TS4000 Radio Modem User’s Manual
AirNet Packet Protocol
36
Control Description
Enable Multicast
Reception
This control enables the multicast capability of the modem
and also enables the entry of multicast groups.
Multicast Groups
This control is a list of multicast addresses. These
addresses have the same range as the group addresses.
The user can use as few or as many (up to the list size)
multicast groups as desired.
By default, a modem accepts two kinds of broadcasts.
Network broadcasts are received by all modems.
Group broadcasts are received by modems with the same group address as
the transmitting modem.
Control Description
Max Retries
This control sets the maximum number of transmit retries.
A retry is attempted if a packet is sent and an acknowledge
packet is not received within the time defined by the packet
timeout control. After the maximum number of retries have
been attempted the packet is cleared from the transmit
buffer. Retries do not apply to any kind of broadcast
transfers or individual transfers without acknowledgment.
Max Packet Size
This control defines the maximum packet size in bytes.
Any burst that is larger than this number of bytes will be
broken up into multiple packets with this maximum packet
size.
Note that there is a difference between bytes and
asynchronous characters. A byte is always eight bits of
data. The number of bits in an asynchronous character is
dependent on the setting of the asynchronous character
control fields.
Packet Timeout
The packet timeout is the amount of time the modem waits
for an acknowledgment before re-sending a packet (see
Network Setup - Setting Packet Timeout).
Packet Operation