D channel
Data channel. Full-duplex, 16-kbps (BRI), or 64-kbps (PRI) ISDN channel. Compare with B channel.

datagram
Logical grouping of information sent as a network layer unit over a transmission medium without prior establishment of a virtual circuit. IP datagrams are the primary information units in the Internet. The terms cell, frame, message, packet, and segment
also are used to describe logical information groupings at various layers of the OSI reference model and in various technology circles.

decrypt
Cryptographically restore ciphertext to the plaintext form it had before encryption.

Decryption
Reverse application of an encryption algorithm to encrypted data, thereby restoring that data to its original, unencrypted state. See also encryption. [Read more…]

CA
 Certification authority. Entity that issues digital certificates (especially X.509 certificates) and vouches for the binding between the data items in a certificate.

CA certificate
[Digital] certificate for one CA issued by another CA.

Call-back
a mechanism to place a call to a pre-defined or proposed location (and address) after receiving valid ID parameters.

CAR
Committed access rate. The CAR and DCAR (distributed CAR) services limit the input or output transmission rate on an interface or subinterface based on a flexible set of criteria.

Category 5 cabling
One of five grades of UTP cabling described in the EIA/TIA-586 standard. Category 5 cabling can transmit data at speeds up to 100 Mbps. Category 5E can transmit data up to 1Gbps. [Read more…]

backbone
Part of a network that acts as the primary path for traffic that is most often sourced from, and destined for, other networks.

bandwidth
The difference between the highest and lowest frequencies available for network signals. The term also is used to describe the rated throughput capacity of a given network medium or protocol. The frequency range necessary to convey a signal measured in units of hertz (Hz). For example, voice signals typically require approximately 7 kHz of bandwidth and data traffic typically requires approximately
50 kHz of bandwidth.

BGP
Border Gateway Protocol. Interdomain routing protocol that replaces EGP. BGP exchanges reachability information with other BGP systems. It is defined by RFC 1163. See also BGP4 and EGP. [Read more…]

10BaseT
10-Mbps baseband Ethernet specification using two pairs of twisted-pair cabling (Categories 3, 4, or 5): one pair for transmitting data and the other for receiving data. 10BaseT, which is part of the IEEE 802.3 specification, has a distance limit of approximately 328 feet (100 meters) per segment

100BaseFX
A 100-Mbps baseband Fast Ethernet specification using two strands of multimode fiber-optic cable per link. To guarantee proper signal timing, a 100BaseFX link cannot exceed 1312 feet (400 meters) in length. Based on the IEEE 802.3 standard.

100BaseT
100-Mbps baseband Fast Ethernet specification using UTP wiring. Like the 10BaseT technology on which it is based, 100BaseT sends link pulses over the network segment when no traffic is present. However, these link pulses contain more information than those used in 10BaseT. Based on the IEEE 802.3 standard. [Read more…]