Lecture 6: ISDN 2nd semester 1439-1438 By: Adal ALashban http://www.ciscopress.com/articles/article.asp?p=29737&seqNum=2 By: Adal ALashban

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais What is ISDN ISDN -Integrated Services Digital Network. It is an international standard for end to end digital transmission of voice, data and signaling. It can operate over copper based systems and allows the transmission of digital data over the telecommunications networks, typically ordinary copper based systems and providing higher data speeds and better quality than analogue transmission. Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

a local loop technology ISDN is a local loop technology. ISDN is deployed between the service provider's CO and the customer's premises This means that from local central office (CO) to premises it is ISDN. However, on the other side of CO's switch, it can be just about anything, such as ATM or SONET/SDH. Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais The ISDN Network The building blocks of ISDN are Bearer channels (B channels) and Data channels (D channels). The B channels are used for the transmission of customer video, voice, and data. The D channel is used for call-control signaling. There are some cases in which the D channel can be used for data applications. Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais ISDN Channels There are two types of channel that are found within ISDN. These are the 'B' and 'D' channels. The B or 'bearer' channels are used to carry the payload data which may be voice and / or data The d or 'Delta' channel is intended for signaling and control, although it may also be used for data under some circumstances. Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais ISDN Access Options There are two levels of ISDN access that may be provided. These are known as BRI and PRI Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais Basic Rate Interface BRI (Basic Rate Interface) - This consists of two B channels, each of which provides a bandwidth of 64 kbps under most circumstances. One D channel with a bandwidth of 16 kbps is also provided. Together this configuration is often referred to as 2B+D. The basic rate lines connect to the network using a standard twisted pair of copper wires. The data can then be transmitted simultaneously in both directions to provide full duplex operation Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Primary Rate Interface PRI (Primary Rate Interface) - This configuration carries a greater number of channels than the Basic Rate Interface and has a D channel with a bandwidth of 64 kbps. The number of B channels varies according to the location. Within Europe and Australia a configuration of 30B+D has been adopted providing an aggregate data rate of 2.048 Mbps (E1). For North America and Japan, a configuration of 23B+1D has been adopted. This provides an aggregate data rate of 1.544 Mbps (T1). Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais ISDN Usage ISDN is in use around the world, but with the introduction of ADSL it is facing strong competition. The technology never gained much market share in the USA, although it used in other countries. It is used in many areas, particularly where existing services need to be maintained, or where compatibility needs to be guaranteed. In Japan it became reasonably popular in the late 1990s although it is now in decline with the advent of ADSL. The system was also introduced in Europe where providers such as BT, France Telecom and Deutsche Telekom introduced services. Created By Dr.Najla AlNabhan edited by Maysoon AlDuwais

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