GE MDS ORBIT MCR Technical Manual page 102


Stale Packet Timeout - If the MAC is unable to transmit a packet in this time, it will drop the
packet. Milliseconds, DEFAULT= 1500, range from 0 to 65535.

Propagation Delay - Correction for the propagation delay of the RF signal. Enumeration of
20, 40, or 60 mile speed-of- light delay. DEFAULT = 40

Mcast Repeat – Multicast repeat number - Number of times to repeat downstream broadcast
and multicast data. DEFAULT = 3, range from 0 to 255.

Data Retries - Number of times to retry unicast data before declaring NACK. Valid values:
0—15, DEFAULT = 3.

Fragment Threshold - – This parameter controls the NIC's over the air fragmentation. It is
transparent to all network traffic and is independent of any IP fragmentation. Any packet
larger than the threshold will be broken up into packets up to the threshold size.Valid values:
0, 50—1500 Bytes, 0 is disabled. DEFAULT = 0.

Remote Age Time – Length of time, in seconds, of inactivity of the device before it is
disconnected. Valid values: 180-4294967295, DEFAULT = 600

Endpoint Age Time- Length of time in seconds if inactivity on this endpoint before it is
removed from the database. DEFAULT = 300. Range of 0 to 4294967295

Allow Retransmit – All traffic from the remotes is sent to the AP. When enabled the AP will
retransmit traffic from one remote to another based on the MAC address. It will also resend
any remotes broadcast traffic to all other remotes.

ARP Cache – Disabled by DEFAULT. When enabled, the radio will respond to ARP requests
intended for other network devices with known addresses. It will not forward the ARP to the
intended device

ADR Mode – Adaptive data rate mode controls whether the NIC will attempt to use different
modem speeds for different remotes. All downstream traffic uses the lowest rate; only
upstream traffic can use the variable rate. ADR setting is automatically learned by remotes, but
remotes modem must be set to Auto, or 125 for 125-250kbps, or 500 for 500-1250 kbps
operation.
125-250kbps – ADR will attempt to use the FHSS modems (125kbps and 250kbps) when
-
trying to determine the best modem for the remote.
500-1250kbps – ADR will use the DTS modems (500kbps, 1000kbps, 1000W kbps, and
-
1250 kbps) when attempting to determine the optimal rate.
none – ADR is not used and the static modem setting in nx-config is used for the modem.
-
(Default)

ADR Threshold – The threshold is an RSSI threshold. If the received signal is stronger than
the threshold the NIC will attempt to use a faster modem. ADR Threshold must be set for each
radio (Remotes and AP). This is advantageous in that you can run the majority of the network
in ADR mode, but if a particular remote has strong RSSI but difficult channel conditions you
can effectively disable ADR on that specific remote by setting the ADR threshold artificially
low.

Encryption Protocol – Encryption Protocol 2.0 provides the highest level of over the air
encryption security with a strong encryption key, but is not compatible with MCR-900 radios
running firmware earlier than 3.1.0. Encryption Protocol 1.0 provides compatibility with older
firmware by using the strong key when talking to units with firmware 3.1.0 and later, and a
less strong key when talking to units with firmware earlier than 3.1.0. DEFAULT 2.0. For
more information, refer to Product Bulletin PB15001_A, MCR-900 Encryption Issue
Resolution, available at http://www.gemds.com.
102 MDS Orbit MCR/ECR Technical Manual MDS 05-6632A01, Rev. F