RESPONDER Characteristic
RESPONDER CharacteristicAccess Server MappingIn 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 TypesLAT provides the following specific types of datagrams that facilitate this mapping:
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 |
|
|
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.