Blinky  Ansynchronous Transfer Mode (ATM)  Blinky


AAL
ATM Adaptation Layer defines how data is encapsulated into cells and how that data is reconstructed.
AAL1
ATM Adaptation Layer 1 that is used to fix the data rate services in real-time networks, such as voice.
AAL2
ATM Adaptation Layer 2 is intended for services that need real-time support but have VBR, such as compressed video for HDTV.
AAL3/4
ATM Adaptation Layers 3/4 are used for data services.
AAL5
ATM Adaptation Layer 5 is a low-overhead protocol used for LAN services. It is used for the transmission of data such as IP over ATM. The AAL5 is passed to the SAR which segments it into 48 byte cells.
ABR
Available Bit Rate in which data is delivered using the available bandwidth. Flow control is used to provide little or no data loss. A minimum bandwidth may be specified.
ARP
Address Resolution Protocol is an Internet protocol that takes care of translation of L_3 addresses to physical addresses and hide these addresses from the upper layers of the OSI model.
ATM
Asynchronous Transfer Mode that transports small fixed length packets called cells over a high-speed network using multiplexing and switching technology. ATM offers scalable range of speeds beginning at sub-T1 rates and increasing to 622Mbps and beyond. ATM Addresses are 20 bytes long.
BUS
Broadcast & Unknown Server that forwards broadcast, multicast, and unknown data frames to members of the ELAN.
CBR
Constant Bit Rate in which data flows continuous and steady with a guaranteed quality of service. Typically requires greater bandwidth.
CDV
Cell Delay Variation which has to do with jitter.
CIR
Committed Information Rate ensures a "fair" access to the network resources for all users, currently active in the network, via their PVCs.
CLR
Cell Loss Ratio in which the number of cells are lost per connection.
CTD
Cell Transfer Delay which is the time it takes to get across the net.
DLCI
The DLCI is a network address number between 16 and 991 which is used as the address for each end of a PVC.
E.164
Address standard for ISDN.
ELAN
Emulated LAN
EPD
Early Packet Discard
FRS
Frame Relay Service is a data communications service that provides for data connectivity between or among widely distributed end-user locations.
FUNI
Framed User Network Interface designed as a means for ATM devices to use lower speed links such as T-1.
GFC
General Flow Control
H.320
Circuit-switched Digital ISDN, non-ATM video. The ATM CellPath from Fore Systems provides ATM internetworking with ISDN PRI and T1 inband directly.
CLP
Cell Loss Priority
CPCS
Common Part Convergence Subsystem
DSP
Domain Specific Part
DXI
Data Exhange Interface that operates in three modes: 1A for AAL5 providing up to 1,023 VCs, 1B operates with AAL3/4 and AAL5 providing up to 1,023 VCs, and mode 2 operates with AAL3/4 and AAL5 providing up to 16,777,215 VCs.
Frame
Variable-length packet of data used by traditional LANs such as Ethernet and Token Ring as well as WAN services such as X.25 or Frame Relay.
HEC
Header Error Control
IDP
Initial Domain Part
IEEE 802
Addressing for LANs.
ILMI 4.0
Interim Link Management Interface that defines the interfaces between public and private networks and assists in auto-registration of ATM devices.
ITU
International Telecommunications Union
LANE
Local Area Network Emulation that provides the functionality of a single LAN segment (IEEE 802.5 Token Ring), or IEEE 802.3 Ethernet).
LEC
LANE Emulation Client that presents a MAC-level interface to the higher layer protocols and implements LUNI when communicating with other components on the ELAN.
LECS
LANE Emulation Configuration Server that provides configuration and ELAN membership information to the clients.
LES
LANE Server that maintains a cache of MAC-to-ATM addresses and is an address resolution server.
LIS
Logically Independent Subnetworks
LUNI
LAN User Network Interface
MPLX
Multi-Protocol Labeling standard that routes packets from subnet to subnet using a label to simplify packet forwarding.
MPOA
Multiple Protocol of ATM that enables layer-three protocols such as IP and IPX to operate directly over ATM. MPOA is responsible for five major operations: configuration, discovery, target resolution, connection management, and data transfer.
NBMA
Non-Broadcast Multi-Access refers to a nonbroadcast subnetwork, i.e. X.25.
NHRP
New High Routing Protocol
NHRP
Next Hop Resolution Protocol discovers and correlates a layer 3 (the internetwork layer address) and the NBMA subnetwork address of the NBMA next hop to a destination station.
NNI
Network-to-Network Interface
OSI NSAPs
Open Systems Interface Network Single Address Points for addressing.
OSPF
Open Shortest Path First
PDU
Packet Data Unit
PPD
Partial Packet Discard
PNNI
Private Network-to-Network Interface
PUNI
Public User Network Interface
PVC
Permanent Virtual Channel defines each switch's database.
Q.2931 (Q.93B)
Signaling for ATM.
QoS
Quality of Service allows for five classes of service: CBR/ABR/UBR/rt-VBR, nrt-VBR. Class 1 is CBR, Class 2 is VBR, Class 3 is CO, Class 4 is CNLS, and Class 0 is UBR.
PBX
Private Branch Exchange
PT
Payload Type
RSVP
Resource Reservation Protocol checks to see if the other connection can support the QoS, if not the reservation is refused.
RTP
Realtime Transport Protocol mapped into a ATM network can allow for Ethernet QoS across the ATM cloud.
SAR
Segmentation and Reassembly
SIP
SMDS Interface Protocol
SNAP
Subnetwork Access Protocol
SONET/SDH
The framing format used to carry cells at speeds of 155 Mbps and above.
SSCS
Service Specific Convergence Subsystem
SMDS
Switched Multimegabit Data Service is a public, packet-switched data service.
SVC
Switched Virtual Channel requires signaling and addressing to setup connections "on-the-fly".
TDM
Time Division Multiplexing
TM
Traffic Management provides specifications for traffic control to limit congestion and maximize bandwidth on an ATM network.
UBR
Unspecified Bit Rate in which data is delivered on a "Best Effort" basis with no guarantees.
UNI v3.1
User Network Interface v3.1 that defines call setup and QoS negotiation.
UNI Cell
UNI Cell is composed of seven things: GFC (set to zeroes), VPI (8 bits), VCI (16 bits), PT (3 bits, type of payload), CLP (1 bit), HEC (8 bits), and a Payload of 48 Octets.
UNI, Private
Private User Network Interface
VBR
Variable Bit Rate
VC
Virtual Channel
VCC
Virtual Channel Connection
VCI
Virtual Channel Identifier is one of the addressing fields used by ATM which is a connection-oriented system, similar to X.25 or Frame Relay.
VCL
Virtual Channel Link
VLAN
Virtual Local Area Network
VP
Virtual Path, gets you a wide distributed path with many VCs and provides a through path for data, voice, or mltimedia.
VPC
Virtual Path Connection
VPI
Virtual Path Identifier is the second address field used by ATM which is a common requirement for WAN installations.
VPL
Virtual Path Link

ag_button3

Date of last revision: 17 December 2001
Extracted from the ATM Forum, web site: ATM Forum Glossary ; Edward Jacques, March 1997; FORE Systems, White Paper, April 1996; Network Computing, "ATM Access", November 15, 1996; ATM Volume III "Internetworking with ATM" by Uyless Black, and the Xylan Technology Workshop, 1997,