The .MPP Driver

The .MPP Driver Information about the low-level driver

Within the AppleTalk Manager, the .MPP driver implements the

LocalTalk Link Access Protocol (LLAP), the Datagram Delivery Protocol

(DDP), the Routing Table Maintenance Protocol (RTMP) stub, the

Name-Binding Protocol (NBP), and the AppleTalk Echo Protocol (AEP). The

AppleTalk Phase 2 version of the .MPP driver includes a new function that

returns information about the .MPP driver, functions that send messages to

routines in the AppleTalk Transition Queue, and a new wildcard character for

NBP.

Getting Information About the .MPP Driver

You can use the PGetAppleTalkInfo function to obtain information about the

.MPP driver. The PGetAppleTalkInfo function returns

• a pointer to the .MPP global variables

• a pointer to the .MPP driver's device control entry (DCE) data

structure

• configuration flags that indicate the status of certain conditions that

are set at startup

• a value (the selfSend flag) that indicates whether the node can send

packets to itself

• the range of network numbers for the network to which the node is

attached.

• the 8-bit node ID and 16-bit network number of the node

• the 8-bit node ID and 16-bit network number of the last router from

which the node has heard

• the maximum capacities of the .MPP driver, such as the maximum

number of protocol handlers and the maximum number of static sockets

allowed by this driver

• a pointer to the registered names queue

• the address of the node on the underlying data link (for example, the

Ethernet hardware address)

• the node's zone name

The data link address (for example, the Ethernet hardware address) and the

zone name are returned only for extended networks-that is, network types that

allow more than one network number per network. You must allocate memory

for and provide pointers to the data buffers into which the

PGetAppleTalkInfo function returns the data link address and zone name.

You use the laLength parameter to specify the length of the data link address

you want returned; the function returns the actual length of the data in the

laLength parameter and returns the data in the buffer you provide.

Note: Always use the PGetAppleTalkInfo function to obtain information about

the .MPP driver. You can no longer rely on the validity of the global

variables described in older documentation.