Question 3.
Can the existing local lines be used for ISDN?
Answer
. Yes, Basic rate access (BRI) use the existing local leads of your existing telephone service. It is possible to convert a normal telephone service to ISDN. In this case the conversion cost is applicable. A network terminator NT will be installed on the premises by ISDN Service Provider and is the termination point for the service.

Question 4
Can we use existing telephone equipment with the voice portion?
Answer.
Yes, existing equipment such as analogue telephones, group 3 facsimile machines and modems can still be used provided that you order the NT+2ab that will provide you with two analogue ports. Alternatively a Network Terminator can be ordered with a privately bought Terminal adapter (or ISDN modem with a terminal adaptor) with analogue ports the analogue devices can be used.

Question 5
How do I connect multiple devices to one BRI line ?
Answer.
Up to eight devices can be connected on a single BRI line. ISDN equipment connects to the S-bus. On the NT+2ab, ISDN equipment connects to the S-bus and the two analogue ports are used to connect analogue devices. The MSN service (Multi Subscriber number) will allow the assignment of multiple numbers to a single BRI. Each ISDN device can be assigned with a different MSN number. Up to a maximum of 3 MSN numbers can be applied for. If analogue equipment is used the two ports on the NT+2ab can be programmed with MSN. If the customer wants to connect a 3rd or 4th analogue device that can be dialled directly on a MSN number then the customer needs to purchase an ISDN modem with a TA. The customer programmes the analogue ports on the TA via the PC controlling the modem.

Question 6
How does a PRI terminate, i.e. what device does Telecom leave at the customers premises, and how many pairs of wires are required. Is the same on a PRI line, but just faster multiplexing or are multiple lines used?
Answer.
The PRI terminates on a G.703 interface and is supplied by Telecom on a Z-screen cable. The frame structure is E1 and the frame rate is 8000seconds x 256bits = 2,048Mbit/s.

Question 7
What type of ISDN switch is used in India, and when using PC software for ISDN, which option is typically selected for switch type ?
Answer
There are two types of switches in the Telecom network namely the Alcatel OCB and the Siemens EWSD. The switch type you must select is Euro ISDN (ETSI) and the protocol type EDSS1.

Question 8
Do we use SPID No's ( Service Provider I D Numbers ) in India?
Answer
No, We use TEI (Terminal equipment identifier).

Question 9
When a NT+2ab customer is busy with a call, and he/she receive another incoming call, the calling party gets a ringing tone, instead of a busy tone. Why is this happening?
Answer.
This happen because of “Call Waiting” features enabled on the ISDN Line as well as on the NT+2ab.

Question 10
Is calling line identification available on ISDN?
Answer.
Yes the CLI supplementary service is available on ISDN.

Question 11
Which ISDN supplementary services are available now?
Answer
Some of the ISDN Supplementary Services available now are as follows:
Call Waiting.
Call Hold.
Three Party Conference.
Call Forwarding Busy, Unconditional and No Reply.
Terminal Portability.
Multiple Subscriber Number (MSN).
MSN for Identification.
Calling Line Identification Presentation (CLIP).
Calling Line Identification Restriction (CLIR). etc. etc.

Question 12
Is Diginet the same as ISDN? What is the difference?
Answer
Diginet is not the same as ISDN, Diginet is a permanent connection whereas ISDN is a switched service. The costs involved for a Diginet connection is a fixed monthly rental, with ISDN there is a fixed monthly rental and an additional usage charge.

Question 13
Is it in fact cheaper?
Answer
Depending on the usage time ISDN could be the cheaper solution. If you spend more than approximately 5 hours a day working on the line the call charges would be more than that of a Diginet connection but if you use it less the ISDN should be more cost effective.