What is ISDN?

The acronym ISDN stands for the Integrated Service Digital Network. It is a switched digital network that can be used for the transmission of voice, data, image and video over a single medium. There are two types of accesses available namely the Basic Rate Access (BRI) and the Primary Rate Access (PRI).

What do I get above and beyond plain old telephone service from ISDN?

On a Basic rate access (BRI) you will get 2 x 64Kbps independent logical channels which can be used for voice, data, video and image. In addition supplementary services are available that provides a wider range of features and applications.

Can the existing local lines be used for ISDN?

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.

Can we use existing telephone equipment with the voice portion?

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.

How do I connect multiple devices to one BRI line ?

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.

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?

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.

What type of ISDN switch is used in India, and when using PC software for ISDN, which option is typically selected for switch type ?

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.

Do we use SPID No's ( Service Provider I D Numbers ) in India?

No, We use TEI (Terminal equipment identifier).

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?

This happen because of “Call Waiting” features enabled on the ISDN Line as well as on the NT+2ab.

Is calling line identification available on ISDN?

Yes the CLI supplementary service is available on ISDN.

Which ISDN supplementary services are available now?

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.

Is Diginet the same as ISDN? What is the difference?

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.

Is it in fact cheaper?

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.

Is this guaranteed that the U voltage range from 33V - 120V for NT1 and 42V-120V for NT+2ab?

Yes, it is guaranteed.

What is the minimum power required by NT+2ab from exchange to work in Restricted Mode?

Minimum Power required by NT+2ab+USB to work fine in ab-Auto Restricted Mode is 1700 mW. The unit will work fine with the exchange which is able to provide at least 1700 mW.

In which Mode the programming of features is possible in NT+2ab?

All programming of features can be done in any mode i.e. Normal or Restricted. During programming in Restricted Mode ab port should be configured.

How long does the setting inside the NT+2ab that are programmed from the analog phone will last?

The setting will last forever unless changed by the user.

What happen if user skipped the subscription of MSN number to each analog port, but proceed to set the MSN for identification?

If user skipped the subscription of MSN number, but proceed to set the MSN for identification. Then by default always Main line number will be set as MSN for Identification.

In MSN for Identification, what is the first setting mean (Y890#)?

For this feature user configurable "CLIR enable / disable facility" through functional code, should be present on the ISDN Line. It will restrict the number i.e. when user select this, no number will be present to the called party during an outgoing call from that port.

Why the call forwarding functionality is not working on the MSN numbers, while it is working on the main number?

The Call Forwarding facility on the MSN's number will also work when the Exchange provides it on all MSN’s number also.

How Internal Call can be make, and will it be charged?

When both of the analog ports are connected with analog phone, users will be able to perform internal call (like intercom) from one to another by pressing *00*. This call will not be charged.

How far can an analog phone be from the ab port (the cable length)?

It depends upon the impedance of analog phone as well as the cable connected between analog phone and ab – port. The total impedance should not be greater than 600 Ohm.

Is all the features of NT+2ab+USB is provided by Exchange?

Some of the features of the NT+2ab+USB requires services offered by the exchange, thus, users have to subscribe the services first to enable it. For example, call waiting, call hold, call forwarding etc.

How do I program numbers into the digital ports on the NT+2ab?

The programming is done on the customer's equipment. The MSN number is programmed into an ISDN telephone or on the PC controlling the ISDN modem.

What is USB?

USB is a peripheral bus specification developed by PC and telecom industry leaders -- Compaq, DEC, IBM, Intel, Microsoft, NEC and Northern Telecom -- that brings plug and play of computer peripherals outside the box, eliminating the need to install cards into dedicated computer slots and reconfigure the system.
Personal Computers equipped with USB allow that you don't even need to shut down and restart your PC to attach or remove a peripheral. USB also allows multiple devices -- up to 127 -- to run simultaneously on a computer, with peripherals such as monitors and keyboards acting as additional plug - in sites, or hubs.

Why does MS-Windows XP keep on popping up the warning message windows during driver installation?

The annoying warning message windows keep on popping up because Ascom do not pay to obtain ISDN USB TA digital signer from the Microsoft Windows XP Publisher. However, this inconvenience won't effect the ISDN USB TA’s function in any aspects. You may ignore the warning messages by clicking the 'Continue Anyway" button during driver installation.

My ISDN USB TA cannot be used to connect to the Internet after waking up from the power-saving mode. What can I do?

This issue is caused by some hardware incompatibility among USB devices. Please use either of the following methods to resolve this issue:
1. If you are using USB hub, plug ISDN USB TA into your PC's USB port directly.
2. Plug ISDN USB TA to another USB port of your PC.
3. Plug out and re-plug in the ISDN USB TA to your PC.

I check both NDISWAN and ASCOM ISDN MLPPP as my virtual modems, but it turns out the connection to the Internet is extremely slow and instable. What can I do?

Please select only virtual modem to resolve this issue.

How do I connect to the Internet with 128K?

For ASCOM ISDN MLPPP, two B channels are used at first. Then you may use Byte Bar to add/drop the second B channel.
For ASCOM ISDN Dynamic MLPPP: connection speed is 64Kbps first, then the second channel will be automatically added/dropped by BOD mechanism.
For ASCOM ISDN PPP, one B channel is used at first. Then you may use Byte Bar to add/drop the second B channel.
For NDISWAN, please follow the procedures below:

For Win98/Me:

a. Set up a new connection in the Dial-Up networking folder.
b. Right-click the connection icon and select "Properties".
c. In the field "Multilink", click on the setting button.
d. Activate the option "Use additional devices" and then click on the Add button.
e. In "Device Name" select the unused NDISWAN device, i.e. "WAN-Line0X".
In the field "Phone Number", type the same number used for your connection.

For Win2000/XP

a. Select "My Network Places" option on the desktop and right-click it.
b. Right-click "Dial-up Connection" and select "Properties".
c. In "General", you can click both "NDISWAN driver". Then it will connect at 128K.

My modem type is chosen as ASCOM ISDN MLPPP. Why can't I connect to the Internet?

It may cause by the MLPPP protocol is not supported by your ISP. Please select ASCOM NDISWAN protocol as your modem type.

USB port Call Bump-In features enable users to connect to the Internet at 128 kbps, by utilizing both channels, but Telecom will charge users on per channel basis. Is there any way that the users can set to connect by only using 1 channel?

Yes, users are able to set default connection type to one channel or using both channels by selecting a proper protocol before connection is made. Select ‘Ascom ISDN PPP’ for 64kbps (one channel) or ‘Ascom ISDN MLPPP’ for 128kbps (2 channels).

When utilizing both channels, can the users make or receive call?

Yes, the users are able to make or receive call when utilizing both channel with the help of Call Bumping feature. One channel will automatically drop to allow the call and automatically up again once the call is ended (case if the user select Ascom MLPPP protocol).

When in restricted mode, does USB modem still functioning, which allow user to surf the Internet?

Yes, USB modem will always work independently, whatever port may be configured in Restricted Mode.

Why my PC is now not detecting the USB modem, although it was working fine earlier on the same PC?

The USB driver is not uninstalled properly. Before installing USB driver, please ensure that all previously installed USB driver is Uninstalled properly from the PC. After uninstalling, please restart the PC and then follow the procedure for installing USB driver as mentioned in the Manual.

I am doing testing on call bump-in which we can surf the Internet at either 64/128 kbps. I am connecting using MLPPP which allow me to connect at 128kbps. from the byte bar, I noticed 2 channel being occupied. When I click on the task bar to drop the 2nd channel, the byte bar shows only one channel being occupied, but, the speed indicate that I still surfing at 128 kbps. What happen here, am I surfing at 128 kbps using only one channel?

Here Speed indicates the maximum speed, which user can get with this connection and not the actual speed of Data Surfing. Actual speed of Data Surfing user can check on Byte Bar Rx CPS and Tx CPS. And if user will connect to the Internet with 64 kbps connection provided by the ISP, then only user will get the speed indicated as 64 kbps.

What is BONDING?(Multilink service)

Bonding is when the two B channels are combined to form a logical channel of 128Kbps. It is also referred to as inverse multiplexing. This is done on the customer's ISDN modem or router.

The customer must confirm with their ISP (Internet Service Provider) that they are a 128 kbps user. This service normally comes at a higher cost.

To achieve 128 kbps the customer's modem must be set-up for 128 kbps and the modem will make 2 calls to the ISP, each call occupying a 64 kbp/s channel. As both channels are being used, no further calls are possible on the line. (However should the modem supports "bandwidth on demand", the modem will drop 1 channel to receive the call.)
Please note that the customer will be billed for two calls, due to the fact that both channels are in use.

Why do I get billed for short calls?

Precaution should be taken with the 128 kbps bonding service. Should the customer only require a 64kbps service, and the modem is incorrectly set up for 128 kbps, short calls will occur. Short calls are established when a 64 kbps customer's modem is incorrectly set-up for the 128 kbps service. The modem will dial out on 1 x 64 kbps channel and connect to the ISP and authenticate. The modem then makes a second attempt/call on the remaining 64 kbps channel and connects to the ISP. The ISP fails the authentication as the customer is already connected on that user name and password. (The ISP does not accept the 64 kbps subscriber as being a 128 kbps (Multilink) subscriber.) The second call is dropped. The second call takes about 2 seconds to connect and fail authentication. While the customer is surfing on the 1x 64 kbps channel the modem will keep on trying to establish the 2-second connection/call.

How can I prevent short calls and how can I correct my modem settings?

Customers should select PPP protocol instead of MLPPP for 64 kbps connection and / or need to phone their ISP for assistance on correct modem settings. Correct modem settings will eliminate short calls from appearing.

What extra hardware will I need with NT+2ab for Internet Surfing (handsets/Modems/ Routers/etc..)?

When using NT+2ab for Internet access you will be supplied with a line and a network terminator. In addition to that you will need an ISDN internal or external Terminal adaptor for Internet Surfing. Better you go for NT+2ab+USB.

What are the effects of values in Byte Bar’s PPP setting?

When Dynamic MLPPP is chosen as your modem, the 2nd B channel will be automatically added /dropped according to the values in the PPP tab.

What should I type in the Byte Bar’s MSN setting?

The Multiple Subscriber Number (or MSN) is an ISDN feature that allows you to have more than one directory numbers for a single BRI. If you have more than one ISDN devices connected to NT1, assign a specific MSN to ISDN USB TA and it will accept only the incoming call directed to the specified MSN, for example, if you assign an MSN "5013400" to ISDN USB TA, it will only accept calls with "Called Party Number" as 5013400. You can set up to 10 MSNs for ISDN USB TA, There aren't any assigned MSN's by default, i.e. ISDN USB TA will accept all incoming calls from every port.

What should I choose for Analog Coding Method in Byte Bar's Switch tab?

In information Byte Bar's Switch tab, please choose A-law for European ISDN users and U-law for Taiwanese and American ISDN users. For other areas, please make sure which analog coding method your local teleCom is using, otherwise there will be problems for FAX, V.23, and V.22 bis connections.

What is the main information provided by Byte Bar?

The Byte Bar provides comprehensive on-line information for each call. In the standard display mode, it displays:

- Direction of the call (Originate or Answer Mode).
- Call progress status, such as Dialing, Proceeding, and connect protocol. etc.
- Connection time of the current call.
- Transmitting / receiving data rate (in CPS or Character Per Second).
- Charging information, if any.