User's Manual Part 1

6: Installation & Diagnostic Tools
APCD-LM043-8.0 (DRAFT C) 101
Measuring Radio Link Connectivity
Different sized pings can help you gauge the quality of the wireless link. A good quality
wireless link can pass large sized packets without any loss. If a link is of poor quality, small
sized pings may be successful, while large sized pings may experience lost packets or
packets that cannot transmit at all. CCUs and EUMs support pings with packets between 64
and 1460 bytes in length. A common practice is to ping a link with 64-byte packets and then
with 1460-byte packets. You can then compare the success rate of the different ping sizes.
The ping utility reports the packet loss rate after as many as four retries. In addition to
monitoring the packet loss rate, you should evaluate the ping times. Transmit retry rates
provide a better indication of the radio link quality.
To Measure Radio Link Connectivity by Pinging with 64-byte Packets
1. At the CCU, use the auth command to check that the EUM is authorized, either
statically, through the default, or through RADIUS.
2. At the CCU, use the
air command to check that the EUM is registered. (For more
information, refer to
Registration Table (CCU only) on page 240.)
3. At the CCU, type
ping <aaa.bbb.ccc.ddd>, where <aaa.bbb.ccc.ddd> is the
IP address of the EUM, and press
Enter.
Or, at the EUM, type
ping <aaa.bbb.ccc.ddd>, where <aaa.bbb.ccc.ddd> is
the IP address of the CCU, and press
Enter.
60:03:3a> ping 192.168.22.2
Press any key to stop (time resolution: 16 ms)
PING 192.168.22.2: 56 data bytes
64 bytes from 192.168.22.2: icmp_seq=0. time=80. ms
64 bytes from 192.168.22.2: icmp_seq=1. time=48. ms
64 bytes from 192.168.22.2: icmp_seq=2. time=32. ms
64 bytes from 192.168.22.2: icmp_seq=3. time=32. ms
64 bytes from 192.168.22.2: icmp_seq=4. time=32. ms
64 bytes from 192.168.22.2: icmp_seq=5. time=48. ms
64 bytes from 192.168.22.2: icmp_seq=6. time=48. ms
64 bytes from 192.168.22.2: icmp_seq=7. time=48. ms
64 bytes from 192.168.22.2: icmp_seq=8. time=32. ms
64 bytes from 192.168.22.2: icmp_seq=9. time=32. ms
----192.168.22.2 PING Statistics----
10 packets transmitted, 10 packets received, 0% packet loss
round-trip (ms) min/avg/max = 32/43/80
60:03:3a>
To Measure Radio Link Connectivity by Pinging with the Maximum Packet Size
1. At the CCU, use the auth command to check that the EUM is authorized, either
statically, through the default, or through RADIUS.
2. At the CCU, use the
air command to check that the EUM is registered. (For more
information, refer to
Registration Table (CCU only) on page 240.)
3. At the CCU, type
ping <aaa.bbb.ccc.ddd> 1460, where <aaa.bbb.ccc.ddd>
is the IP address of the EUM, and press
Enter.
Or, at the EUM, type
ping <aaa.bbb.ccc.ddd> 1460, where
<aaa.bbb.ccc.ddd> is the IP address of the CCU, and press Enter.