Concepts and Principles of Operation
7
Directory numbers
A directory number is the address or telephone number for the ISDN line assigned by your ISDN service
provider or telephone company. The number of directory numbers allocated depends on which Service
Provider you are using. If you are using an NI-1 line, you will be assigned one directory number per B-
channel. Otherwise, you will be assigned one directory number per device.
Service Profile Identifiers (SPIDs)
Note: Service Profile Identifiers are only allocated by Service Providers in North America.
When you order an ISDN service, your Service Provider needs to know which ISDN features you
require, for example, Calling Line Identification (Caller ID). This is known as a service profile. Your
service provider then allocates you a unique Service Profile Identifier (SPID) that allows you to use
these particular features.
Depending on your ISDN variant, you will have none, one or two SPIDs assigned to your ISDN line as
shown below.
ISDN Variant
Directory numbers
SPIDs
AT&T 5ESS P-P
1 (1 per device)
None
AT&T 5ESS M-P
2 (1 per B-channel)
2 (1 per B-channel)
NTI DMS
2 (1 per B-channel)
2 (1 per B-channel)
NI-1
2 (1 per B-channel)
2 (1 per B-channel)
NI-2
1 (1 per device)
1 (1 per device)
European
1 (1 per device)
None
1TR6
1 (1 per device)
None
NTT
1 (1 per device)
None
Austel (TS013)
1 (1 per device)
None
AT&T Point to Point ignores the Directory number from the user equipment, so you could be sending
anything that will sync up, and it will place a call. One should leave the SPIDs blank while configure
the Hypertec ISDN 10T Router for AT&T Point to Point Switch. ATT Multi-point, NTI, and NI1 are
very specific about DN directory Number and SPID numbers. If they are wrong, you cannot place a
call.
56K/64K Rate Adaption
The Rate Adaptation of the line is the speed at which data can be transmitted over that line. This can be
64 KBPS or 56kbit/s. If you are connected to a European ISDN Service, always set the Rate
Adaptation to 64 KBPS (the default value). If you are connected to a North American ISDN Service,
always select 64 KBPS for local calls. You may need to select 56 KBPS for international or some
inter-state calls. Some area in North America, dialing 1+10 digit is required in order to access the
64kbit/s. You should generally select 64 KBP in most part of the world.
ISDN Permanent (Nailed) Circuit
Most telephone companies offer only switched ISDN circuits. In. Germany leased line ISDN service is
also offered as a option. German ISDN Permanent connection services (types 64S, S01 and S02) is
available from Deutsche Telekom. This service provides a permanently open leased line with an ISDN
interface at each end, which allows you to take advantage of Deutsche Telekom tariff rates.
Service type
Number of channels
64S
One B-channel
S01
One B- and one D-channel
S02
Two B- and one D-channel
Japan NTT also offers leased line ISDN service :
