Protocol Logging During Ping

Last updated: April 14, 2005

This section is only applicable to the lab applications.

Ping data passing between the test set and the access terminal can be logged using the Wireless Protocol Advisor (WPA) (see Protocol Logging ). The log results during ping depend on the method used. Here are several methods and descriptions of the log results.

Method 1: Ping the access terminal from the Test Set

To capture a protocol log while pinging the access terminal from the test set, start a capture in the WPA and then follow the steps in Ping the DUT from the test set .

Looking at the Protocol Log

Note that the Source Address for the IP datagram in the Forward/Down direction is an unknown IP address (130.29.181.203). This is an internal address the test set uses to originate IP traffic from the test set to the access terminal.

See Ping Log for more information about the log.

Method 2: Ping an Alternate IP Address From the Test Set

To capture a protocol log while pinging an alternate IP address from the test set, start a capture in the WPA and then follow the steps in Ping an alternate address from the test set .

If your Alternate Ping Address is anything but the access terminal address, the test set's protocol logging does not log this ping. The test set's logging only captures messages exchanged between the test set and the access terminal. If you have a network logging device on your LAN, it will show that the source IP address is the test set's LAN IP address. If your Alternate Ping Address is the access terminal address, then the data is logged by the test set, and the Source Address for the datagram in the Forward/Down direction that contains the ping data is the same IP address as in Method 1.

Method 3: Using Ping From Other Devices

Any device on the network that has a ping feature can ping any other device, including the access terminal. For example, if you have a PC on the LAN that the test set is connected to, you can use ping from that PC to ping the access terminal.

Example procedure of pinging the access terminal from another device (e.g. a Windows PC):

Start protocol logging. See Protocol Logging .
Open a MS DOS command prompt on the PC.
Type the following command
ping xxx.xxx.xxx.xxx

where xxx.xxx.xxx.xxx is the IP address of the access terminal.
The ping should respond as normal.
Stop logging.

In this case, the Source Address for the datagram in the For/Down direction that contains the ping data is the IP address of your PC.

Ping Log

The Ping can be logged using the Wireless Protocol Advisor (WPA) (see Protocol Logging ), and certain information can be derived from the log of the Ping.

"For/Down" in the "Direction" column of the WPA indicates that this is a forward/down link message and is therefore passing from the test set to the access terminal.
Ping is an Internet Control Message Protocol (ICMP) protocol message.
Message Type is Echo Message, which is the instruction to the peer layer at the destination address to generate an Echo Reply message.
The IP address of the access terminal is the Destination Address on the forward/down link datagram and is the Source Address on the reverse/up link datagram. The alternate address is an address within the test set that originated the Ping data packet.
The Type, Code, Checksum, Identifier and Sequence Number are all listed.