Supplying User Location Data to Telnet Servers

Supplying User Location Data to Telnet Servers

Introduction

When the access server creates a Telnet client connection, it automatically negotiates with the Telnet server to send port user data. If the server responds with a “send” message, the access server transmits the session port name and port number. Appropriate software on the server can then use the location data for each session to generate statistics about Telnet use. In these negotiations, the access server functions only as a Telnet client, not as the Telnet server.

Each time the Telnet server transmits IAC DO, the client sends the location data. In this way, the server can poll anytime for the user’s location. If the Telnet server does not respond with IAC DO, the session proceeds normally, but the client does not send the location data.

Example: TCP Messages to Poll Client User Location Data

The following example shows a series of TCP messages generated during negotiation between the Telnet client (the access server) and the Telnet server. The client starts the negotiation with IAC WILL SEND-LOCATION.

IAC WILL SEND-LOCATION IAC DO SEND-LOCATION

IAC SB SEND-LOCATION ascii-locationIAC SE IAC DO SEND-LOCATION

IAC SB SEND-LOCATION ascii-locationIAC SE

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The ascii-locationfield comprises the Telnet user’s port name and port number. The port number is stored in the access server NVRAM. The port name is also stored in NVRAM. It is the string specified by the DEFINE/CHANGE PORT NAME command, and it appears in the display for the LIST PORT command.

13-18 Configuring and Managing Telnet Servers