Specifications

Configuring LAT Characteristics
7-16
RESPONDER Characteristic
Access Server Mapping
In order to connect to other nodes on the LAN, the access server must be able to
map node names, port names, and services to specific nodes.
Datagram Types
LAT provides the following specific types of datagrams that facilitate this
mapping:
LAT V5.2 nodes operating as LAT masters can address Solicit Information
datagrams to V5.2 slave nodes and be almost assured of a direct response.
However, nodes operating as V5.1 masters can only address Solicit Information
datagrams to other V5.1 masters since V5.1 slaves do not enable multicast
addresses for the reception of directory service datagrams. Therefore, V5.1 and
V5.2 nodes are allowed to respond to Solicit Information datagrams for slave
nodes that cannot respond for themselves.
The RESPONDER characteristic determines whether the access server may act as
an agent for other nodes. By configuring one or more access servers to act as
responders, the other access servers can operate with a node limit of 1 and still be
assured access to LAT services. This frees up the dynamic memory and reduces
the overhead that would otherwise have been required to maintain the LAT node
database.
Datagram Name Description
Service Announcement A mulicasted datagram used by slave nodes to
advertise services
Solicit Information A multicasted or physically addressed datagram used
by any node to solicit service information from
another node
Response Information A physically addressed datagram sent in response to a
received Solicit Information message