A dual PRI could have 24 + 23 = 47 B-channels and 1 D-channel ( often called " 47B + D "), but more commonly has 46 B-channels and 2 D-channels thus providing a backup signaling channel.

In some countries, like the Netherlands or Germany, it is possible to use a stripped version of X. 25 via the D-channel of an ISDN-2 ( or ISDN BRI ) connection for low volume applications such as point-of-sale terminals ; but, the future of this service in the Netherlands is uncertain.

The Primary Rate Interface ( PRI ) consists of 23 64-kbit / s B-channels and one 64-kbit / s D-channel using a T1 line, often referred to as " 23B + D ", ( North American and Japanese standard ) or 30 B-channels and one D-channel using an E1 line ( Europe / rest of world ).

The net bit rate of ISDN2 Basic Rate Interface ( 2 B-channels + 1 D-channel ) of 64 + 64 + 16 = 144 kbit / s also refers to the payload data rates, while the D channel signalling rate is 16 kbit / s.

The following is an example of a Primary Rate ( PRI ) ISDN call showing the Q. 921 / LAPD and the Q. 931 / Network message intermixed ( i. e. exactly what was exchanged on the D-channel ).

Both rates include a number of B-channels and a D-channel.

The D-channel carries control and signaling information.

The Basic Rate Interface consists of two 64-kbit / s B-channels and one 16-kbit / s D-channel.

D-channel in ISDN is an example of out-of-band and CCS signaling methods.

Some aircraft, the Panavia Tornado for example, retain a very basic hydro-mechanical backup system for limited flight control capability on losing electrical power, in the case of the Tornado this allows rudimentary control of the stabilators only for pitch and roll axis movements.

Spanning tree also allows a network design to include spare ( redundant ) links to provide automatic backup paths if an active link fails, without the danger of bridge loops, or the need for manual enabling / disabling of these backup links.

Its new features include point in time recovery via journaling ( which also allows recoverability without the performance penalty of synchronous writes ), incremental backup, batch statement operations, new Unicode character encodings, and a new ODBC driver.

The password system is replaced by battery backup, which allows saving up to 12 characters.

Electrical power distribution in each SRB consists of orbiter supplied main DC bus power to each SRB via SRB buses labeled A, B and C. Orbiter main DC buses A, B and C supply main DC bus power to corresponding SRB buses A, B and C. In addition, orbiter main DC bus C supplies backup power to SRB buses A and B, and orbiter bus B supplies backup power to SRB bus C. This electrical power distribution arrangement allows all SRB buses to remain powered in the event one orbiter main bus fails.

Multicasting allows sending a single backup image simultaneously to other machines without putting greater stress on the network than by sending an image to a single machine.

In " Full Disk " mode, DVD Shrink allows the user to make a functionally identical backup copy without changes ; alternatively random audio / subtitle streams can be deselected.

Volume format updated to allow for a built-in backup, which allows recovery of containers with minor damage to their headers.

As a backup a-high guyed, ground-fed lattice steel mast radiator is available on the site, which only allows an omnidirectional radiation pattern.

** Shadow Copy-is a feature introduced by Microsoft with Windows Server 2003, that allows taking manual or automatic backup copies or snapshots of a file or folder on a specific volume at a specific point in time.

Shadow Copy ( Volume Snapshot Service or Volume Shadow Copy Service or VSS ), is a technology included in Microsoft Windows that allows taking manual or automatic backup copies or snapshots of data, even if it has a lock, on a specific volume at a specific point in time over regular intervals.

CST not only improves reliability of services supplies and allows easy maintenance and new installations, it also has 100 % emergency backup services and the capacity for expansion to meet changing utility needs.

This knot is very popular in caving as it allows the load to be spread between two anchor points, reducing the stress placed on them and providing a backup should one fail.

; Off-Line Backup: Off-Line Backup allows along with and as part of the online backup solution to cover daily backups in time when network connection is down.

A scheduler / command-line frontend known as SaraB allows the Towers of Hanoi, Grandfather-Father-Son, or any custom backup rotation strategy, and modifications are available for PAR file support.

Clients may maintain a backup data center at a separate location that allows them to instantaneously continue operations in the instance of system failure.

Voluming allows the ability to compress and split backup data into separate parts for storage on smaller, removable media such as CDs.

Virtualizing the disk storage as tape allows integration of VTLs with existing backup software and existing backup and recovery processes and policies.

The most common data source for TSM is the TSM Backup / Archive Client, which allows backup and restore of data " selectively ," and " incrementally ".

soil pollution from toxic chemicals such as DDT ; energy blockade, the result of conflict with Azerbaijan, has led to deforestation when citizens scavenged for firewood ; pollution of Hrazdan ( Razdan ) and Araks Rivers ; the draining of Sevana Lich ( Lake Sevan ), a result of its use as a source for hydropower, threatens drinking water supplies ; restart of Metsamor nuclear power plant without adequate ( IAEA-recommended ) safety and backup systems

Although not officially announced, the original backup crew consisted of Fred Haise ( CDR ), William R. Pogue ( CMP ) and Gerald Carr ( LMP ) who were targeted for the prime crew assignment on Apollo 19.

At this point, during tests of the CSM's steerable rocket engine in preparation for the burn to modify the craft's orbit, a malfunction occurred in the engine's backup system.

Vick, who saw minimal playing time in 2001, playing backup and learning the system under then-starting quarterback Chris Chandler, was designated starting quarterback for the 2002 season.

During the 1980s, Grant was also a backup singer for Bill Gaither.

But Austria-Hungary failed to secure German backup for a firm reaction.

The Blues use this jet for backup, and to give demonstration rides to VIP civilians.

She also trained for the mission STS-83 to be the backup for Donald A. Thomas ; however, as he recovered on time, she did not fly that mission.

Coleman was assigned as a backup U. S. crew member for Expeditions 19, 20 and 21 and served as a backup crewmember for Expeditions 24 and 25 as part of her training for Expedition 26.

This is a protective mechanism for the heart, to compensate for an SA node that is no longer handling the pacemaking activity, and is one of a series of backup sites that can take over pacemaker function when the SA node fails to do so.

The Elektronika MK-52 calculator ( using the extended B3-34 command set, and featuring internal EEPROM memory for storing programs and external interface for EEPROM cards and other periphery ) was used in Soviet spacecraft program ( for Soyuz TM-7 flight ) as a backup of the board computer.

A DBMS provides facilities for controlling data access, enforcing data integrity, managing concurrency control, and recovering the database after failures and restoring it from backup files, as well as maintaining database security.

* Data administration subsystem helps users manage the overall database environment by providing facilities for backup and recovery, security management, query optimization, concurrency control, and change management.

A person auditioning for a role as a bassist in some styles of pop or rock music may be expected to be able to demonstrate the ability to perform harmony vocals as a backup singer.

The only successful drop kick in the NFL since the 1941 NFL Championship game was by Doug Flutie, the backup quarterback of the New England Patriots, against the Miami Dolphins on January 1, 2006, for an extra point after a touchdown.