Telnet client negotiation not working properly

Question

I am designing telnet client, which negotiates telnet options. I send desired commands to server, and process server's requests and responses. But at least color terminal identification has no effect: remote Linux server continues sending data without color ESC sequences until I explicitly tell it (through its dialog) that my client supports color.

However windows telnet and hyperterminal is being fed by the color information just after telnet negotiation, and I am looking for what they do I do not. Here's what I see:

telnet

hyperterminal

I see that server performs 255 cursor right and 255 cursor down, and then requests cursor position report, and client reports ESC [ 24;80R (which is correct), and just after this server starts color communication.

Here's what my client does

It does not have ESC [ R command supported, and does not respond for reporting cursor position. I must say that server seem to wait for several seconds for something exactly at the time when it performs these right/down cursor movements.

If it the issue why I do not have color data from the server, or there's something else you can see in the operation of my client?

Interesting that I have a video of another client which also is not expected to support ESC R command, but I see server starts sending ESC color codes after negotiation. So I have a feeling that it may not be this cursor report command issue.

Answer 1

Answer: after implementation of the "report position" response of the client to the server, server sends ESC color sequences now. Thus this functionality was vital for the general client-server handshaking.