Cal Amp VIPER SC+ 100 series User Manual - page 126
Viper SC+™ IP Router for Licensed Spectrum PN 001-5008-000 Rev. C
| Page 116
Duplicate Packet Removal (Needed for Rx PER) — This option must be enabled in order to calculate the PER. It
controls if the packets sent over the air will contain or not the packet sequence number (used by duplicate packet
detection and PER calculation). By default, it is disabled to preserve compatibility with firmware versions prior to
V3.3_R201109191700. If this option is enabled facing the older firmware versions (prior to V3.3_R201109191700), the
RF communication will fail.
Remote Statistics Table
This Unit — Centered at the top of the table provides the RF MAC address of the Viper for reference.
Table columns are as follows.
Remote Unit — The RF MAC address of the neighboring remote unit. This table is updated every time the Viper sends
(or receives) data to (or from) the remote unit. If the RF MAC address is prefixed with an asterisk (*, or star), it means
this unit was learned of through a Relay Point (RP) unit.
RF IP Address — The RF IP Address of the remote unit.
Received Packets — Number of IP packets sent by the remote unit to this unit and received. A packet is bad, or failed,
if at least one of the CRC, the length, or the system identifier is incorrect, or it is simply missing (not received at all by
this unit). The Viper is able to detect missing packets because of the sequence number in each packet.
PER — Packet Error Rate is expressed as a percentage that indicates the percentage of packets that have failed to be
successfully transmitted or received over the RF link.
When the Packet Error Rate is indicated by a question mark (?), it is because the unit cannot determine the
value. This is because the sequence number is not included in the packets received over the air or because no IP
packet has been received yet. To make sure a remote unit includes a sequence number in its packets, the “OIP
duplicate packet removal” feature must be enabled on it.
Transmitted Packets — Total number of IP packets transmitted on the RF interface (good and bad packets) to the
remote unit (unicast or broadcast).
A packet is bad (failed) if notification was not received from the remote unit of the arrival of the packet.
The transmit Packet Error Rate (PER) is calculated using the same formula as explained earlier.
When the Packet Error Rate is indicated by a question mark (?), it is because the unit cannot determine the value.
This is because the “RF ACK” feature is not enabled on this unit or no IP packet has been transmitted yet. The “RF
ACK” feature lets the unit know that the packet has made it to the remote unit.
RSSI — The most-recent Received Signal Strength Indicator (RSSI) from the remote unit. Each time a new packet is
received from the remote unit, the RSSI in this table is calculated and updated.
SNR — The most-recent Signal to Noise Ratio (SNR) from the remote unit. Each time a new packet is received from the
remote unit, the SNR in this table is calculated and updated.
Refresh — Click Refresh to update the statistics to show the most current information available.
Clear (Zero) Interface Stats — Clicking Clear (Zero) Interface Stats (or cycling power to the Viper) will reset all statistics
to zero.