Operations Manual

OPERATIONS 4-16
O&M of the MCC-545B PACKET DATA RADIO
12/2000
If the end-to-end ACK is not received within the time-to-live limit, the 545B purges the message
from the queue and print the following message:
hh:mm:ss MESSAGE TIME-TO-LIVE EXPIRED, MSG.NO: sss,DESTN: name
You must then reenter the message. If this printout recurs often, you should examine the
performance of the equipment. Continued failure to transmit a message indicates that something
is wrong with the equipment, or the link (such as too much noise interference).
4.3.5 Receiving Messages
Whenever the header of a new message is received, the message is announced by the following
printout:
hh:mm:ss RECEIVING name:sss TXT sss/nn FROM name ROUTED TO: name
The 545B then generates an ACK of the message packet and transmits the ACK back to the
neighbor it received the message from:
hh:mm:ss TXTMSG ACK name:sss, nnnn CHARS FROM name
When the destination 545B receives a complete message, it prints the message to the same port
at which it was input at the source Station, e.g., it outputs it to the message port if it was input on
the message port at the source Station. Messages print in the following format:
hh:mm:ss MSG RECEIVED name:sss, xxxx CHARS
text........................................
** end-of-message **
where "name:sss" is the message serial number.
Messages are deleted as they are printed, unless they are also being forwarded to further
destinations.
4.3.6 Examining/Revising Message Queues
There are two types of queues for messages:
Queue Name Description
TXQ Transmit queue for all transmitting messages. There is a separate transmit queue
(Transmit for each neighbor Station in network. For example, if you enter a message for
Queue) DEST1, that message is placed in DEST1's transmit queue if DEST1 is a neighbor
or in a neighbor Station's transmit queue on the route to DEST1.