initiates the transmission of tokens and provides token
error recovery facilities.Any active adapter on the ring
has the ability to provide the active monitor function if
the current active monitor fails.
address. In data communication, the unique code
assigned to each device, workstation, or user connected
to a network.
address mapping table (AMT). Atable, maintained
within theAppleTalk router, that provides a current
mapping of node addresses to hardware addresses.
address mask. For internet subnetworking, a 32-bit
mask used to identify the subnetwork address bits in the
host portion of an IP address. Synonymous with

subnet

mask

and

subnetwork mask

.
address resolution. (1)A method for mapping
network-layer addresses to media-specific addresses.
(2) See also

Address Resolution Protocol (ARP)

and

AppleTalkAddress Resolution Protocol (AARP)

.
Address Resolution Protocol (ARP). (1) In the
Internet suite of protocols, the protocol that dynamically
maps an IP address to an address used by a supporting
metropolitan or local area network such as Ethernet or
token-ring. (2) See also

Reverse Address Resolution

Protocol (RARP)

.
addressing. In data communication, the way in which
a station selects the station to which it is to send data.
adjacent nodes. Twonodes connected together by at
least one path that connects no other node. (T)
Administrative Domain. Acollection of hosts and
routers, and the interconnecting networks, managed by
a single administrative authority.
Advanced Peer-to-Peer Networking (APPN). An
extension to SNAfeaturing (a) greater distributed
network control that avoids critical hierarchical
dependencies, thereby isolating the effects of single
points of failure; (b) dynamic exchange of network
topology information to foster ease of connection,
reconfiguration, and adaptive route selection; (c)
dynamic definition of network resources; and (d)
automated resource registration and directory lookup.
APPN extends the LU 6.2 peer orientation for end-user
services to network control and supports multiple LU
types, including LU 2, LU 3, and LU 6.2.
Advanced Peer-to-Peer Networking (APPN) end
node. Anode that provides a broad range of end-user
services and supports sessions between its local control
point (CP) and the CP in an adjacent network node. It
uses these sessions to dynamically register its
resources with the adjacent CP (its network node
server), to send and receive directory search requests,
and to obtain management services.An APPN end
node can also attach to a subarea network as a
peripheral node or to other end nodes.
Advanced Peer-to-Peer Networking (APPN)
network. Acollection of interconnected network nodes
and their client end nodes.
Advanced Peer-to-Peer Networking (APPN) network
node. Anode that offers a broad range of end-user
services and that can provide the following:
vDistributed directory services, including registration of
its domain resources to a central directory server
vTopologydatabase exchanges with other APPN
network nodes, enabling network nodes throughout
the network to select optimal routes for LU-LU
sessions based on requested classes of service
vSession services for its local LUs and client end
nodes
vIntermediate routing services within anAPPN network
Advanced Peer-to-Peer Networking (APPN) node.
AnAPPN network node or an APPN end node.
agent. Asystem that assumes an agent role.
alert. Amessage sent to a management services focal
point in a network to identify a problem or an impending
problem.
all-stations address. In communications, synonym for

broadcast address

.
American National Standards Institute (ANSI). An
organization consisting of producers, consumers, and
general interest groups, that establishes the procedures
by which accredited organizations create and maintain
voluntary industry standards in the United States. (A)
analog. (1) Pertaining to data consisting of
continuously variable physical quantities. (A) (2)
Contrast with

digital

.
AppleTalk. Anetwork protocol developed by Apple
Computer,Inc. This protocol is used to interconnect
network devices, which can be a mixture ofApple and
non-Apple products.
AppleTalkAddress Resolution Protocol (AARP). In
AppleTalknetworks, a protocol that (a) translates
AppleTalknode addresses into hardware addresses and
(b) reconciles addressing discrepancies in networks that
support more than one set of protocols.
AppleTalkTransaction Protocol (ATP). In AppleTalk
networks, a protocol that provides client/server request
and response functions for hosts accessing the Zone
Information Protocol (ZIP) for zone information.
APPN network. See
Advanced Peer-to-Peer

Networking (APPN) network

.
APPN network node. See
Advanced Peer-to-Peer

Networking (APPN) network node

.
448 MRS V3.2 Protocol Config Ref Vol2