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What is ISDN - Integrated Services Digital Network?
Generally, the user is connected to the network by analog lines. Signals are then digitized And all communications within the network are digital. ISDN brings the digital Network Individual User
Thus, the same twisted copper telephone line, which traditionally could only carry one Voice, or a Computer or a fax "communication" can now be taken as three separate "Connection" at the same time through the same line. ISDN is "magic" that makes it happens.
The basic ISDN-to-user connection, called BRI, is for the basic rate interface, Includes three different channels. Two of these channels are called B channels, users move Communication with a telephone, a Computer, fax or almost any other device. The third The channel which is called the D channel provides call setup information for the network, but it can also User data transmission, even if it is not normally used for this purpose
This means that two different "communications", say, a voice call and a computer Transmission can happen through the same ISDN line at the same time. Power of ISDN enables both of these broadcasts at the same time, through the same copper Twisted pair telephone line that can handle only one transmission once.
ISDN allows more information, more reliably and at high speeds, and in most The case without changing telephone wiring in your house or building. One more advantage Fast connection establishment For example, with ISDN, it only takes a few seconds Relate to the Internet with 40 seconds for the analog connection.
There is another type of ISDN called PRI, which is the primary rate for the interface Generally used by companies. The PRI includes 32 different channels. One of these The channels are D channels and the rest are B channels.
ISDN has been standardized by ITU. ISDN has different configurations. used in Europe is called Euro-ISDN.
Different costs are included with ISDN. First, you have a fixed fee for ISDN Contribution Then you have an installation cost each time you make a new connection Through ISDN network. In the end, you will have to pay for what you are connected to.
ISDN is used for many different applications. An example is a bandwidth on demand, which This means that when the lease connection is overloaded, then ISDN is used as an additional backup.
What components does ISDN need to work?
First, you need to have an ISDN subscription from a service provider. Then you need a line box
NT, which is called the Network Terminal Device. Is established in Europe by Service provider, but in the USA it must be bought and installed by the user. you should also Terminal adapter. This adapter is sometimes called ISDN modem or ISDN router.
Finally, you need terminal equipment such as a PC or ISDN telephone.
Basic rate interface
Basic Rate Interface or BRI is defined as two 64 kbps bearer channels and one 16 kbps data channel. D channel generally takes call setup data, but the user can also move Data across the network The BRI interface is also referred to as a 2B + D connection. Primary rate interface
The primary rate interface or PRI is defined as many 64 kbps B channel and one 64 kbps d channel. The primary rate interface has different configurations Countries PRI contains 23B + D configuration in the United States. In this quantity Total bandwidth of 1.5 Mbps, and is designed for broadcast via a standard answer American T-1 trunk.
ISDN has been standardized by ITU. ISDN has different configurations. used in Europe is called Euro-ISDN.
Different costs are included with ISDN. First, you have a fixed fee for ISDN Contribution Then you have an installation cost each time you make a new connection Through ISDN network. In the end, you will have to pay for what you are connected to.
ISDN is used for many different applications. An example is a bandwidth on demand, which This means that when the lease connection is overloaded, then ISDN is used as an additional backup.
What components does ISDN need to work?
First, you need to have an ISDN subscription from a service provider. Then you need a line box
NT, which is called the Network Terminal Device. Is established in Europe by Service provider, but in the USA it must be bought and installed by the user. you should also Terminal adapter. This adapter is sometimes called ISDN modem or ISDN router.
Finally, you need terminal equipment such as a PC or ISDN telephone.
Basic rate interface
Basic Rate Interface or BRI is defined as two 64 kbps bearer channels and one 16 kbps data channel. D channel generally takes call setup data, but the user can also move Data across the network The BRI interface is also referred to as a 2B + D connection. Primary rate interface
The primary rate interface or PRI is defined as many 64 kbps B channel and one 64 kbps d channel. The primary rate interface has different configurations Countries PRI contains 23B + D configuration in the United States. In this quantity Total bandwidth of 1.5 Mbps, and is designed for broadcast via a standard answer American T-1 trunk.
In Europe and the Pacific, the transmission standard is different from those used in the United States. The primary rate interface is supplied through a standard 2 Mbps E-1 channel and is included in it In Europe either 30B + D configuration is used or Pacific 31B + D configuration is used.
Although the specifics of the ISDN implementation are still slightly different from the nation The relationship between any two systems in the nation, the world, is no longer possible, But fast practical
Different types of cable buses are used in ISDN.
Minimum bus configuration is the maximum length between NT and terminal devices 140 meters Terminal equipment can be connected anywhere in the bus.
Maximum length between NT and the terminal device in extended bus configuration 500 meters. Although there are some restrictions on where terminal equipment is Is connected to the bus.
In both small bus configurations and extended bus configurations, you can connect up to 8 Terminal device, but the maximum length between the two terminal devices is 50 Is the meter.
The point-to-point bus can be connected to a terminal device only in the configuration NT The maximum length between NT and terminal equipment is 750 meters.
An application is a WAN backup, where you use ISDN with a leased line. when The leased line overloads or activates the ISDN connection.
Another application has remote access. It can refer to Internet access or access to a LAN Away from the place
A third application is Symbian Voice, Fax and Data. It can be very convenient People working from home
ISDN can also be used as a WAN service, which connects two LANs to each other.
A popular application for ISDN is LAN connectivity. Max bandwidth between If BRI is used then LAN is 128 kbps. If PRI is used then the maximum bandwidth is 2 Mbps.
The ISDN call is automatically made by the router only when the data is sent Network on the other hand. Time of connection establishment is very short and there are There is practically no delay when traffic flows. A timer configured by the owner of the router After some time the ISDN connection can be set to disconnect.
One of the main uses of ISDN is the high speed of the Internet. At most For the Internet, such as audio and video applications, demand high bandwidth Satisfactory result Normal 28.8 Kbps is no longer sufficient. For alternative Individuals and small companies, use ISDN.
In the picture,e you can see the general configuration used by a small company. equipment ISDN is connected to ISDN via Router, which has BRI connections. in this matter The maximum bandwidth for internet communication which can be 128 kbps for a single user.
In the picture, we can see two types of configurations. The first type is an ISDN The card installed in the PC, which can communicate directly with NT. It's the cheapest Solution, but up to two users can have ISDN access.
In another type, an ISDN router is used. Many users in this configuration can be ISDN Access at the same time. A PC should have a network interface card that is capable of communicating With ISDN router This card is not unique in any way. General ethernet card for In the example this functionality is. In these configurations, ISDN is a common application telecommunications. The idea is Simple: To make "transport" as much as possible for office performance for a remote site Through an ISDN BRI connection.
This functionality includes:
Although the specifics of the ISDN implementation are still slightly different from the nation The relationship between any two systems in the nation, the world, is no longer possible, But fast practical
Different types of cable buses are used in ISDN.
Minimum bus configuration is the maximum length between NT and terminal devices 140 meters Terminal equipment can be connected anywhere in the bus.
Maximum length between NT and the terminal device in extended bus configuration 500 meters. Although there are some restrictions on where terminal equipment is Is connected to the bus.
In both small bus configurations and extended bus configurations, you can connect up to 8 Terminal device, but the maximum length between the two terminal devices is 50 Is the meter.
The point-to-point bus can be connected to a terminal device only in the configuration NT The maximum length between NT and terminal equipment is 750 meters.
An application is a WAN backup, where you use ISDN with a leased line. when The leased line overloads or activates the ISDN connection.
Another application has remote access. It can refer to Internet access or access to a LAN Away from the place
A third application is Symbian Voice, Fax and Data. It can be very convenient People working from home
ISDN can also be used as a WAN service, which connects two LANs to each other.
A popular application for ISDN is LAN connectivity. Max bandwidth between If BRI is used then LAN is 128 kbps. If PRI is used then the maximum bandwidth is 2 Mbps.
The ISDN call is automatically made by the router only when the data is sent Network on the other hand. Time of connection establishment is very short and there are There is practically no delay when traffic flows. A timer configured by the owner of the router After some time the ISDN connection can be set to disconnect.
One of the main uses of ISDN is the high speed of the Internet. At most For the Internet, such as audio and video applications, demand high bandwidth Satisfactory result Normal 28.8 Kbps is no longer sufficient. For alternative Individuals and small companies, use ISDN.
In the picture,e you can see the general configuration used by a small company. equipment ISDN is connected to ISDN via Router, which has BRI connections. in this matter The maximum bandwidth for internet communication which can be 128 kbps for a single user.
In the picture, we can see two types of configurations. The first type is an ISDN The card installed in the PC, which can communicate directly with NT. It's the cheapest Solution, but up to two users can have ISDN access.
In another type, an ISDN router is used. Many users in this configuration can be ISDN Access at the same time. A PC should have a network interface card that is capable of communicating With ISDN router This card is not unique in any way. General ethernet card for In the example this functionality is. In these configurations, ISDN is a common application telecommunications. The idea is Simple: To make "transport" as much as possible for office performance for a remote site Through an ISDN BRI connection.
This functionality includes:
- High-speed access to the user's LAN and file servers.
- Full access to the mailbox.
- Internet access.
In the picture we see a large office using PRI, ISDN connection. The advantage is that You can use the bandwidth you need. Can use a PRI connection up to 8s For 30-B channels. However, you can not use less than 8 B channels. A special solution for PRI Some of the PBX channels have to connect. Which are connected to the telephone PBX can access the ISDN network to access the public telephone service. Other b channels Data can be used for communication.
Frame Relay and ISDN is a common internetworking team, with frame relay handling. Main link and ISDN provide back-up capabilities instead of traditional asynchronous Connection.
Leased lines have two major limitations. The peak periods of traffic that are available overload Bandwidth, which leads to delays and delays. If the lease line is in the correct size, then one second
The leased line of any capacity is overkill. In fact, normal, non-peak traffic can be well below The current line data rate
A second limitation is the lack of redundancy with a single-leased line. For mission-critical Applications, as often happens when leased lines are used, it can be a serious one Limit with devastating consequences
Different provisions using dial-up lines can provide the necessary backup and overflow Bandwidth in a cheap and transparent way. Unfortunately, integration with dial-up backups Current leased lines can be a challenge. Most routers are not equipped to handle backups And overflow cost effectively.
The solution to this problem is the ISDN Basic Rate Interface Service which provides dial-up On demand of backup and bandwidth.
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