific numbers, or DID numbers can be checked against the Call-by-Call table
which lists all valid DNs. DNs can be identified on a per station basis to enable billing calls to a
selected service or station. All numbers used for identifying the call must be subscribed from the
providing service, otherwise the call will be rejected by the provider.
Non-Facility Associated Signaling (NFAS)
NFAS provides the ability to create ISDN trunk groups beyond the 23 channels available with a
single PRI. This is extremely important when Call-by-Call Services are used since all B-channels
must be controlled using a common D-channel.
The Strata DK system will support one additional PRI (two circuits to be linked with one
D-channel). This extends the number of call-by-call B-channels to 47 (2 x 24 minus 1). This
provides better performance and cost savings in high volume ISDN PRI applications.
Calling Number Identification Services (CNIS)
CNIS features provide “Calling Party Information” to the network (outgoing calls) and from the
network (incoming calls). There are four types of CNIS services:
♦ Number Provisioning for outgoing calls is controlled by subscription parameters with your
telco provider. The choice is for the number to be necessary or not. The number sent is based
on the call originator and the call type. The originator can be a tandem call, a station (with or
without DID), or a station with a designated number. The type of call refers to whether it is a
direct or redirected (call forwarded) call.
For a tandem call, the Calling Party Number digits received are the digits that will be sent. For
a direct station call, the default number assigned to the selected service, and which is
programmed into the Strata DK as the Listed Directory Number (LDN), will be the number
sent. In this case, the system can send a fixed number (assigned in the system) or it can use the
DID programming to determine the number to be sent.
♦ Number Screening is normally performed by the public network to ensure that the call being
placed has a valid billing number. In systems with a flexible Calling Number Provisioning, the
network can determine if the call is for a valid billing number. Based on this, it can either place
or reject the call, rather than completing the call and billing it to the default LDN.
♦ Number Privacy allows the caller to prevent the public network from delivering the Calling
Number to the called party on a per-call basis. Service subscribers can request that the number
be presented or not, as a default from the public network. Subscribers can also change default
settings. If a public telco service allows changes to be made, then a user can enter change a
code to the setting for that call after selecting a trunk group.